Comparison of direct influences of the perforant path on hippocampal CA1 and CA3 neurons in vitro

The efficiency of synapses of the perforant path located on terminals of apical dendrites of CA₁ and CA₃ neurons was investigated in sections of the guinea pig hippocampus in vitro. Neurons of both areas were shown to respond to stimulation of the perforant path by action potential generation. Responses of most CA₁ neurons appeared to repetitive stimulation with a frequency of up to 30–80/sec. Neurons in area CA₃ respond only to low-frequency stimulation (under 5/sec). Posttetanic potentiation of responses to stimulation of the perforant path was found in both areas of the hippocampus.Institute of Biophysics, Academy of Sciences of the USSR, Pushchino-on-Oka. Translated from Neirofiziologiya, Vol. 11, No. 4, pp. 303–310, July–August, 1979.