title: The long-term facilitation of neuronal activity produced by repeated pairing of an orthodromic stimulus and antidromic stimuli in the sliced hippocampal formation.
abstract: Long-term facilitation in extracellularly recorded population spikes was demonstrated by repeated paired stimulation (RPS) in CA1 neurons of the guinea pig hippocampal slices. Paired stimulation, consisting of a single orthodromic "test" stimulus and a train (5 pulses at 200 Hz) of antidromic stimuli with an interstimulus interval (ISI) of 20, 500 msec or 1 sec was repeated every 5 sec over a 250 sec period. The amplitude of the population spike in response to the test stimulus increased gradually after RPS and reached a plateau level 30-50 min after RPS. The plateau value was dependent on ISI; the shorter the ISI the greater the increase of responses. In contrast, no facilitation was observed when either the test stimulus or the antidromic stimuli were applied separately, without pairing.
mesh_terms: D000200:Action Potentials; D000818:Animals; D004558:Electric Stimulation; D006168:Guinea Pigs; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D009474:Neurons / Q000502:physiology*; D013569:Synapses / Q000502:physiology