2018 Group Project 1 - Revision history

Z8600021: Protected "2018 Group Project 1" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite))

2018-10-17T05:05:28Z

Protected "2018 Group Project 1" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite))

← Older revision	Revision as of 16:05, 17 October 2018
(No difference)

Z5091101: /* History */

2018-10-17T00:05:56Z

History

← Older revision		Revision as of 11:05, 17 October 2018
Line 15:		Line 15:
	[[File:Wilhelm_His_History_Wilhelm.jpeg\|left\|230px\|thumb\|Wilhelm His]]		[[File:Wilhelm_His_History_Wilhelm.jpeg\|left\|230px\|thumb\|Wilhelm His]]
	[[File:NC Location.jpg\|right\|450px\|thumb\|The neural crest]]		[[File:NC Location.jpg\|right\|450px\|thumb\|The neural crest]]
	The "neural crest" is a structure in the embryo and is the junction between the neural and epidermal ectoderm. It is exclusive to vertebrates and forms a range of structures{{#pmid:22230617\|PMID22230617}}. The neural crest contributes a large number of cells of varying structure and function that directly or indirectly contribute to the development of tissues and organs within the body {{#pmid:19179766\|PMID19179766}}. In 1868, the neural crest cells were first identified in a chick embryo as a collection of cells known as "Zwischenstrang" by Professor Wilhelm His {{#pmid:22820859\|PMID22820859}}. Wilhelm His was among the first to provide an explanation for the mechanics governing the developing embryo as well as the physiology and the organs that the differing germinal regions would eventually give rise to {{#pmid:19179766\|PMID19179766}} This was due to his work in creating one of the first microtomes, a device that enables thin slicing of tissue~~. This~~ enabled him to see embryonic tissues at greater magnifications and resolutions ~~and~~ gave the neural crest the name, the ganglionic crest {{#pmid:26970616\|PMID26970616}}. In 1878, the term neural ridge was used to describe this collection of cells but the term neural crest was later coined by Arthur Milnes Marshall in 1879 in a paper he worked on disseminating the knowledge from his research on the development of cranial nerves in chicken embryos. {{#pmid:19179766\|PMID19179766}}.		The "neural crest" is a structure in the embryo and is the junction between the neural and epidermal ectoderm. It is exclusive to vertebrates and forms a range of structures{{#pmid:22230617\|PMID22230617}}. The neural crest contributes a large number of cells of varying structure and function that directly or indirectly contribute to the development of tissues and organs within the body {{#pmid:19179766\|PMID19179766}}. In 1868, the neural crest cells were first identified in a chick embryo as a collection of cells known as "Zwischenstrang" by Professor Wilhelm His {{#pmid:22820859\|PMID22820859}}. Wilhelm His was among the first to provide an explanation for the mechanics governing the developing embryo as well as the physiology and the organs that the differing germinal regions would eventually give rise to {{#pmid:19179766\|PMID19179766}}. This was due to his work in creating one of the first microtomes, a device that enables thin slicing of tissue, which enabled him to see embryonic tissues at greater magnifications and resolutions. He gave the neural crest the name, the ganglionic crest {{#pmid:26970616\|PMID26970616}}. In 1878, the term neural ridge was used to describe this collection of cells but the term neural crest was later coined by Arthur Milnes Marshall in 1879 in a paper he worked on disseminating the knowledge from his research on the development of cranial nerves in chicken embryos. {{#pmid:19179766\|PMID19179766}}.

	'''1890s-1950s'''		'''1890s-1950s'''

Z5113627: /* Related Anatomy */

2018-10-16T13:04:50Z

Related Anatomy

← Older revision		Revision as of 00:04, 17 October 2018
Line 86:		Line 86:
	The tissue and organ structure of the adrenal medulla should be understood with regard to its specialised function within the sympathetic nervous system.		The tissue and organ structure of the adrenal medulla should be understood with regard to its specialised function within the sympathetic nervous system.

