Medical amygdala-induced spike potentiation in the rat dentate gyrus is dependent on N-methyl-D-aspartate receptors and subcortical afferents.
We have previously found that high-frequency stimulation of the medial amygdala (MeA) produces a long-lasting potentiation of the population spike at medial perforant path-granule cell synapses in the dentate gyrus of anesthetized rats. The present study was performed to determine whether this novel form of potentiation requires activation of N-methyl-D-aspartate (NMDA) receptors and subcortical afferents. The MeA-induced spike potentiation was completely blocked by the NMDA receptor antagonist 3-((R,S)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (3.5 mg/kg, i.p). When the fimbria-fornix, a major pathway of subcortical afferents, was lesioned, the early phase of MeA-induced spike potentiation remained intact, but the late phase of potentiation was abolished. These results suggest that the NMDA receptor is essentially required for the induction of MeA-induced spike potentiation, while subcortical afferents contribute to the establishment of potentiation.
Abe
K
K
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, The University of Tokyo, Japan.
Noguchi
K
K
Saito
H
H
D000344:Afferent Pathways / Q000502:physiology*; D000679:Amygdala / Q000502:physiology*; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D018891:Dentate Gyrus / Q000502:physiology; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D007839:Functional Laterality; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D010879:Piperazines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology
D018691:Excitatory Amino Acid Antagonists; D010879:Piperazines; D016194:Receptors, N-Methyl-D-Aspartate; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid