Observations of synaptic efficacy and paired-pulse facilitation in area CA1 of hippocampal slices from coriaria lactone-kindled rats.
The changes of population spike(PS)/population excitatory postsynaptic potential (EPSP) slope relationship and paired-pulse facilitation (PPF) were primarily investigated with extracellular recording in stratum pyramidale to stimulation of Schaffer collaterals in CA1 region of hippocampal slices from coriaria lactone (CL)-kindled and control rats. The results were as follows: (1) neither spontaneous nor evoked epileptiform bursts were found in all hippocampal slices from CL-kindled and control rats; (2) the synaptic efficacy, expressed by the ratio of PS/EPSP slope, at low stimulation intensity ranging from 10-30% of its maximum was significantly increased on CL-kindled rats (P less than 0.05); and (3) although PPF was found in all slices, the PPF strength only at stimulation intensity of 10 and 20% of maximum was augmented remarkably in CL-kindled rats (P less than 0.002 and 0.024, respectively). According to the results from our previous work, we suggested that the increment of PS/EPSP slope ratio and PPF strength at low stimulation intensity may result from the potentiation of excitatory synaptic activity or/and the change of intrinsic excitability of pyramidal neurons.
Guo
L
L
Department of Physiology, West China University of Medical Sciences, Chengdu.
Chai
H
H
Liu
X
X
Xie
Y
Y
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004365:Drugs, Chinese Herbal; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D066298:In Vitro Techniques; D007696:Kindling, Neurologic / Q000187:drug effects*; D007783:Lactones; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000187:drug effects*
D004365:Drugs, Chinese Herbal; D007783:Lactones; C049836:coriaria lactone