N-(5-Hydroxynicotinoil)-L-Glutamic Acid Calcium Salt Modifies Responses of Rat Hippocampal CA1 Pyramidal Neurons during Orthodromic Stimulation

Abstract

The study examined the effect of calcium salt of N-(5-hydroxynicotinoil)-L-glutamic acid (Ampasse preparation) on neuronal activity in hippocampal CA1 area evoked by stimulation of Schaffer collaterals at a rate of 1 Hz (30 impulses during 30 sec) in the surviving hippocampal slices of Wistar rats. The records of 1st and 30th orthodromic population spikes showed that Ampasse in concentrations of 500 μM, 1, 2, and 10 mM facilitated the synaptic transmission in Schaffer collaterals - hippocampal CA1 pyramidal neurons axis; the maximum effect was observed at 2 mM Ampasse. When used in a concentration of 10 mM, Ampasse provoked epileptiform activity, which could be prevented by MK-801, a specific noncompetitive antagonist of the NMDA-receptor complex.