期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1991
卷号:88
期号:11
页码:4736-4740
DOI:10.1073/pnas.88.11.4736
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:A mutation at the tottering locus (tg, recessive, on chromosome 8) stimulates noradrenergic locus coeruleus axon terminal outgrowth and predisposes the brain to generalized spike-wave epilepsy in the young mouse. In an isolated synaptic circuit studied in vitro, the hyperinnervated mutant hippocampal pyramidal neurons respond normally when individually activated; however, latent neuronal signaling defects emerge during synchronous network bursting, revealing two conditional excitability phenotypes: a voltage-dependent prolongation of a complex synaptic response, the paroxysmal depolarizing shift, and a beta-adrenoreceptor-linked attenuation of the afterhyperpolarization. In this target brain region, the tg locus transforms neuronal excitability without altering measured intrinsic membrane properties, indicating that gene control of inherited epileptic traits may be mediated in part by activity-dependent modulation of network behavior favoring synchronous neuronal firing.