Sensory - Vision Development - Revision history

Z8600021 at 01:26, 25 Ocak 2024

2024-01-25T01:26:58Z

← Older revision		Revision as of 12:26, 25 Ocak 2024
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	==Lens==		==Lens==
	[[File:Stage_22_image_155.jpg\|thumb\|Human Lens (Carnegie stage {{~~CS222~~}})]]		[[File:Stage_22_image_155.jpg\|thumb\|Human Lens (Carnegie stage {{CS22}})]]
	The lens or crystalline lens or aquula (Latin, aquula = a little stream) has a key role in focussing light (with the cornea) upon the neural retina. The lens embryonic origin is from surface ectoderm of the sensory placodes that form in the head region (More? Week 4 - Placodes). The lens focusses by refracting light as it passes through the biconvex lens, which can be altered in shape (accommodation) by surrounding ciliary muscles. These ciliary muscles are activated (contracted) by parasympathetic innervation from the ciliary ganglion itself innervated by the oculomotor nerve (Cranial Nerve III) (More? Cranial Nerves).		The lens or crystalline lens or aquula (Latin, aquula = a little stream) has a key role in focussing light (with the cornea) upon the neural retina. The lens embryonic origin is from surface ectoderm of the sensory placodes that form in the head region (More? Week 4 - Placodes). The lens focusses by refracting light as it passes through the biconvex lens, which can be altered in shape (accommodation) by surrounding ciliary muscles. These ciliary muscles are activated (contracted) by parasympathetic innervation from the ciliary ganglion itself innervated by the oculomotor nerve (Cranial Nerve III) (More? Cranial Nerves).

Z8600021 at 06:15, 26 February 2022

2022-02-26T06:15:31Z

← Older revision		Revision as of 17:15, 26 February 2022
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	==Introduction==		==Introduction==
	[[File:Historic_retina_drawing.jpg\|right\|300px]]		[[File:Historic_retina_drawing.jpg\|right\|300px]]
			[[File:Human-retina-01.jpg\|thumb\|300px\|Adult Human Retina histology{{#pmid:12186651\|PMID12186651}}]]
	These notes introduce {{vision}} development of the eye: induction and regional specification of the eye structures, maturation and formation of retina and optic tectum neuronal connections.		These notes introduce {{vision}} development of the eye: induction and regional specification of the eye structures, maturation and formation of retina and optic tectum neuronal connections.

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	== Some Recent Findings ==		== Some Recent Findings ==
	~~[[File:Human-retina-01.jpg\|thumb\|300px\|Adult Human Retina histology{{#pmid:12186651\|PMID12186651}}]]~~
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Z8600021 at 06:14, 26 February 2022

2022-02-26T06:14:43Z

← Older revision		Revision as of 17:14, 26 February 2022
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			* '''Vision-dependent specification of cell types and function in the developing cortex'''{{#pmid:35063073\|PMID35063073}} "The role of postnatal experience in sculpting cortical circuitry, while long appreciated, is poorly understood at the level of cell types. We explore this in the mouse primary visual cortex (V1) using single-nucleus RNA sequencing, visual deprivation, genetics, and functional imaging. We find that vision selectively drives the specification of glutamatergic cell types in upper layers (L) (L2/3/4), while deeper-layer glutamatergic, GABAergic, and non-neuronal cell types are established prior to eye opening. L2/3 cell types form an experience-dependent spatial continuum defined by the graded expression of ∼200 genes, including regulators of cell adhesion and synapse formation. One of these genes, Igsf9b, a vision-dependent gene encoding an inhibitory synaptic cell adhesion molecule, is required for the normal development of binocular responses in L2/3. In summary, vision preferentially regulates the development of upper-layer glutamatergic cell types through the regulation of cell-type-specific gene expression programs."

