Excitation of rat hippocampal neurones by the stereoisomers of cis- and trans-1-amino-1,3-cyclopentane dicarboxylate.
Intracellular recordings were obtained from rat hippocampal neurons during the microiontophoretic ejection of the stereoisomers of cis- and trans-1-amino-1,3-cyclopentane dicarboxylate into the dendritic region (stratum radiatum) of the impaled cells. L-(+)-cis-1-Amino-1,3-cyclopentane dicarboxylate, D(+)-trans-1-amino-1,3-cyclopentane dicarboxylate, and L-(-)-trans-1-amino-1,3-cyclopentane dicarboxylate all evoked patterns of excitation resembling that elicited by kainate. All of these responses were unaffected by D-(-)-2-amino-5-phosphonovalerate but were antagonized at comparable currents by kynurenate. The excitation produced by D-(-)-cis-1-amino-1,3-cyclopentane dicarboxylate was similar to that evoked by N-methyl-D-aspartate. At low ejection currents a slow depolarization triggered rhythmic burst firing, each burst consisting of a depolarizing shift in membrane potential upon which were superimposed four to five action potentials. These responses were antagonized both by D-(-)-2-amino-5-phosphonovalerate and by kynurenate. The results are discussed with respect to the conformational requirements considered to be necessary for interaction at the kainate and N-methyl-D-aspartate receptors on CA1 pyramidal neurones. It is important to note that the isopropylene side chain of kainate is absent from the 1-amino-1-3-cyclopentane dicarboxylate molecule.
Curry
K
K
Department of Physiology, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
Magnuson
D S
DS
McLennan
H
H
Peet
M J
MJ
D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D003292:Convulsants / Q000008:administration & dosage / Q000494:pharmacology; D003515:Cycloleucine / Q000494:pharmacology*; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D066298:In Vitro Techniques; D007478:Iontophoresis; D007736:Kynurenic Acid / Q000494:pharmacology; D008297:Male; D009474:Neurons / Q000187:drug effects*; D010069:Oxadiazoles / Q000008:administration & dosage / Q000494:pharmacology; D011712:Pyramidal Tracts / Q000187:drug effects; D016318:Quisqualic Acid; D051381:Rats; D013237:Stereoisomerism
D000596:Amino Acids; D003292:Convulsants; D010069:Oxadiazoles; D003515:Cycloleucine; D016318:Quisqualic Acid; D007736:Kynurenic Acid