The role of Ca2+ channels in the repetitive firing of striatal projection neurons

Abstract

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.