	The medullary region of the adrenal glands is tasked with the endocrine secretions of ~~adrenaline~~ and ~~nor-adrenaline~~ in response to environmental stressors that are signalled for by the sympathetic nervous system. That is, the secretion of fight-or-flight response hormones in order to restrict vasculature to the trunk and increase vascular activity in the peripheral musculature.		The medullary region of the adrenal glands is tasked with the endocrine secretions of epinephrine and norepinephrine in response to environmental stressors that are signalled for by the sympathetic nervous system. That is, the secretion of fight-or-flight response hormones in order to restrict vasculature to the trunk and increase vascular activity in the peripheral musculature.

	The adrenal glands are supplied by several branches of the great vessels in the abdominal cavity. The secreted catecholamines in the medulla are directly able to pass to the blood stream this way.		The adrenal glands and its medulla are supplied by several branches of the great vessels in the abdominal cavity. The secreted catecholamines in the medulla are directly able to pass to the blood stream this way with a rich surface area.

	~~These~~ adrenal glands and their contents are retroperitoneal in the adult and varied in shape, with the left often being semilunar and right being pyramidal. Nervous supply of the adrenal glands is achieved by contributions from the splanchnic nerves of the celiac plexus. {{#pmid:11215683\|PMID11215683}}		The adrenal glands and their contents are retroperitoneal in the adult and varied in shape, with the left often being semilunar and right being pyramidal. Nervous supply of the adrenal glands is achieved by contributions from the splanchnic nerves of the celiac plexus. {{#pmid:11215683\|PMID11215683}}

	[[File:Dd.jpg\|400px\|thumb\|right\|Adult Adrenal Glands in situ]]		[[File:Dd.jpg\|400px\|thumb\|right\|Adult Adrenal Glands in situ]]
	----		----

	====Role of the Adrenal Medulla====		====Role of the Adrenal Medulla====

Z5113627: /* Genes and Transcription Factors Involved with the Adrenal Medulla's Development */

2018-10-16T11:48:54Z

Genes and Transcription Factors Involved with the Adrenal Medulla's Development

← Older revision		Revision as of 22:48, 16 October 2018
Line 132:		Line 132:
	[[File:Catecholamine_Synthesis.jpg\|400px\|thumb\|right\|Biochemical Cascade of Catecholamine Synthesis]]		[[File:Catecholamine_Synthesis.jpg\|400px\|thumb\|right\|Biochemical Cascade of Catecholamine Synthesis]]

	The importance of Somitogenesis and Neural Crest come to a head when neural crest cells must migrate anteriorly past somites 18 to 24		The importance of Somitogenesis and Neural Crest come to a head when neural crest cells must migrate anteriorly past somites 18 to 24, utilising chemoattraction from cells of the extracellular matrix between the neural tube and Adrenal Cortex's primordial mesoderm

	Members of the SOX gene family have multiple key contributors to Neural Crest in the Adrenal Medulla.		Members of the SOX gene family have multiple key contributors to Neural Crest in the Adrenal Medulla.


	Mouse models have demonstrated that SOX-10 knock-outs (mice whose DNA has been engineered to not express SOX-10) do not have an adrenal medulla. There has also been suggestion that SOX-8,9 and 10 are all strongly related to the migratory patterning of neural crest cells to the developing adrenal glands. {{#pmid:18272785\|PMID18272785}}		Mouse models have demonstrated that SOX-10 knock-outs (mice whose DNA has been engineered to not express SOX-10) do not have an adrenal medulla. There has also been suggestion that SOX-8,9 and 10 are all strongly related to the migratory patterning of neural crest cells to the developing adrenal glands. {{#pmid:18272785\|PMID18272785}}

