The role of Ca2+ channels in the repetitive firing of striatal projection neurons.
Blockade of L-type Ca2+ channels results in a decrease in firing frequency of neostriatal neurons. In contrast, N- and P/Q-types of Ca2+ channel cooperate to tune firing pattern, since both of these channel types have to be blocked to enhance firing frequency. Parameters of the intensity-frequency plot were differentially modified by Ca2+ channel antagonists: while L-type Ca2+ channel block reduced the dynamic range by about 80%, block of N- and P/Q-types of Ca2+ channel generated a steeper intensity-frequency plot. These effects are explained in terms of the sustained depolarization and the afterhyperpolarizing potential known to be dependent upon L- and N-, P/Q-types of Ca2+ channels, respectively.
Pérez-Garci
Enrique
E
Departamento de Biofísica, Instituto de Fisiología Celular, UNAM, DF México.
Bargas
José
J
Galarraga
Elvira
E
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000502:physiology*; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
D002121:Calcium Channel Blockers; D015220:Calcium Channels