	* '''Endocrine regulation of multichromatic color vision.'''{{#pmid:31383755\|PMID31383755}} "Vertebrate color vision requires spectrally selective opsin-based pigments, expressed in distinct cone photoreceptor populations. In primates and in fish, spectrally divergent opsin genes may reside in head-to-tail tandem arrays. Mechanisms underlying differential expression from such arrays have not been fully elucidated. Regulation of human red (LWS) vs. green (MWS) opsins is considered a stochastic event, whereby upstream enhancers associate randomly with promoters of the proximal or distal gene, and one of these associations becomes permanent. We demonstrate that, distinct from this stochastic model, the endocrine signal {{thyroid}} hormone (TH) regulates differential expression of the orthologous {{zebrafish}} lws1/lws2 array, and of the tandemly quadruplicated rh2-1/rh2-2/rh2-3/rh2-4 array. TH treatment caused dramatic, dose-dependent increases in abundance of lws1, the proximal member of the lws array, and reduced lws2 Fluorescent lws reporters permitted direct visualization of individual cones switching expression from lws2 to lws1 Athyroidism increased lws2 and reduced lws1, except within a small ventral domain of lws1 that was likely sustained by retinoic acid signaling. Changes in lws abundance and distribution in athyroid zebrafish were rescued by TH, demonstrating plasticity of cone phenotype in response to this signal. TH manipulations also regulated the rh2 array, with athyroidism reducing abundance of distal members. Interestingly, the opsins encoded by the proximal lws gene and distal rh2 genes are sensitive to longer wavelengths than other members of their respective arrays; therefore, endogenous TH acts upon each opsin array to shift overall spectral sensitivity toward longer wavelengths, underlying coordinated changes in visual system function during development and growth."		* '''Endocrine regulation of multichromatic color vision.'''{{#pmid:31383755\|PMID31383755}} "Vertebrate color vision requires spectrally selective opsin-based pigments, expressed in distinct cone photoreceptor populations. In primates and in fish, spectrally divergent opsin genes may reside in head-to-tail tandem arrays. Mechanisms underlying differential expression from such arrays have not been fully elucidated. Regulation of human red (LWS) vs. green (MWS) opsins is considered a stochastic event, whereby upstream enhancers associate randomly with promoters of the proximal or distal gene, and one of these associations becomes permanent. We demonstrate that, distinct from this stochastic model, the endocrine signal {{thyroid}} hormone (TH) regulates differential expression of the orthologous {{zebrafish}} lws1/lws2 array, and of the tandemly quadruplicated rh2-1/rh2-2/rh2-3/rh2-4 array. TH treatment caused dramatic, dose-dependent increases in abundance of lws1, the proximal member of the lws array, and reduced lws2 Fluorescent lws reporters permitted direct visualization of individual cones switching expression from lws2 to lws1 Athyroidism increased lws2 and reduced lws1, except within a small ventral domain of lws1 that was likely sustained by retinoic acid signaling. Changes in lws abundance and distribution in athyroid zebrafish were rescued by TH, demonstrating plasticity of cone phenotype in response to this signal. TH manipulations also regulated the rh2 array, with athyroidism reducing abundance of distal members. Interestingly, the opsins encoded by the proximal lws gene and distal rh2 genes are sensitive to longer wavelengths than other members of their respective arrays; therefore, endogenous TH acts upon each opsin array to shift overall spectral sensitivity toward longer wavelengths, underlying coordinated changes in visual system function during development and growth."

	* '''Fetal ocular development in the {{second trimester}} of pregnancy documented by 7.0 T postmortem Magnetic Resonance Imaging'''{{#pmid:30947240\|PMID30947240}} "Few investigators have analyzed fetal ocular growth with Magnetic Resonance Imaging (MRI) of high magnetic strength. Our purpose is to obtain normative biometrics for fetal ocular development in the second trimester of pregnancy. Sixty specimens with a gestational age (GA) of 12-23 weeks were scanned using a 7.0 T MRI scanner. The linear interocular and binocular distances (IOD and BOD, respectively), globe diameter (GD) and lens diameter (LD) were measured on the transverse section of the largest diameter of the eyeballs. The three dimensional (3D) visualization model of the eyeball was reconstructed with Amira software. Then, the globe and lens volumes (GV and LV, respectively) were obtained. All the measurements were plotted as a function of GA. The fetal ocular structures in the second trimester of pregnancy could be clearly delineated on 7.0 T postmortem MRI images. All the linear measurements logarithmically increased with GA, while, the volumetric measurements linearly increased with GA. Postmortem MRI of high magnetic strength can clearly document fetal ocular growth in the second trimester of pregnancy. These quantitative data may be a valuable reference for the assessment of normal fetal eyeball development in clinical settings and may be considered a supplement to anatomical investigations."		* '''Fetal ocular development in the {{second trimester}} of pregnancy documented by 7.0 T postmortem Magnetic Resonance Imaging'''{{#pmid:30947240\|PMID30947240}} "Few investigators have analyzed fetal ocular growth with Magnetic Resonance Imaging (MRI) of high magnetic strength. Our purpose is to obtain normative biometrics for fetal ocular development in the second trimester of pregnancy. Sixty specimens with a gestational age (GA) of 12-23 weeks were scanned using a 7.0 T MRI scanner. The linear interocular and binocular distances (IOD and BOD, respectively), globe diameter (GD) and lens diameter (LD) were measured on the transverse section of the largest diameter of the eyeballs. The three dimensional (3D) visualization model of the eyeball was reconstructed with Amira software. Then, the globe and lens volumes (GV and LV, respectively) were obtained. All the measurements were plotted as a function of GA. The fetal ocular structures in the second trimester of pregnancy could be clearly delineated on 7.0 T postmortem MRI images. All the linear measurements logarithmically increased with GA, while, the volumetric measurements linearly increased with GA. Postmortem MRI of high magnetic strength can clearly document fetal ocular growth in the second trimester of pregnancy. These quantitative data may be a valuable reference for the assessment of normal fetal eyeball development in clinical settings and may be considered a supplement to anatomical investigations."

	* '''The relationship between eye movement and vision develops before birth''' {{#pmid:22496813\|PMID22496813}} "While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30-36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth."

	* '''Activation of c-Jun N-Terminal Kinase (JNK) during Mitosis in Retinal Progenitor Cells'''{{#pmid:22496813\|PMID22496813}} "Most studies of c-Jun N-terminal Kinase (JNK) activation in retinal tissue were done in the context of neurodegeneration. In this study, we investigated the behavior of JNK during mitosis of progenitor cells in the retina of newborn rats. ... The data show, for the first time, that JNK is activated in mitotic progenitor cells of developing retinal tissue, suggesting a new role of JNK in the control of progenitor cell proliferation in the retina."

	\|}		\|}
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	\|-		\|-
	\| {{Older papers}}		\| {{Older papers}}

			* '''The relationship between eye movement and vision develops before birth''' {{#pmid:22496813\|PMID22496813}} "While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30-36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth."

			* '''Activation of c-Jun N-Terminal Kinase (JNK) during Mitosis in Retinal Progenitor Cells'''{{#pmid:22496813\|PMID22496813}} "Most studies of c-Jun N-terminal Kinase (JNK) activation in retinal tissue were done in the context of neurodegeneration. In this study, we investigated the behavior of JNK during mitosis of progenitor cells in the retina of newborn rats. ... The data show, for the first time, that JNK is activated in mitotic progenitor cells of developing retinal tissue, suggesting a new role of JNK in the control of progenitor cell proliferation in the retina."
	* '''Rearrangement of retinogeniculate projection patterns after eye-specific segregation in mice'''{{#pmid:20544023\|PMID20544023}} "When monocular enucleation was performed after eye-specific segregation, rearrangement of retinogeniculate axons in the dorsal lateral geniculate nucleus (dLGN) was observed within 5 days. ...We also examined the critical period for this rearrangement and found that the rearrangement became almost absent by the beginning of the critical period for ocular dominance plasticity in the primary visual cortex."		* '''Rearrangement of retinogeniculate projection patterns after eye-specific segregation in mice'''{{#pmid:20544023\|PMID20544023}} "When monocular enucleation was performed after eye-specific segregation, rearrangement of retinogeniculate axons in the dorsal lateral geniculate nucleus (dLGN) was observed within 5 days. ...We also examined the critical period for this rearrangement and found that the rearrangement became almost absent by the beginning of the critical period for ocular dominance plasticity in the primary visual cortex."

