| Abstract: | Field potentials (FP) induced in the radial layer of area CAl by stimulating Schaffer's collaterals (C2) were recorded in murine hippocampal slices and associative long-term potentiation (ALP) produced by combined tetanization of C2 and another group of fibers (C1) was investigated. The effects of simultaneous (C1 and C2) and successive activation (with C1 preceding C2 by 200 msec) of the two inputs were compared. Tetanization preceded by activation of C1 ("conditioning" input) was more effective in experiments with short (30 msec, 100 Hz) trains of stimuli. Tetanization with simultaneous activation of the two inputs as well as tetanization of C1 input by prolonged (150 msec) spike trains with inhibition were blocked by 5·10–6 M picrotoxin. It is suggested that ALP induced by short trains of stimuli succeeding at 200 msec intervals serves as a more suitable model of memory than that induced by prolonged trains (of 1 sec).Brain Research Institute, National Mental Health Research Center, Academy of Sciences of the USSR, Moscow. Institute of Chemical Physics, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 22, No. 2, pp. 215–223, March–April, 1990. |
