Involvement of L-type Ca2+ channels in the induction of long-term potentiation in the basolateral amygdala-dentate gyrus pathway of anesthetized rats.
We have recently found that synaptic pathway from the basolateral amygdala (BLA) to the dentate gyrus (DG) displays N-methyl-D-aspartate (NMDA) receptor-independent form of long-term potentiation (LTP), which should be a valuable model for elucidating neural mechanisms linking emotion and memory. To explore its cellular mechanisms, we investigated the effects of L-type Ca(2+) channel blockers on LTP in this pathway of anesthetized rats. Intraperitoneal administration of verapamil (3-30 mg/kg) or diltiazem (6-20 mg/kg) significantly impaired the induction of LTP following high-frequency stimulation. When verapamil was administered after high-frequency stimulation, it did not affect the pre-established LTP. These results suggest that activation of L-type Ca(2+) channels is necessary for the induction of LTP in the BLA-DG pathway.
Niikura
Yoshiaki
Y
Department of Pharmacology, School of Pharmacy, Hoshi University, Tokyo 142-8501, Japan.
Abe
Kazuho
K
Misawa
Miwa
M
D000679:Amygdala / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000502:physiology*; D018891:Dentate Gyrus / Q000187:drug effects / Q000502:physiology*; D004110:Diltiazem / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation / Q000379:methods; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D008297:Male; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D014700:Verapamil / Q000494:pharmacology
D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D014700:Verapamil; D004110:Diltiazem