Z8600021 at 23:37, 19 November 2019

2019-11-19T23:37:12Z

← Older revision		Revision as of 10:37, 20 November 2019
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	* '''Endocrine regulation of multichromatic color vision.'''{{#pmid:31383755\|PMID31383755}} "Vertebrate color vision requires spectrally selective opsin-based pigments, expressed in distinct cone photoreceptor populations. In primates and in fish, spectrally divergent opsin genes may reside in head-to-tail tandem arrays. Mechanisms underlying differential expression from such arrays have not been fully elucidated. Regulation of human red (LWS) vs. green (MWS) opsins is considered a stochastic event, whereby upstream enhancers associate randomly with promoters of the proximal or distal gene, and one of these associations becomes permanent. We demonstrate that, distinct from this stochastic model, the endocrine signal {{thyroid}} hormone (TH) regulates differential expression of the orthologous {{zebrafish}} lws1/lws2 array, and of the tandemly quadruplicated rh2-1/rh2-2/rh2-3/rh2-4 array. TH treatment caused dramatic, dose-dependent increases in abundance of lws1, the proximal member of the lws array, and reduced lws2 Fluorescent lws reporters permitted direct visualization of individual cones switching expression from lws2 to lws1 Athyroidism increased lws2 and reduced lws1, except within a small ventral domain of lws1 that was likely sustained by retinoic acid signaling. Changes in lws abundance and distribution in athyroid zebrafish were rescued by TH, demonstrating plasticity of cone phenotype in response to this signal. TH manipulations also regulated the rh2 array, with athyroidism reducing abundance of distal members. Interestingly, the opsins encoded by the proximal lws gene and distal rh2 genes are sensitive to longer wavelengths than other members of their respective arrays; therefore, endogenous TH acts upon each opsin array to shift overall spectral sensitivity toward longer wavelengths, underlying coordinated changes in visual system function during development and growth."		* '''Endocrine regulation of multichromatic color vision.'''{{#pmid:31383755\|PMID31383755}} "Vertebrate color vision requires spectrally selective opsin-based pigments, expressed in distinct cone photoreceptor populations. In primates and in fish, spectrally divergent opsin genes may reside in head-to-tail tandem arrays. Mechanisms underlying differential expression from such arrays have not been fully elucidated. Regulation of human red (LWS) vs. green (MWS) opsins is considered a stochastic event, whereby upstream enhancers associate randomly with promoters of the proximal or distal gene, and one of these associations becomes permanent. We demonstrate that, distinct from this stochastic model, the endocrine signal {{thyroid}} hormone (TH) regulates differential expression of the orthologous {{zebrafish}} lws1/lws2 array, and of the tandemly quadruplicated rh2-1/rh2-2/rh2-3/rh2-4 array. TH treatment caused dramatic, dose-dependent increases in abundance of lws1, the proximal member of the lws array, and reduced lws2 Fluorescent lws reporters permitted direct visualization of individual cones switching expression from lws2 to lws1 Athyroidism increased lws2 and reduced lws1, except within a small ventral domain of lws1 that was likely sustained by retinoic acid signaling. Changes in lws abundance and distribution in athyroid zebrafish were rescued by TH, demonstrating plasticity of cone phenotype in response to this signal. TH manipulations also regulated the rh2 array, with athyroidism reducing abundance of distal members. Interestingly, the opsins encoded by the proximal lws gene and distal rh2 genes are sensitive to longer wavelengths than other members of their respective arrays; therefore, endogenous TH acts upon each opsin array to shift overall spectral sensitivity toward longer wavelengths, underlying coordinated changes in visual system function during development and growth."

			* '''Fetal ocular development in the {{second trimester}} of pregnancy documented by 7.0 T postmortem Magnetic Resonance Imaging'''{{#pmid:30947240\|PMID30947240}} "Few investigators have analyzed fetal ocular growth with Magnetic Resonance Imaging (MRI) of high magnetic strength. Our purpose is to obtain normative biometrics for fetal ocular development in the second trimester of pregnancy. Sixty specimens with a gestational age (GA) of 12-23 weeks were scanned using a 7.0 T MRI scanner. The linear interocular and binocular distances (IOD and BOD, respectively), globe diameter (GD) and lens diameter (LD) were measured on the transverse section of the largest diameter of the eyeballs. The three dimensional (3D) visualization model of the eyeball was reconstructed with Amira software. Then, the globe and lens volumes (GV and LV, respectively) were obtained. All the measurements were plotted as a function of GA. The fetal ocular structures in the second trimester of pregnancy could be clearly delineated on 7.0 T postmortem MRI images. All the linear measurements logarithmically increased with GA, while, the volumetric measurements linearly increased with GA. Postmortem MRI of high magnetic strength can clearly document fetal ocular growth in the second trimester of pregnancy. These quantitative data may be a valuable reference for the assessment of normal fetal eyeball development in clinical settings and may be considered a supplement to anatomical investigations."

	* '''The relationship between eye movement and vision develops before birth''' {{#pmid:22496813\|PMID22496813}} "While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30-36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth."		* '''The relationship between eye movement and vision develops before birth''' {{#pmid:22496813\|PMID22496813}} "While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30-36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth."

