Long-lasting potentiation produced by a phorbol ester in the hippocampus of the anaesthetized rat is not associated with a persistent enhanced release of excitatory amino acids.
The relationship between the long-lasting enhancement of synaptic transmission produced by a phorbol ester and the release of endogenous excitatory amino acids has been investigated in the CA1 hippocampal region of the anaesthetized rat. Using the push-pull technique, the concentration of glutamate and aspartate was assayed in the perfusate by high-pressure liquid chromatography. Application of phorbol 12-13 diacetate produced a long lasting enhancement of the field excitatory postsynaptic potential (EPSP) (over 2 h). This was associated with a brief (10 min) significant increase in the release of glutamate and aspartate. However, subsequently the levels of the amino acids in the perfusate were not different from the pre-drug (control) levels although the field EPSP was still enhanced. It is concluded that the long-lasting enhancement produced by phorbol ester is not due to a persistent increase in the release of excitatory amino acids.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D010703:Phorbol Esters / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D005971:Glutamates; D010703:Phorbol Esters; C008874:phorbol-12,13-diacetate; D001224:Aspartic Acid; D018698:Glutamic Acid