Voltage-gated Ca2+ channel blockers, omega-AgaIVA and Ni2+, suppress the induction of theta-burst induced long-term potentiation in guinea-pig hippocampal CA1 neurons.
It is widely believed that a rise in post-synaptic calcium concentration ([Ca2+]i) is a necessary step in the induction of long-term potentiation (LTP) (Bliss and Collingridge, Nature, 361 (1993) 31-39). In this experiment, we examine the involvement of voltage-gated Ca2+ channels (VGCC) in the induction of AP5-sensitive LTP induced by theta-burst stimulation in guinea-pig hippocampal CA1 neurons. The VGCC blockers, Ni2+ (25 microM, T-channel blocker) or omega-AgaIVA (60 nM, P-channel blocker), which have no effect on synaptic transmission, suppress 60% or 78% of the theta-burst induced LTP, respectively. This implies that Ca2+ entry through VGCC is an important step in this form of LTP.
Ito
K
K
Department of Physiology, Yamagata University School of Medicine, Japan.
Miura
M
M
Furuse
H
H
Zhixiong
C
C
Kato
H
H
Yasutomi
D
D
Inoue
T
T
Mikoshiba
K
K
Kimura
T
T
Sakakibara
S
S
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D006168:Guinea Pigs; D006624:Hippocampus / Q000502:physiology*; D017774:Long-Term Potentiation / Q000187:drug effects*; D009532:Nickel / Q000494:pharmacology*; D009543:Nifedipine / Q000494:pharmacology; D018408:Patch-Clamp Techniques
D002121:Calcium Channel Blockers; D015763:2-Amino-5-phosphonovalerate; D009532:Nickel; D009543:Nifedipine; D002118:Calcium