Sensory - Touch Development: Difference between revisions
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* '''Embryonic maturation of epidermal Merkel cells is controlled by a redundant transcription factor network'''<refname= PMID25468937><pubmed>25468937</pubmed></ref> Merkel cell-neurite complexes are located in touch-sensitive areas of the mammalian skin and are involved in recognition of the texture and shape of objects. Merkel cells are essential for these tactile discriminations, as they generate action potentials in response to touch stimuli and induce the firing of innervating afferent nerves. It has been shown that Merkel cells originate from epidermal stem cells, but the cellular and molecular mechanisms of their development are largely unknown. In this study, we analyzed Merkel cell differentiation during development and found that it is a temporally regulated maturation process characterized by a sequential activation of Merkel cell-specific genes. We uncovered key transcription factors controlling this process and showed that the transcription factor Atoh1 is required for initial Merkel cell specification. The subsequent maturation steps of Merkel cell differentiation are controlled by cooperative function of the transcription factors Sox2 and Isl1, which physically interact and work to sustain Atoh1 expression. These findings reveal the presence of a robust transcriptional network required to produce functional Merkel cells that are required for tactile discrimination." | |||
* '''Wetness perception across body sites'''<ref><pubmed>22710006</pubmed></ref> "Human skin is innervated with a variety of receptors serving somatosensation and includes the sensory sub-modalities of touch, temperature, pain and itch. The density and type of receptors differ across the body surface, and there are various body-map representations in the brain. The perceptions of skin sensations outside of the specified sub-modalities, e.g. wetness or greasiness, are described as 'touch blends' and are learned. ...The perception of wetness is generated from the coincident activation of tactile and thermal receptors. The perception of wetness did not, however, differ significantly across body sites and there were no significant interactions between wetness level and body site." | * '''Wetness perception across body sites'''<ref><pubmed>22710006</pubmed></ref> "Human skin is innervated with a variety of receptors serving somatosensation and includes the sensory sub-modalities of touch, temperature, pain and itch. The density and type of receptors differ across the body surface, and there are various body-map representations in the brain. The perceptions of skin sensations outside of the specified sub-modalities, e.g. wetness or greasiness, are described as 'touch blends' and are learned. ...The perception of wetness is generated from the coincident activation of tactile and thermal receptors. The perception of wetness did not, however, differ significantly across body sites and there were no significant interactions between wetness level and body site." | ||
* '''A Shift in Sensory Processing that Enables the Developing Human Brain to Discriminate Touch from Pain'''<ref><pubmed>21906948</pubmed></ref> "When and how infants begin to discriminate noxious from innocuous stimuli is a fundamental question in neuroscience. However, little is known about the development of the necessary cortical somatosensory functional prerequisites in the intact human brain. ... The results suggest that specific neural circuits necessary for discrimination between touch and nociception emerge from 35-37 weeks gestation in the human brain." | * '''A Shift in Sensory Processing that Enables the Developing Human Brain to Discriminate Touch from Pain'''<ref><pubmed>21906948</pubmed></ref> "When and how infants begin to discriminate noxious from innocuous stimuli is a fundamental question in neuroscience. However, little is known about the development of the necessary cortical somatosensory functional prerequisites in the intact human brain. ... The results suggest that specific neural circuits necessary for discrimination between touch and nociception emerge from 35-37 weeks gestation in the human brain." | ||
*''' Identification of epidermal progenitors for the Merkel cell lineage'''<ref><pubmed>21041368</pubmed></ref> "Epithelial stem cells in adult mammalian skin are known to maintain epidermal, follicular and sebaceous lineages during homeostasis. Recently, Merkel cell mechanoreceptors were identified as a fourth lineage derived from the proliferative layer of murine skin epithelium; however, the location of the stem or progenitor population for Merkel cells remains unknown. Here, we have identified a previously undescribed population of epidermal progenitors that reside in the touch domes of hairy skin, termed touch dome progenitor cells (TDPCs)." | *''' Identification of epidermal progenitors for the Merkel cell lineage'''<ref><pubmed>21041368</pubmed></ref> "Epithelial stem cells in adult mammalian skin are known to maintain epidermal, follicular and sebaceous lineages during homeostasis. Recently, Merkel cell mechanoreceptors were identified as a fourth lineage derived from the proliferative layer of murine skin epithelium; however, the location of the stem or progenitor population for Merkel cells remains unknown. Here, we have identified a previously undescribed population of epidermal progenitors that reside in the touch domes of hairy skin, termed touch dome progenitor cells (TDPCs)." | ||
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Revision as of 18:12, 16 December 2014
Embryology - 3 Jun 2024 Expand to Translate |
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Introduction
These notes introduce the development of the sense of touch, part of the somatosensory system. Because of the distribution of the sensory structures within the skin, this topic is generally also covered in integumentary development.
Senses Links: Introduction | placode | Hearing and Balance hearing | balance | vision | smell | taste | touch | Stage 22 | Category:Sensory |
Some Recent Findings
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More recent papers |
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This table allows an automated computer search of the external PubMed database using the listed "Search term" text link.
More? References | Discussion Page | Journal Searches | 2019 References | 2020 References Search term: Touch Development <pubmed limit=5>Touch Development</pubmed> |
Touch Receptors
Touch receptors in mammalian skin and the neural encoding of reception.[5]
Touch Pathway
Pacinian corpuscle
Meissner's corpuscle
Meissner's corpuscles are located throughout the skin and are seen concentrated in regions of high touch (finger tips, lips, genital regions).
Merkel cell
Isolated Merkel cell (em) |
Merkel cell (Merkel-Ranvier cell) integumentary (skin) receptor cell connected with somatosensory afferents.
Cell characteristics a polylobulated nucleus and numerous typical dense-core granules in a clear cytoplasm. Scale bar 5 µm (Stain - Osmium) |
Sensory Modalities
Thermoreceptors
- Receptors for heat (warmth) and cold (chill) detection.
- heat - C-fibres
- cold - Aδ fibres
Nociceptors
- Receptors for encoding and processing noxious stimuli.
- A-δ nociceptors
- Polymodal C-nociceptors
- C- mechano-insensitive nociceptors
Abnormalities
Merkel cell carcinoma
References
- ↑ <pubmed>20956378</pubmed>| PMC2958478 | JCB
- ↑ <pubmed>22710006</pubmed>
- ↑ <pubmed>21906948</pubmed>
- ↑ <pubmed>21041368</pubmed>
- ↑ <pubmed>20956378</pubmed>| PMC2958478 | JCB
Reviews
<pubmed>21841076</pubmed> <pubmed>20956378</pubmed>| JCB
Articles
Books
Neurobiology of Sensation and Reward. Gottfried JA, editor. Boca Raton (FL): CRC Press; 2011. Chapter 7 - Touch PMID 22593916
Search PubMed
Search Pubmed: Touch Development | touch receptors |
External Links
External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.
Terms
- Georg Meissner - (1829-1905) German histologist, physiologist and anatomist. Beiträge zur Anatomie und Physiologie der Haut. (Contributions to the anatomy and physiology of the skin.) Leipzig, 1853.
- Filippo Pacini - (1812-1883) Italian anatomist, published in 1840, and the name "Pacini's corpuscles" was proposed in 1844 by Henle and also by Kölliker.
Glossary Links
- Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link
Cite this page: Hill, M.A. (2024, June 3) Embryology Sensory - Touch Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Sensory_-_Touch_Development
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G