Age- and experience-dependent expression of dynamin I and synaptotagmin I in cat visual system.
Dynamin I (Dyn I) and Synaptotagmin I (Syt I) are essential for endocytosis-exocytosis processes, thus for neurotransmission. Despite their related function at presynaptic terminals, Dyn I and Syt I displayed opposite expression patterns during visual cortex maturation in the cat. Dyn I was more abundantly expressed in adults, while Syt I exhibited higher levels in kittens of postnatal day 30 (P30). In area 17 this developmental difference was most obvious in layers II/III. Layer VI displayed a strong hybridization signal for both molecules, independent of age. In addition, Syt I levels were higher in posterior compared to anterior area 17 in adult subjects. Moreover, in higher-order visual areas Syt I was unevenly distributed over the cortical layers, thereby setting clear areal boundaries in mature cortex. In contrast, Dyn I was rather homogeneously distributed over extrastriate areas at both ages. Both molecules thus demonstrated a widespread but different distribution and an opposite temporal expression pattern during visual system development. Notably, monocular deprivation during the critical period of ocular dominance plasticity significantly decreased Syt I expression levels in area 17 ipsilateral to the deprived eye, while no effect was observed on Dyn I expression. We therefore conclude that visual experience induces changes in Syt I expression that may reflect changes in constitutive exocytosis involved in postnatal structural refinements of the visual cortex. On the other hand, the spatial and temporal expression patterns of Dyn I correlate with the establishment and maintenance of the mature neuronal structure rather than neurite remodeling.
Cnops
Lieselotte
L
Laboratory of Neuroplasticity and Neuroproteomics, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium.
Hu
Tjing-Tjing
TT
Vanden Broeck
Jozef
J
Burnat
Kalina
K
Van Den Bergh
Gert
G
Arckens
Lutgarde
L
D000367:Age Factors; D000818:Animals; D002415:Cats; D003423:Critical Period, Psychological; D023882:Dominance, Ocular / Q000502:physiology*; D034284:Dynamin I / Q000378:metabolism*; D009473:Neuronal Plasticity; D050863:Synaptotagmin I / Q000378:metabolism*; D015349:Vision, Monocular / Q000502:physiology; D014793:Visual Cortex / Q000254:growth & development / Q000378:metabolism; D014795:Visual Pathways / Q000254:growth & development / Q000378:metabolism*; D014796:Visual Perception / Q000502:physiology*
D050863:Synaptotagmin I; D034284:Dynamin I