Z5091101: /* History */

2018-10-16T11:25:42Z

History

← Older revision		Revision as of 22:25, 16 October 2018
Line 31:		Line 31:
	[[File:Regions_of_NC_Cells.jpg\|left\|Neural crest regions\|thumb\|465px]]		[[File:Regions_of_NC_Cells.jpg\|left\|Neural crest regions\|thumb\|465px]]
	From the 1980s-1990s, the causative agent of organ transformation from one to another (homeotic patterning), as well as the Hox genes which regulate the axis of most symmetrical animal embryos were founded and studied. The neural crest, which previously was divided into the cranial and trunk regions, was now further divided into the vagal and sacral neural crest, the cardiac neural crest and the cephalic neural crest {{#pmid:19179766\|PMID19179766}}. The vagal & sacral neural crest gives rise to the parasympathetic ganglia found in the gut. Without these ganglia, peristalsis, is not possible <ref name=Gilbert2000>Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. The Neural Crest. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10065/</ref>. The cardiac neural crest contributes to the valves, septa and major blood vessels of the heart, as well as connective tissues and cartilage{{#pmid:19179766\|PMID19179766}}. This is important for the structure of the heart as well as its overall function, enabling it to move blood around the body efficiently as well as keep pulmonary and aortic circulation separated <ref name=Gilbert2000>Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. The Neural Crest. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10065/</ref>.		From the 1980s-1990s, the causative agent of organ transformation from one to another (homeotic patterning), as well as the Hox genes which regulate the axis of most symmetrical animal embryos were founded and studied. The neural crest, which previously was divided into the cranial and trunk regions, was now further divided into the vagal and sacral neural crest, the cardiac neural crest and the cephalic neural crest {{#pmid:19179766\|PMID19179766}}. The vagal & sacral neural crest gives rise to the parasympathetic ganglia found in the gut. Without these ganglia, peristalsis, is not possible <ref name=Gilbert2000>Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. The Neural Crest. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10065/</ref>. The cardiac neural crest contributes to the valves, septa and major blood vessels of the heart, as well as connective tissues and cartilage{{#pmid:19179766\|PMID19179766}}. This is important for the structure of the heart as well as its overall function, enabling it to move blood around the body efficiently as well as keep pulmonary and aortic circulation separated <ref name=Gilbert2000>Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. The Neural Crest. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10065/</ref>.

			In the mid 1980s, the first studies bringing about some information on the destination of ventrally migrating neural crest cells were conducted using the antibody HNK-1, as it is known to detect antigens on neuroectodermal cells & label the migratory cells. Where previously it was thought that trunk neural crest cells migrated whilst avoiding the somites, these studies showed that the trunk neural crest cells migrated through the rostral half of each somite. How this worked was eventually understood as a result of chemotactic factors that attract and repel the cells to follow this migration {{#pmid:26970616\|PMID26970616}}.


	Today, knowledge of the neural crest cells, their migration patterns, modes of differentiation, derivatives and apoptosis (cell death) are being studied extensively. This is being done on a comparative basis between different organisms, to add further evidence for evolution {{#pmid:19179766\|PMID19179766}}. The neural crest is definitely forging a "crest" between the fields of developmental and evolutionary biology, as it is a structure '''shared exclusively by all vertebrates'''. Invertebrates do not derive their specialised cells from the neural crest as they do not have one, rather, they derive these from the endomesoderm {{#pmid:22230617\|PMID22230617}}.		Today, knowledge of the neural crest cells, their migration patterns, modes of differentiation, derivatives and apoptosis (cell death) are being studied extensively. This is being done on a comparative basis between different organisms, to add further evidence for evolution {{#pmid:19179766\|PMID19179766}}. The neural crest is definitely forging a "crest" between the fields of developmental and evolutionary biology, as it is a structure '''shared exclusively by all vertebrates'''. Invertebrates do not derive their specialised cells from the neural crest as they do not have one, rather, they derive these from the endomesoderm {{#pmid:22230617\|PMID22230617}}.


	'''Future directions'''		'''Future directions'''

	Since its discovery by His, the neural crest field has made great progress, from studies performed on the structure, to analysis of the molecules and whether certain aspects of the neural crest are specific to a single species of organism, or to all vertebrates collectively. Future work on the cranial neural crest needs to be done as well as identifying and categorising the networks responsible for the proliferation and death of cells, as well as how the cells move and migrate, as well as the gene regulatory networks (GRNs) that regulate the synthesis of proteins. Advances in technology will undeniably lead us to more answers on the subject {{#pmid:~~22230617~~\|~~PMID22230617~~}}.		Since its discovery by His, the neural crest field has made great progress, from studies performed on the structure, to analysis of the molecules and whether certain aspects of the neural crest are specific to a single species of organism, or to all vertebrates collectively. Future work on the cranial neural crest needs to be done as well as identifying and categorising the networks responsible for the proliferation and death of cells, as well as how the cells move and migrate, as well as the gene regulatory networks (GRNs) that regulate the synthesis of proteins {{#pmid:22230617\|PMID22230617}}.
			. Advances in technology will undeniably lead us to more answers on the subject and studies that include imaging, mathematical and molecular modelling will greatly enhance our growing understanding of how neural crest cells move {{#pmid:26970616\|PMID26970616}}.

