[Acetylcholine decreases low threshold T-type calcium conductance of relay cells in the cat's lateral geniculate nucleus].

The effect of acetylcholine (ACh) on the low threshold T-type Ca2+ conductance of relay cells in the cat lateral geniculate nucleus (LGN) was studied using in vitro thalamic slices. Results from both current-clamp and voltage-clamp experiments showed that the low threshold Ca2+ conductance was inhibited by ACh in most (82%) of the LGN neurons tested, even when the membrane potential was clamped to the control level. This inhibitory effect was independent of the changes in membrane potential by ACh. Therefore, ACh might exert a direct action on low threshold Ca2+ channels.