TY - JOUR T1 - T-type calcium channels: heterogeneous expression in rat sensory neurons and selective modulation by phorbol esters JF - The Journal of Neuroscience JO - J. Neurosci. SP - 947 LP - 951 DO - 10.1523/JNEUROSCI.10-03-00947.1990 VL - 10 IS - 3 AU - JE Schroeder AU - PS Fischbach AU - EW McCleskey Y1 - 1990/03/01 UR - http://www.jneurosci.org/content/10/3/947.abstract N2 - We report selective inhibition of low-threshold, T-type calcium channels by a phorbol ester in rat sensory neurons. Cells were exposed, either acutely or with 15–60 min preincubations, to low concentrations of phorbol 12-myristate 13-acetate, (PMA), an activator of protein kinase C; if the temperature was 29 degrees C or higher, T-type Ca current was diminished without effect on high-threshold Ca current. In untreated cells, the amplitude of T-type Ca current varies widely among neighboring sensory neurons. T channels are absent in about 25% of cells, provide a small current near threshold for the majority of cells, and are a dominant pathway for calcium entry in a small subset of neurons. The results are of interest because, by selectively inhibiting a calcium channel expressed differently among subpopulations of sensory neurons, activation of protein kinase C might selectively suppress particular sensations. ER -