	===Developmental time course===		===Developmental time course===

Z5112688: /* Glossary */

2018-10-16T08:13:37Z

Glossary

← Older revision		Revision as of 19:13, 16 October 2018
Line 205:		Line 205:
	*PCC - Pheochromocytoma		*PCC - Pheochromocytoma
	*PGL - Pheochromocytoma Paraganglioma		*PGL - Pheochromocytoma Paraganglioma
			*PNMT - phenylethanolamine-N-methyltransferase
	*SGC - Small Granule Containing cells		*SGC - Small Granule Containing cells
	*SOX - Sry Box		*SOX - Sry Box

Z5112688: /* Chicken models */

2018-10-16T08:12:12Z

Chicken models

← Older revision		Revision as of 19:12, 16 October 2018
Line 170:		Line 170:

	=====Chicken models=====		=====Chicken models=====
	Chicken and rat models are often the most commonly used models when dealing with neural crest cells. ~~In this particular~~ review, collates multiple researchers results and presents evidence to discuss previous information suggesting that sympathetic neurons and chromaffin cells do not share a common progenitor{{#pmid:3693940\|PMID3693940}}. The relevant study involved the use of cell cultures, Sympathoadrneal (SA) progenitor cells from embryonic(from chick embryos) and eary developmental stages were able to be procured. From these cultures it was easy to identify that glucocorticoids were crucial in the differentiation of SA cells into their derivatives, sympathetic neurons and chromaffin cells.		Chicken and rat models are often the most commonly used models when dealing with neural crest cells. A particle review article, collates multiple researchers results and presents evidence to discuss previous information suggesting that sympathetic neurons and chromaffin cells do not share a common progenitor{{#pmid:3693940\|PMID3693940}}. The relevant study involved the use of cell cultures, Sympathoadrneal (SA) progenitor cells from embryonic(from chick embryos) and eary developmental stages were able to be procured. From these cultures it was easy to identify that glucocorticoids were crucial in the differentiation of SA cells into their derivatives, sympathetic neurons and chromaffin cells.

	[[File:Expression of BMP protein 4 .jpg\|300px\|thumb\|right\|Shows the movement of the chromaffin progenitors moving from each stage of development. sg: sympathetic ganglia ac:adrenal cortical region ag: adrenal gland da: dorsal aortic region]]		[[File:Expression of BMP protein 4 .jpg\|300px\|thumb\|right\|Shows the movement of the chromaffin progenitors moving from each stage of development. sg: sympathetic ganglia ac:adrenal cortical region ag: adrenal gland da: dorsal aortic region]]

Z5112688: /* Current research (labs) */

2018-10-16T08:11:29Z

Current research (labs)

← Older revision		Revision as of 19:11, 16 October 2018
Line 182:		Line 182:

