Intra-septal infusions of excitatory amino acid receptor antagonists have differential effects in two animal models of anxiety.
Ablation or pharmacological inhibition of the septum produces anxiolytic-like effects in two animal models of anxiety: the elevated plus-maze and the shock-probe burying tests. Overall, these results suggest that the septum normally plays an excitatory role in the control of anxiety-related behaviors. The purpose of the present study was to examine this hypothesis in more detail, by testing the effects of intra-septal infusions of excitatory amino acid (EAA) receptor antagonists on rats' behavior in the shock-probe and plus-maze tests. We found that intra-septal infusions of the non-NMDA (N-methyl-D-aspartic acid) receptor antagonist CNQX (5 microg) suppressed open-arm avoidance in the plus-maze test, and reduced burying behavior in the shock-probe test, without affecting rats' normal avoidance of the shock-probe. In contrast, intra-septal infusions of the NMDA receptor antagonist AP-5 (5 microg) inhibited both shock-probe avoidance and burying behavior, without affecting rats' open-arm avoidance. These dissociations suggest that different EAA receptor types within the septum exert complex but distinct control of different anxiety-related behaviors.
Menard
J
J
Douglas Hospital Research Center, Montreal, PQ, Canada. menjan@douglas.mcgill.ca
Treit
D
D
D015763:2-Amino-5-phosphonovalerate / Q000008:administration & dosage / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001007:Anxiety / Q000188:drug therapy* / Q000523:psychology; D004597:Electroshock; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D007267:Injections; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects; D020665:Septum of Brain / Q000033:anatomy & histology / Q000502:physiology*
D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate