Development of the alpha 7 nicotinic cholinergic receptor in rat hippocampal formation

• Published in: Brain research. Developmental brain research 2002-12, Vol.139 (2), p.175-187
• Main Authors: Adams, CE, Broide, R S, Chen, Y, Winzer-Serhan, U H, Henderson, T A, Leslie, F M, Freedman, R
• Format: Article
• Language: English
• ISSN: 0165-3806
• DOI: 10.1016/S0165-3806(02)00547-3

The alpha 7 nicotinic receptor has been implicated in the regulation of a variety of developmental processes. The goal of the present study was to assess whether the alpha 7 receptor might participate in the regulation of hippocampal ontogeny by describing the spatiotemporal development of alpha 7 mRNA and alpha -bungarotoxin binding in rat hippocampal formation. Message for the alpha 7 receptor was initially observed in the hippocampal neuroepithelium at embryonic day 13 and in the anlage of the hippocampal formation on embryonic day 14. Binding of alpha -bungarotoxin was initially seen on embryonic day 15 in the dorsal portion of the anlage of stratum oriens and stratum radiatum-lacunosum moleculare, but was never observed in the neuroepithelium. Dramatic elevations in both alpha 7 mRNA and alpha -bungarotoxin binding were observed in most regions of the hippocampal formation neonatally. The levels of both alpha 7 message and protein gradually decreased during the first three postnatal weeks to adult levels in most regions. The lack of alpha -bungarotoxin binding in the neuroepithelium suggests that the alpha 7 receptor does not influence neurogenesis. The early appearance and complex, prolonged pattern of development of the alpha 7 receptor suggest that it may influence processes as diverse as cell migration, dendritic elaboration and apoptosis during hippocampal maturation.