	As explained above the adrenal medulla plays an important part in the autonomic system of an adult human. The chromaffin cells, in particular, are important neural crest derived cell that is closely related to the adrenal medulla. Previous findings have focused specifically on the mechanisms controlling the neural crest cell migration and how these cells go on to form the different derivatives in their particular destinations in the embryo. For example, as previously explained studies have shown that chromaffin cells have been observed to move to the adrenal gland to form the medulla of the adrenal gland. This report goes through a recent study that involves the adrenal medullary cells, in particular chromaffin cells, and their potential to be used to model certain pathological diseases related to these cells. This is part of a study that also involves neural crest cells and their ability to differentiate into multiple different types of cells<ref>Lumb, R., & Schwarz, Q. (2015). Sympathoadrenal neural crest cells: The known, unknown and forgotten?. Development, Growth & Differentiation, 57(2), 146-157. doi: 10.1111/dgd.12189</ref>. Neural crest cells and SAPs from human embryonic cells and induced pluripotent stem cells were generated to be used in the experiment. By exposing the pluripotent stem cells to BMP4 in vitro, results showed that these cells would 'upregulate' the chromaffin cell - specific marker PMNT (an enzyme that synthesizes adrenaline). Furthermore when the cells from human embryos were implanted into avian embryos, there was a visible potential for the human cells to differentiate into cells that expressed the chromaffin cell markers{{#pmid:5768882\|PMID5768882}}.		As explained above the adrenal medulla plays an important part in the autonomic system of an adult human. The chromaffin cells, in particular, are important neural crest derived cell that is closely related to the adrenal medulla. Previous findings have focused specifically on the mechanisms controlling the neural crest cell migration and how these cells go on to form the different derivatives in their particular destinations in the embryo. For example, as previously explained studies have shown that chromaffin cells have been observed to move to the adrenal gland to form the medulla of the adrenal gland. This report goes through a recent study that involves the adrenal medullary cells, in particular chromaffin cells, and their potential to be used to model certain pathological diseases related to these cells. This is part of a study that also involves neural crest cells and their ability to differentiate into multiple different types of cells<ref>Lumb, R., & Schwarz, Q. (2015). Sympathoadrenal neural crest cells: The known, unknown and forgotten?. Development, Growth & Differentiation, 57(2), 146-157. doi: 10.1111/dgd.12189</ref>. Neural crest cells and SAPs from human embryonic cells and induced pluripotent stem cells were generated to be used in the experiment. By exposing the pluripotent stem cells to BMP4 in vitro, results showed that these cells would 'upregulate' the chromaffin cell - specific marker PMNT (an enzyme that synthesizes adrenaline). Furthermore when the cells from human embryos were implanted into avian embryos, there was a visible potential for the human cells to differentiate into cells that expressed the chromaffin cell markers{{#pmid:5768882\|PMID5768882}}.

			Link to article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5768882/

	====Multipotent Peripheral Glial Cells Generate Neuroendocrine Cells of the Adrenal Medulla====		====Multipotent Peripheral Glial Cells Generate Neuroendocrine Cells of the Adrenal Medulla====
Line 187:		Line 189:
	Similar to the first study, this one also focuses on the chromaffin cells and their relationship to the adrenal medulla. Chromaffin cells often represent the main endocrine component that is believed to differentiate from neural crest cells{{#pmid:28684471\|PMID28684471}}. The study focuses specifically on the idea that previous research has suggested that nerve - associated schwann cell precursor is a progenitor of chromaffin cells. What the findings suggested was that peripheral nerves provided migration routes for the progenitors. This is backed up by the results, a high concentration of chromaffin cells can be found being derived from the nerve, as nerve ablated mice in the experiment showed a large difference of 78% less cells compared to the control. Other than this, the study also brought to light the proliferative potential of the cells from nerves, with different other cell types being discovered as well (including cells such as parasympathetic{{#pmid:24925912\|PMID24925912}} and melanocytes {{#pmid:19837037 \|PMID19837037}}). The findings would provide useful information into further understanding the adrenal gland and its embryonic origins (as there is still much to learn regarding the formation of the adrenal medulla) but also pathological diseases such as neuroblastoma and pheochromatocytoma which are most common in the adrenal glandular region {{#pmid:23106811\|PMID23106811}}.		Similar to the first study, this one also focuses on the chromaffin cells and their relationship to the adrenal medulla. Chromaffin cells often represent the main endocrine component that is believed to differentiate from neural crest cells{{#pmid:28684471\|PMID28684471}}. The study focuses specifically on the idea that previous research has suggested that nerve - associated schwann cell precursor is a progenitor of chromaffin cells. What the findings suggested was that peripheral nerves provided migration routes for the progenitors. This is backed up by the results, a high concentration of chromaffin cells can be found being derived from the nerve, as nerve ablated mice in the experiment showed a large difference of 78% less cells compared to the control. Other than this, the study also brought to light the proliferative potential of the cells from nerves, with different other cell types being discovered as well (including cells such as parasympathetic{{#pmid:24925912\|PMID24925912}} and melanocytes {{#pmid:19837037 \|PMID19837037}}). The findings would provide useful information into further understanding the adrenal gland and its embryonic origins (as there is still much to learn regarding the formation of the adrenal medulla) but also pathological diseases such as neuroblastoma and pheochromatocytoma which are most common in the adrenal glandular region {{#pmid:23106811\|PMID23106811}}.