Z8600021 at 22:32, 19 November 2019

2019-11-19T22:32:17Z

← Older revision		Revision as of 09:32, 20 November 2019
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			* '''Endocrine regulation of multichromatic color vision.'''{{#pmid:31383755\|PMID31383755}} "Vertebrate color vision requires spectrally selective opsin-based pigments, expressed in distinct cone photoreceptor populations. In primates and in fish, spectrally divergent opsin genes may reside in head-to-tail tandem arrays. Mechanisms underlying differential expression from such arrays have not been fully elucidated. Regulation of human red (LWS) vs. green (MWS) opsins is considered a stochastic event, whereby upstream enhancers associate randomly with promoters of the proximal or distal gene, and one of these associations becomes permanent. We demonstrate that, distinct from this stochastic model, the endocrine signal {{thyroid}} hormone (TH) regulates differential expression of the orthologous {{zebrafish}} lws1/lws2 array, and of the tandemly quadruplicated rh2-1/rh2-2/rh2-3/rh2-4 array. TH treatment caused dramatic, dose-dependent increases in abundance of lws1, the proximal member of the lws array, and reduced lws2 Fluorescent lws reporters permitted direct visualization of individual cones switching expression from lws2 to lws1 Athyroidism increased lws2 and reduced lws1, except within a small ventral domain of lws1 that was likely sustained by retinoic acid signaling. Changes in lws abundance and distribution in athyroid zebrafish were rescued by TH, demonstrating plasticity of cone phenotype in response to this signal. TH manipulations also regulated the rh2 array, with athyroidism reducing abundance of distal members. Interestingly, the opsins encoded by the proximal lws gene and distal rh2 genes are sensitive to longer wavelengths than other members of their respective arrays; therefore, endogenous TH acts upon each opsin array to shift overall spectral sensitivity toward longer wavelengths, underlying coordinated changes in visual system function during development and growth."

	* '''The relationship between eye movement and vision develops before birth''' {{#pmid:22496813\|PMID22496813}} "While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30-36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth."		* '''The relationship between eye movement and vision develops before birth''' {{#pmid:22496813\|PMID22496813}} "While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30-36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth."

	* '''Activation of c-Jun N-Terminal Kinase (JNK) during Mitosis in Retinal Progenitor Cells'''{{#pmid:22496813\|PMID22496813}} "Most studies of c-Jun N-terminal Kinase (JNK) activation in retinal tissue were done in the context of neurodegeneration. In this study, we investigated the behavior of JNK during mitosis of progenitor cells in the retina of newborn rats. ... The data show, for the first time, that JNK is activated in mitotic progenitor cells of developing retinal tissue, suggesting a new role of JNK in the control of progenitor cell proliferation in the retina."		* '''Activation of c-Jun N-Terminal Kinase (JNK) during Mitosis in Retinal Progenitor Cells'''{{#pmid:22496813\|PMID22496813}} "Most studies of c-Jun N-terminal Kinase (JNK) activation in retinal tissue were done in the context of neurodegeneration. In this study, we investigated the behavior of JNK during mitosis of progenitor cells in the retina of newborn rats. ... The data show, for the first time, that JNK is activated in mitotic progenitor cells of developing retinal tissue, suggesting a new role of JNK in the control of progenitor cell proliferation in the retina."

	* '''Rearrangement of retinogeniculate projection patterns after eye-specific segregation in mice'''{{#pmid:20544023\|PMID20544023}} "When monocular enucleation was performed after eye-specific segregation, rearrangement of retinogeniculate axons in the dorsal lateral geniculate nucleus (dLGN) was observed within 5 days. ...We also examined the critical period for this rearrangement and found that the rearrangement became almost absent by the beginning of the critical period for ocular dominance plasticity in the primary visual cortex."

	* '''The long noncoding RNA RNCR2 directs mouse retinal cell specification'''{{#pmid:20459797\|PMID20459797}} "We find that the RNCR2 is selectively expressed in a subset of both mitotic progenitors and postmitotic retinal precursor cells. ShRNA-mediated knockdown of RNCR2 results in an increase of both amacrine cells and Müller glia, indicating a role for this lncRNA in regulating retinal cell fate specification."
	\|}		\|}
	{\| class="wikitable mw-collapsible mw-collapsed"		{\| class="wikitable mw-collapsible mw-collapsed"
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	Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Vision+Development ''Vision Development''] \| [http://www.ncbi.nlm.nih.gov/pubmed/?term=Vision+Embryology ''Vision Embryology'']		Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Vision+Development ''Vision Development''] \| [http://www.ncbi.nlm.nih.gov/pubmed/?term=Vision+Embryology ''Vision Embryology'']

			\|}
			{\| class="wikitable mw-collapsible mw-collapsed"
			! Older papers
			\|-
			\| {{Older papers}}
			* '''Rearrangement of retinogeniculate projection patterns after eye-specific segregation in mice'''{{#pmid:20544023\|PMID20544023}} "When monocular enucleation was performed after eye-specific segregation, rearrangement of retinogeniculate axons in the dorsal lateral geniculate nucleus (dLGN) was observed within 5 days. ...We also examined the critical period for this rearrangement and found that the rearrangement became almost absent by the beginning of the critical period for ocular dominance plasticity in the primary visual cortex."

