WHOLE-CELL RECORDINGS OF SPONTANEOUS SYNAPTIC CURRENTS IN MEDIAL PREOPTIC NEURONS FROM RAT HYPOTHALAMIC SLICES - MEDIATION BY AMINO-ACID NEUROTRANSMITTERS

Whole-cell recordings in hypothalamic slices from immature rats were u sed to test the hypothesis that inhibitory and excitatory amino acid n eurotransmitters mediate fast synaptic currents in the medial preoptic area (MPOA). Bicuculline methiodide reversibly blocked spontaneous in hibitory postsynaptic currents (IPSCs), and 6-cyano-2,3-dihydroxy-7-ni troquinoxaline (CNQX) blocked spontaneous excitatory postsynaptic curr ents (EPSCs). These competitive antagonists act at gamma-aminobutyric acid (GABA), and non-N-methyl-D-aspartate (NMDA) glutamate receptors, respectively, thus supporting the hypothesis that these amino acid rec eptors activate most if not all fast synaptic currents in the MPOA.