	Link to article: ~~{{#pmid~~:~~28684471\|PMID28684471}}~~		Link to article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6013038/

	===Glossary===		===Glossary===

Z5112688: /* Multipotent Peripheral Glial Cells Generate Neuroendocrine Cells of the Adrenal Medulla */

2018-10-16T08:10:01Z

Multipotent Peripheral Glial Cells Generate Neuroendocrine Cells of the Adrenal Medulla

← Older revision		Revision as of 19:10, 16 October 2018
Line 186:		Line 186:

	Similar to the first study, this one also focuses on the chromaffin cells and their relationship to the adrenal medulla. Chromaffin cells often represent the main endocrine component that is believed to differentiate from neural crest cells{{#pmid:28684471\|PMID28684471}}. The study focuses specifically on the idea that previous research has suggested that nerve - associated schwann cell precursor is a progenitor of chromaffin cells. What the findings suggested was that peripheral nerves provided migration routes for the progenitors. This is backed up by the results, a high concentration of chromaffin cells can be found being derived from the nerve, as nerve ablated mice in the experiment showed a large difference of 78% less cells compared to the control. Other than this, the study also brought to light the proliferative potential of the cells from nerves, with different other cell types being discovered as well (including cells such as parasympathetic{{#pmid:24925912\|PMID24925912}} and melanocytes {{#pmid:19837037 \|PMID19837037}}). The findings would provide useful information into further understanding the adrenal gland and its embryonic origins (as there is still much to learn regarding the formation of the adrenal medulla) but also pathological diseases such as neuroblastoma and pheochromatocytoma which are most common in the adrenal glandular region {{#pmid:23106811\|PMID23106811}}.		Similar to the first study, this one also focuses on the chromaffin cells and their relationship to the adrenal medulla. Chromaffin cells often represent the main endocrine component that is believed to differentiate from neural crest cells{{#pmid:28684471\|PMID28684471}}. The study focuses specifically on the idea that previous research has suggested that nerve - associated schwann cell precursor is a progenitor of chromaffin cells. What the findings suggested was that peripheral nerves provided migration routes for the progenitors. This is backed up by the results, a high concentration of chromaffin cells can be found being derived from the nerve, as nerve ablated mice in the experiment showed a large difference of 78% less cells compared to the control. Other than this, the study also brought to light the proliferative potential of the cells from nerves, with different other cell types being discovered as well (including cells such as parasympathetic{{#pmid:24925912\|PMID24925912}} and melanocytes {{#pmid:19837037 \|PMID19837037}}). The findings would provide useful information into further understanding the adrenal gland and its embryonic origins (as there is still much to learn regarding the formation of the adrenal medulla) but also pathological diseases such as neuroblastoma and pheochromatocytoma which are most common in the adrenal glandular region {{#pmid:23106811\|PMID23106811}}.

			Link to article: {{#pmid:28684471\|PMID28684471}}

	===Glossary===		===Glossary===

Z5112688: /* Generation of Adrenal Chromaffin-like Cells from Human Pluripotent Stem Cells */

2018-10-16T08:09:09Z

Generation of Adrenal Chromaffin-like Cells from Human Pluripotent Stem Cells

← Older revision		Revision as of 19:09, 16 October 2018
Line 181:		Line 181:
	==== Generation of Adrenal Chromaffin-like Cells from Human Pluripotent Stem Cells====		==== Generation of Adrenal Chromaffin-like Cells from Human Pluripotent Stem Cells====

