Postsynaptic control of hippocampal long-term potentiation.

摘要: Long-term potentiation (LTP) in the hippocampus has property of cooperativity, i.e. greater is produced if a larger number afferent fibres tetanized. The possible involvement postsynaptic mechanisms this process was investigated CA1 area hippocampal slice preparation. Following blockade inhibition by GABA antagonists, e.g. picrotoxin, induction LTP greatly facilitated. In picrotoxin-treated slices, induced pathway stimulated single volleys, these occurred conjunction with brief tetanic activation other afferents. This interaction operated over short period time (less than 50 ms) and also present inputs were separated space (cooperativity between to basal apical dendrites). could be pairing volley synaptic intracellularly injected depolarizing current pulses, timing requirements being similar those observed extracellular "conjunction studies". Previous studies have suggested that glutamate receptor channels N-methyl-D-aspartate (NMDA) type are somehow involved induction. Evidence presented here shows leading evokes potential which sensitive NMDA blocker 2-amino-5-phosphonovalerate (APV), indicating passage through channels. results suggest depends on simultaneous presynaptic transmitter release depolarization manner analogous model proposed HEBB (1949) for associative learning. Furthermore, it required pre- handled channel complex, known voltage sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)