title: Excitatory amino acids mediate responses elicited in vitro by stimulation of cortical afferents to reticularis thalami neurons of the rat.
abstract: The effects of the excitatory amino acids on the nucleus reticularis thalami were examined by intracellular recordings from rat thalamic slices. Non-N-methyl-D-aspartate receptor agonists and glutamate induced a membrane depolarization and a reduction in input resistance, while N-methyl-D-aspartate and aspartate induced a prolonged discharge, which in some neurons took the form of a burst firing associated with an apparent increase in membrane input resistance. Both the N-methyl-D-aspartate and the aspartate effects were blocked by D-2-amino-5-phosphonovalerate, while the effects of glutamate, kainate and quisqualate were not. The excitatory postsynaptic potential evoked by corticothalamic fiber stimulation shows two components: an early, short-lasting, 2-amino-5-phosphonovalerate-insensitive portion, and a late, 2-amino-5-phosphonovalerate-sensitive decay phase. It is suggested that glutamate acts in nucleus reticularis thalami cells preferentially on the non-N-methyl-D-aspartate receptors, while aspartate shows an N-methyl-D-aspartate-like effect. The two excitatory amino acids glutamate and aspartate play a determinant role in the modulation of thalamic activity driven by corticothalamic projection.
authors.affiliation: Department of Neurophysiology, Istituto Neurologico Carlo Besta, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: de Curtis
authors.forename: R
authors.initials: R
authors.lastname: Spreafico
authors.forename: G
authors.initials: G
authors.lastname: Avanzini
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000502:physiology*; D066298:In Vitro Techniques; D016202:N-Methylaspartate; D051381:Rats; D011919:Rats, Inbred Strains; D013788:Thalamus / Q000187:drug effects / Q000502:physiology*
chemical_list: D000596:Amino Acids; D001224:Aspartic Acid; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate