Long-term potentiation in commissural and Schaffer projections to hippocampal CA1 cells: an in vivo study in the rat.

Rats were given unilateral injections of kainic acid into the lateral ventricle to produce a unilateral lesion of CA3 pyramidal cells in the hippocampus. This procedure allowed the commissural and associational Schaffer projections of the surviving contralateral CA3 field to be studied separately for their ability to sustain long-term potentiation (l.t.p.) of synaptic efficacy. Both Schaffer and commissural projections showed l.t.p. of the population excitatory post-synaptic potential (e.p.s.p.) and the population spike. No significant difference was seen in the degree or duration of l.t.p. sustained by the two projections.