			* '''The long noncoding RNA RNCR2 directs mouse retinal cell specification'''{{#pmid:20459797\|PMID20459797}} "We find that the RNCR2 is selectively expressed in a subset of both mitotic progenitors and postmitotic retinal precursor cells. ShRNA-mediated knockdown of RNCR2 results in an increase of both amacrine cells and Müller glia, indicating a role for this lncRNA in regulating retinal cell fate specification."
	\|}		\|}
	==Timeline==		==Timeline==

Z8600021 at 07:21, 2 April 2019

2019-04-02T07:21:56Z

← Older revision		Revision as of 18:21, 2 April 2019
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	These notes introduce {{vision}} development of the eye: induction and regional specification of the eye structures, maturation and formation of retina and optic tectum neuronal connections.		These notes introduce {{vision}} development of the eye: induction and regional specification of the eye structures, maturation and formation of retina and optic tectum neuronal connections.

	The adult eye has contributions from several different embryonic layers eventually forming neuronal, supportive connective tissue, optical structures, and muscular tissues.		The adult eye has contributions from several different embryonic layers eventually forming neuronal, supportive connective tissue, optical structures, and muscular tissues. Historically determined that at birth, the human eyeball volume is about 3.25 cc and the estimated weight is about 3.40 grams.<ref name=ScammonArmstrong1925>{{Ref-ScammonArmstrong1925}}</ref>

	There are additional pages shown in the vision links, covering specific topics of vision development.		There are additional pages shown in the vision links, covering specific topics of vision development.

Z8600021 at 03:49, 19 February 2019

2019-02-19T03:49:10Z

← Older revision		Revision as of 14:49, 19 February 2019
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	See below the drawings of sections of the whole eye from week 8 of development.<ref name="Streeter1957">{{Ref-Streeter1957}}</ref>		See below the drawings of sections of the whole eye from week 8 of development.<ref name="Streeter1957">{{Ref-Streeter1957}}</ref>

			Optic Nerve
			* Carnegie stage {{CS19}} - Optic nerve small, slender. Lumen practically whole length of stalk. Few or no fibers.
			* Carnegie stage {{CS20}} - Ependymal arrangement partially retained along stalk. Remnant of ependyma along whole length of stalk. Hyaloid groove at bulbar end. A few fibers arriving at brain.
			* Carnegie stage {{CS21}} - Remnant of ependyma present.
			* Carnegie stage {{CS22}} - Sheath layer beginning to form. Vascular canal present.
			* Carnegie stage {{CS23}} - Early nerve sheath. Reticular spongioblastic framework, striate arrangement of nuclei, bundles of fibers. Definite nerve sheath.

	<gallery caption="Eye and Optic Nerve">		<gallery caption="Eye and Optic Nerve">
	File:Streeter1957 fig04-19.jpg\|[[Carnegie stage ~~19]]~~		File:Streeter1957 fig04-19.jpg\|Carnegie stage {{CS19}}
	File:Streeter1957 fig04-20.jpg\|[[Carnegie stage ~~20]]~~		File:Streeter1957 fig04-20.jpg\|Carnegie stage {{CS20}}
	File:Streeter1957 fig04-21.jpg\|[[Carnegie stage ~~21]]~~		File:Streeter1957 fig04-21.jpg\|Carnegie stage {{CS21}}
	File:Streeter1957 fig04-22.jpg\|[[Carnegie stage ~~22]]~~		File:Streeter1957 fig04-22.jpg\|Carnegie stage {{CS22}}
	File:Streeter1957 fig04-23.jpg\|[[Carnegie stage ~~23]]~~		File:Streeter1957 fig04-23.jpg\|Carnegie stage {{CS23}}
	</gallery>		</gallery>

