Age- and experience-dependent expression of Dynamin I and Synaptotagmin I in cat visual system

• Published in: Journal of comparative neurology (1911) Vol. 504; no. 3; pp. 254 - 264
• Main Authors: Cnops, Lieselotte, Hu, Tjing-Tjing, Vanden Broeck, Jozef, Burnat, Kalina, van den Bergh, Gert, Arckens, Lutgarde
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 20-09-2007
• Subjects: Age Factors; Animals; Cats; Critical Period (Psychology); development; distribution; Dominance, Ocular - physiology; Dyn I; Dynamin I - metabolism; monocular deprivation; Neuronal Plasticity; plasticity; Synaptotagmin I - metabolism; Syt I; Vision, Monocular - physiology; Visual Cortex - growth & development; Visual Cortex - metabolism; Visual Pathways - growth & development; Visual Pathways - metabolism; Visual Perception - physiology
• ISSN: 0021-9967; 1096-9861
• DOI: 10.1002/cne.21415

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. J. Comp. Neurol. 504:254–264, 2007. © 2007 Wiley‐Liss, Inc.