LITHIUM ENHANCES SYNAPTIC TRANSMISSION IN NEONATAL RAT HIPPOCAMPUS

The effects of lithium on excitatory synaptic transmission were studie d in the CA1 region of hippocampal slices taken from 14- to 30-day-old rats using extracellular recording techniques. Lithium (2-18 mM) reve rsibly increased the field excitatory postsynaptic potentials in a con centration-dependent manner. Application of lithium for 6-15 min had n o effect on the synaptic input-output function, while application of l ithium for 20-35 min shifted this curve to the left. Lithium reversibl y increased the amplitude of the presynaptic fibre volley in a concent ration- and calcium-dependent manner. Lithium decreased paired-pulse f acilitation measured at 50-ms interstimulus intervals. The results ind icate that lithium enhances excitatory synaptic transmission in CAI py ramidal cells by at least two different actions. (C) 1997 IBRO. Publis hed by Elsevier Science Ltd.