	==Lens==		==Lens==
	[[File:Stage_22_image_155.jpg\|thumb\|Human Lens (stage 22)]]		[[File:Stage_22_image_155.jpg\|thumb\|Human Lens (Carnegie stage {{CS222}})]]
	The lens or crystalline lens or aquula (Latin, aquula = a little stream) has a key role in focussing light (with the cornea) upon the neural retina. The lens embryonic origin is from surface ectoderm of the sensory placodes that form in the head region (More? Week 4 - Placodes). The lens focusses by refracting light as it passes through the biconvex lens, which can be altered in shape (accommodation) by surrounding ciliary muscles. These ciliary muscles are activated (contracted) by parasympathetic innervation from the ciliary ganglion itself innervated by the oculomotor nerve (Cranial Nerve III) (More? Cranial Nerves).		The lens or crystalline lens or aquula (Latin, aquula = a little stream) has a key role in focussing light (with the cornea) upon the neural retina. The lens embryonic origin is from surface ectoderm of the sensory placodes that form in the head region (More? Week 4 - Placodes). The lens focusses by refracting light as it passes through the biconvex lens, which can be altered in shape (accommodation) by surrounding ciliary muscles. These ciliary muscles are activated (contracted) by parasympathetic innervation from the ciliary ganglion itself innervated by the oculomotor nerve (Cranial Nerve III) (More? Cranial Nerves).

Z8600021 at 03:36, 19 February 2019

2019-02-19T03:36:21Z

← Older revision		Revision as of 14:36, 19 February 2019
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	\| [[File:Mark_Hill.jpg\|90px\|left]] {{Most_Recent_Refs}}		\| [[File:Mark_Hill.jpg\|90px\|left]] {{Most_Recent_Refs}}

	Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Vision+Development ''Vision Development'']		Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Vision+Development ''Vision Development''] \| [http://www.ncbi.nlm.nih.gov/pubmed/?term=Vision+Embryology ''Vision Embryology'']

	~~<pubmed limit=5>Vision Development</pubmed>~~

	~~Search term: [http://www.ncbi.nlm.nih.gov/pubmed/?term=Vision+Embryology ''Vision Embryology'']~~

	~~<pubmed limit=5>Vision Embryology</pubmed>~~
	\|}		\|}
	==Timeline==		==Timeline==

Z8600021 at 01:11, 6 Mayıs 2018

2018-05-06T01:11:29Z

← Older revision		Revision as of 12:11, 6 Mayıs 2018
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	{{Vision Links}}		{{Vision Links}}
			<br>

	{{Senses Links}}		{{Senses Links}}

Z8600021 at 21:49, 16 April 2018

2018-04-16T21:49:00Z

← Older revision		Revision as of 08:49, 17 April 2018
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	==Introduction==		==Introduction==
	[[File:Historic_retina_drawing.jpg\|right\|300px]]		[[File:Historic_retina_drawing.jpg\|right\|300px]]
	These notes introduce ~~the~~ development of the eye: induction and regional specification of the eye structures, maturation and formation of retina and optic tectum neuronal connections.		These notes introduce {{vision}} development of the eye: induction and regional specification of the eye structures, maturation and formation of retina and optic tectum neuronal connections.

	The adult eye has contributions from several different embryonic layers eventually forming neuronal, supportive connective tissue, optical structures, and muscular tissues.		The adult eye has contributions from several different embryonic layers eventually forming neuronal, supportive connective tissue, optical structures, and muscular tissues.

