title: Role of calcineurin in activity-dependent pattern formation in the dorsal lateral geniculate nucleus of the ferret.
abstract: In the retinogeniculate pathway of the ferret, in addition to the separation of the inputs from the two eyes to form eye-specific layers, there is also an anatomical segregation of the terminal arbors of on-center retinal ganglion cells from the terminal arbors of off-center retinal ganglion cell axons to form on/off sublaminae. Sublamination normally occurs during postnatal weeks 3-4 and requires the activity of retinal afferents, N-methyl-D-aspartate receptors, nitric oxide synthase, and a target of nitric oxide, cyclic guanosine monophosphate. Calcineurin is a calcium/calmodulin dependent serine, threonine protein phosphatase suggested to mediate NMDA-receptor dependent synaptic plasticity in the hippocampus. We have examined whether calcineurin plays a role during on/off sublamination in the dorsal lateral geniculate nucleus (dLGN) of the ferret. Immunohistochemistry showed that calcineurin expression is transiently up-regulated in dLGN cells and neuropil during the period of on/off sublamination. A functional role for calcineurin during sublamination was investigated by blocking the enzyme locally via intracranial infusion of FK506. Treatment with FK506 during postnatal weeks 3-4 disrupted the appearance of sublaminae. These results suggest that calcineurin may play a role during this process of activity-dependent pattern formation in the visual pathway.
authors.affiliation: Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Leamey
authors.forename: Chrystal L
authors.initials: CL
authors.lastname: Ho-Pao
authors.forename: Mriganka
authors.initials: M
authors.lastname: Sur
mesh_terms: D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D000918:Antibody Specificity; D019703:Calcineurin / Q000096:biosynthesis / Q000502:physiology*; D005289:Ferrets / Q000502:physiology*; D005829:Geniculate Bodies / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D019581:Neuropil / Q000378:metabolism; D012160:Retina / Q000502:physiology; D016559:Tacrolimus / Q000494:pharmacology; D015854:Up-Regulation
chemical_list: D007166:Immunosuppressive Agents; D019703:Calcineurin; D016559:Tacrolimus