| dc.contributor.author | Abdel-Majid, Raja' M. | en_US |
| dc.date.accessioned | 2014-10-21T12:35:17Z | |
| dc.date.available | 1999 | |
| dc.date.issued | 1999 | en_US |
| dc.identifier.other | AAINQ57357 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55706 | |
| dc.description | Somatotopic maps are a fundamental feature in the organization of somatic sensory systems in the mammalian central nervous system. A striking example of these maps is present in the rodent cortex. Periphery-related patterns are evident in histological sections of layer IV of the primary somatosensory (SI) cortex in what is known as "barrels". The objective of the studies presented in this dissertation was to identify molecular and cellular mechanisms that underlie pattern formation in the cerebral cortex using the barrel field. | en_US |
| dc.description | Barrelless (brl) mutant mice fail to develop neuronal arrangements of barrels in their SI cortex. High resolution linkage and physical maps and candidate gene analysis strategies were followed to isolate and identify the brl gene. We identified adenylyl cyclase type I gene (Adcyl) as the gene disrupted in brl mutants. These results provide the first evidence for the involvement of cyclic nucleotide signaling pathways in pattern formation of the SI cortex and additionally argues that neuronal activity plays a role in the formation of periphery-related patterns in the SI cortex. | en_US |
| dc.description | In order to investigate whether cAMP-dependent protein kinase (PKA) acts in the same developmental pathway as Adcyl, we examined the SI cortex of five PKA null mutant mice (Prkar1b, Prkar2a, Prkar2b, Pkaca, and Pkacb). Our results reveal the presence of normal barrels in the SI cortex of all knockout mice, except for one that displayed poorly-formed barrels. These results suggest that Adcyl acts in the thalamocortical afferents, whereas PKA acts on layer IV cortical neurons. | en_US |
| dc.description | Since neurotrophins have recently been implicated in synaptic plasticity during development, we investigated their role in the development of barrels in the SI cortex. Our results indicate that intracortical injections of exogenous brain-derived neurotrophic factor and neurotrophin-3 can produce a barrelless phenocopy, and that absence of neurotrophin-4/5 in knockout mice results in poorly-formed barrels. Collectively, these results indicate a new role for neurotrophins in pattern formation of the cerebral cortex. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1999. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Anatomy. | en_US |
| dc.subject | Biology, Neuroscience. | en_US |
| dc.title | Molecular mechanisms underlying pattern formation in the mouse somatosensory cortex. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