	As explained above the adrenal medulla plays an important part in the autonomic system of an adult human. The chromaffin cells, in particular, are important neural crest derived cell that is closely related to the adrenal medulla. Previous findings have focused specifically on the mechanisms controlling the ~~NCC~~ migration and how these cells go on to form the different derivatives in their particular destinations in the embryo. For example, as previously explained studies have shown that chromaffin cells have been observed to move to the adrenal gland to form the medulla of the adrenal gland. This report goes through a recent study that involves the adrenal medullary cells, in particular chromaffin cells, and their potential to be used to model certain pathological diseases related to these cells. This is part of a study that also involves neural crest cells and their ability to differentiate into multiple different types of cells<ref>Lumb, R., & Schwarz, Q. (2015). Sympathoadrenal neural crest cells: The known, unknown and forgotten?. Development, Growth & Differentiation, 57(2), 146-157. doi: 10.1111/dgd.12189</ref>. Neural crest cells and SAPs from human embryonic cells and induced pluripotent stem cells were generated to be used in the experiment. By exposing the pluripotent stem cells to BMP4 in vitro, results showed that these cells would 'upregulate' the chromaffin cell - specific marker PMNT (an enzyme that synthesizes adrenaline). Furthermore when the cells from human embryos were implanted into avian embryos, there was a visible potential for the human cells to differentiate into cells that expressed the chromaffin cell markers{{#pmid:5768882\|PMID5768882}}.		As explained above the adrenal medulla plays an important part in the autonomic system of an adult human. The chromaffin cells, in particular, are important neural crest derived cell that is closely related to the adrenal medulla. Previous findings have focused specifically on the mechanisms controlling the neural crest cell migration and how these cells go on to form the different derivatives in their particular destinations in the embryo. For example, as previously explained studies have shown that chromaffin cells have been observed to move to the adrenal gland to form the medulla of the adrenal gland. This report goes through a recent study that involves the adrenal medullary cells, in particular chromaffin cells, and their potential to be used to model certain pathological diseases related to these cells. This is part of a study that also involves neural crest cells and their ability to differentiate into multiple different types of cells<ref>Lumb, R., & Schwarz, Q. (2015). Sympathoadrenal neural crest cells: The known, unknown and forgotten?. Development, Growth & Differentiation, 57(2), 146-157. doi: 10.1111/dgd.12189</ref>. Neural crest cells and SAPs from human embryonic cells and induced pluripotent stem cells were generated to be used in the experiment. By exposing the pluripotent stem cells to BMP4 in vitro, results showed that these cells would 'upregulate' the chromaffin cell - specific marker PMNT (an enzyme that synthesizes adrenaline). Furthermore when the cells from human embryos were implanted into avian embryos, there was a visible potential for the human cells to differentiate into cells that expressed the chromaffin cell markers{{#pmid:5768882\|PMID5768882}}.


	====Multipotent Peripheral Glial Cells Generate Neuroendocrine Cells of the Adrenal Medulla====		====Multipotent Peripheral Glial Cells Generate Neuroendocrine Cells of the Adrenal Medulla====

← Older revision		Revision as of 22:25, 16 October 2018
Line 31:		Line 31:
	[[File:Regions_of_NC_Cells.jpg\|left\|Neural crest regions\|thumb\|465px]]		[[File:Regions_of_NC_Cells.jpg\|left\|Neural crest regions\|thumb\|465px]]
	From the 1980s-1990s, the causative agent of organ transformation from one to another (homeotic patterning), as well as the Hox genes which regulate the axis of most symmetrical animal embryos were founded and studied. The neural crest, which previously was divided into the cranial and trunk regions, was now further divided into the vagal and sacral neural crest, the cardiac neural crest and the cephalic neural crest {{#pmid:19179766\|PMID19179766}}. The vagal & sacral neural crest gives rise to the parasympathetic ganglia found in the gut. Without these ganglia, peristalsis, is not possible <ref name=Gilbert2000>Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. The Neural Crest. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10065/</ref>. The cardiac neural crest contributes to the valves, septa and major blood vessels of the heart, as well as connective tissues and cartilage{{#pmid:19179766\|PMID19179766}}. This is important for the structure of the heart as well as its overall function, enabling it to move blood around the body efficiently as well as keep pulmonary and aortic circulation separated <ref name=Gilbert2000>Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. The Neural Crest. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10065/</ref>.		From the 1980s-1990s, the causative agent of organ transformation from one to another (homeotic patterning), as well as the Hox genes which regulate the axis of most symmetrical animal embryos were founded and studied. The neural crest, which previously was divided into the cranial and trunk regions, was now further divided into the vagal and sacral neural crest, the cardiac neural crest and the cephalic neural crest {{#pmid:19179766\|PMID19179766}}. The vagal & sacral neural crest gives rise to the parasympathetic ganglia found in the gut. Without these ganglia, peristalsis, is not possible <ref name=Gilbert2000>Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. The Neural Crest. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10065/</ref>. The cardiac neural crest contributes to the valves, septa and major blood vessels of the heart, as well as connective tissues and cartilage{{#pmid:19179766\|PMID19179766}}. This is important for the structure of the heart as well as its overall function, enabling it to move blood around the body efficiently as well as keep pulmonary and aortic circulation separated <ref name=Gilbert2000>Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. The Neural Crest. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10065/</ref>.

