Differential conduction velocities in perforant path fibres in guinea pig

Conduction velocities (c.vs) of different hippocampal fibre groups have been measured in slices in vitro. In the mossy fibres, Schaffer collaterals and Str. oriens fibres the c.v. varied from 0.36-0.38 m/s; in the alveus c.v. was 1.20 m/s. In the perforant path (p.p.) two groups of c.vs were found: in the medial p.p. the mean (+/- s.e) c.v. was 0.32 +/- 0.02 m/s, whereas in the lateral p.p. it was 1.36 +/- 0.14 m/s.