R. Gutierrez et al., ZINC INHIBITS CA3 AND DENTATE ORTHODROMIC RESPONSES BUT ENHANCES DENTATE ANTIDROMIC RESPONSES IN RAT HIPPOCAMPAL SLICES, Neuroscience research communications, 17(2), 1995, pp. 89-95
The divalent cation zinc (Zn2+) exerts multiple effects on transmitter
receptors and voltage gated ion channels and may act as an endogenous
modulator of neuronal function. Most of the specific blocking effects
on transmitter-activated ion channels display apparent K-D values in
the lower micromolar range. We therefore tested the effect of low conc
entrations of Zn2+ (1-25 mu M) on synaptic transmission in adult rat h
ippocampal slices using field potential recordings. Zn2+ reduced popul
ation spikes in CA3 and in area dentata upon orthodromic stimulation.
Interestingly, antidromically evoked population spikes in area dentata
were slightly but consistently enhanced by Zn2+. Pahed pulse inhibiti
on was unchanged in CA3 and area dentata. The results indicate that Zn
2+ at low concentrations reduces synaptically evoked responses in CA3
and area dentata without selectively affecting paired pulse inhibition
.