SLOW-WAVE SLEEP IS ACCOMPANIED BY RELEASE OF CERTAIN AMINO-ACIDS IN THE THALAMUS OF CATS

To determine whether EEG synchronization in sleep has a metabolic equi valent, we investigated state-dependent changes in extracellular conce ntrations of amino acids. In vivo microdialysis studies were performed in the ventroposterolateral (VPL) nuclei of the thalamus of cats duri ng natural slow wave sleep (SWS), waking (W) and carbachol-induced par adoxical sleep (PS) like episodes. About two-fold increases in asparta te, glutamate, asparagine, glycine, alanine and gamma-aminobutyric aci d (GABA) were observed in SWS compared with control samples collected in W, but serine increased to 487 +/- 211%. In the PS-like state, glut amine increased and GABA decreased. These results suggest changes in i ntracellular processes reflected by amino acid release in the thalamus , specific to slow wave generation in EEG during natural sleep.