			In the mid 1980s, the first studies bringing about some information on the destination of ventrally migrating neural crest cells were conducted using the antibody HNK-1, as it is known to detect antigens on neuroectodermal cells & label the migratory cells. Where previously it was thought that trunk neural crest cells migrated whilst avoiding the somites, these studies showed that the trunk neural crest cells migrated through the rostral half of each somite. How this worked was eventually understood as a result of chemotactic factors that attract and repel the cells to follow this migration {{#pmid:26970616\|PMID26970616}}.


	Today, knowledge of the neural crest cells, their migration patterns, modes of differentiation, derivatives and apoptosis (cell death) are being studied extensively. This is being done on a comparative basis between different organisms, to add further evidence for evolution {{#pmid:19179766\|PMID19179766}}. The neural crest is definitely forging a "crest" between the fields of developmental and evolutionary biology, as it is a structure '''shared exclusively by all vertebrates'''. Invertebrates do not derive their specialised cells from the neural crest as they do not have one, rather, they derive these from the endomesoderm {{#pmid:22230617\|PMID22230617}}.		Today, knowledge of the neural crest cells, their migration patterns, modes of differentiation, derivatives and apoptosis (cell death) are being studied extensively. This is being done on a comparative basis between different organisms, to add further evidence for evolution {{#pmid:19179766\|PMID19179766}}. The neural crest is definitely forging a "crest" between the fields of developmental and evolutionary biology, as it is a structure '''shared exclusively by all vertebrates'''. Invertebrates do not derive their specialised cells from the neural crest as they do not have one, rather, they derive these from the endomesoderm {{#pmid:22230617\|PMID22230617}}.


	'''Future directions'''		'''Future directions'''

	Since its discovery by His, the neural crest field has made great progress, from studies performed on the structure, to analysis of the molecules and whether certain aspects of the neural crest are specific to a single species of organism, or to all vertebrates collectively. Future work on the cranial neural crest needs to be done as well as identifying and categorising the networks responsible for the proliferation and death of cells, as well as how the cells move and migrate, as well as the gene regulatory networks (GRNs) that regulate the synthesis of proteins. Advances in technology will undeniably lead us to more answers on the subject {{#pmid:~~22230617~~\|~~PMID22230617~~}}.		Since its discovery by His, the neural crest field has made great progress, from studies performed on the structure, to analysis of the molecules and whether certain aspects of the neural crest are specific to a single species of organism, or to all vertebrates collectively. Future work on the cranial neural crest needs to be done as well as identifying and categorising the networks responsible for the proliferation and death of cells, as well as how the cells move and migrate, as well as the gene regulatory networks (GRNs) that regulate the synthesis of proteins {{#pmid:22230617\|PMID22230617}}.
			. Advances in technology will undeniably lead us to more answers on the subject and studies that include imaging, mathematical and molecular modelling will greatly enhance our growing understanding of how neural crest cells move {{#pmid:26970616\|PMID26970616}}.

	===Developmental time course===		===Developmental time course===