← Older revision		Revision as of 10:37, 20 November 2019
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	* '''Endocrine regulation of multichromatic color vision.'''{{#pmid:31383755\|PMID31383755}} "Vertebrate color vision requires spectrally selective opsin-based pigments, expressed in distinct cone photoreceptor populations. In primates and in fish, spectrally divergent opsin genes may reside in head-to-tail tandem arrays. Mechanisms underlying differential expression from such arrays have not been fully elucidated. Regulation of human red (LWS) vs. green (MWS) opsins is considered a stochastic event, whereby upstream enhancers associate randomly with promoters of the proximal or distal gene, and one of these associations becomes permanent. We demonstrate that, distinct from this stochastic model, the endocrine signal {{thyroid}} hormone (TH) regulates differential expression of the orthologous {{zebrafish}} lws1/lws2 array, and of the tandemly quadruplicated rh2-1/rh2-2/rh2-3/rh2-4 array. TH treatment caused dramatic, dose-dependent increases in abundance of lws1, the proximal member of the lws array, and reduced lws2 Fluorescent lws reporters permitted direct visualization of individual cones switching expression from lws2 to lws1 Athyroidism increased lws2 and reduced lws1, except within a small ventral domain of lws1 that was likely sustained by retinoic acid signaling. Changes in lws abundance and distribution in athyroid zebrafish were rescued by TH, demonstrating plasticity of cone phenotype in response to this signal. TH manipulations also regulated the rh2 array, with athyroidism reducing abundance of distal members. Interestingly, the opsins encoded by the proximal lws gene and distal rh2 genes are sensitive to longer wavelengths than other members of their respective arrays; therefore, endogenous TH acts upon each opsin array to shift overall spectral sensitivity toward longer wavelengths, underlying coordinated changes in visual system function during development and growth."		* '''Endocrine regulation of multichromatic color vision.'''{{#pmid:31383755\|PMID31383755}} "Vertebrate color vision requires spectrally selective opsin-based pigments, expressed in distinct cone photoreceptor populations. In primates and in fish, spectrally divergent opsin genes may reside in head-to-tail tandem arrays. Mechanisms underlying differential expression from such arrays have not been fully elucidated. Regulation of human red (LWS) vs. green (MWS) opsins is considered a stochastic event, whereby upstream enhancers associate randomly with promoters of the proximal or distal gene, and one of these associations becomes permanent. We demonstrate that, distinct from this stochastic model, the endocrine signal {{thyroid}} hormone (TH) regulates differential expression of the orthologous {{zebrafish}} lws1/lws2 array, and of the tandemly quadruplicated rh2-1/rh2-2/rh2-3/rh2-4 array. TH treatment caused dramatic, dose-dependent increases in abundance of lws1, the proximal member of the lws array, and reduced lws2 Fluorescent lws reporters permitted direct visualization of individual cones switching expression from lws2 to lws1 Athyroidism increased lws2 and reduced lws1, except within a small ventral domain of lws1 that was likely sustained by retinoic acid signaling. Changes in lws abundance and distribution in athyroid zebrafish were rescued by TH, demonstrating plasticity of cone phenotype in response to this signal. TH manipulations also regulated the rh2 array, with athyroidism reducing abundance of distal members. Interestingly, the opsins encoded by the proximal lws gene and distal rh2 genes are sensitive to longer wavelengths than other members of their respective arrays; therefore, endogenous TH acts upon each opsin array to shift overall spectral sensitivity toward longer wavelengths, underlying coordinated changes in visual system function during development and growth."

			* '''Fetal ocular development in the {{second trimester}} of pregnancy documented by 7.0 T postmortem Magnetic Resonance Imaging'''{{#pmid:30947240\|PMID30947240}} "Few investigators have analyzed fetal ocular growth with Magnetic Resonance Imaging (MRI) of high magnetic strength. Our purpose is to obtain normative biometrics for fetal ocular development in the second trimester of pregnancy. Sixty specimens with a gestational age (GA) of 12-23 weeks were scanned using a 7.0 T MRI scanner. The linear interocular and binocular distances (IOD and BOD, respectively), globe diameter (GD) and lens diameter (LD) were measured on the transverse section of the largest diameter of the eyeballs. The three dimensional (3D) visualization model of the eyeball was reconstructed with Amira software. Then, the globe and lens volumes (GV and LV, respectively) were obtained. All the measurements were plotted as a function of GA. The fetal ocular structures in the second trimester of pregnancy could be clearly delineated on 7.0 T postmortem MRI images. All the linear measurements logarithmically increased with GA, while, the volumetric measurements linearly increased with GA. Postmortem MRI of high magnetic strength can clearly document fetal ocular growth in the second trimester of pregnancy. These quantitative data may be a valuable reference for the assessment of normal fetal eyeball development in clinical settings and may be considered a supplement to anatomical investigations."

	* '''The relationship between eye movement and vision develops before birth''' {{#pmid:22496813\|PMID22496813}} "While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30-36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth."		* '''The relationship between eye movement and vision develops before birth''' {{#pmid:22496813\|PMID22496813}} "While the visuomotor system is known to develop rapidly after birth, studies have observed spontaneous activity in vertebrates in visually excitable cortical areas already before extrinsic stimuli are present. Resting state networks and fetal eye movements were observed independently in utero, but no functional brain activity coupled with visual stimuli could be detected using fetal fMRI. This study closes this gap and links in utero eye movement with corresponding functional networks. BOLD resting-state fMRI data were acquired from seven singleton fetuses between gestational weeks 30-36 with normal brain development. During the scan time, fetal eye movements were detected and tracked in the functional MRI data. We show that already in utero spontaneous fetal eye movements are linked to simultaneous networks in visual- and frontal cerebral areas. In our small but in terms of gestational age homogenous sample, evidence across the population suggests that the preparation of the human visuomotor system links visual and motor areas already prior to birth."