Zinc reduces low-threshold Ca2+ currents of rat thalamic relay neurons.
Whole-cell voltage-clamping of thalamic relay neurons was used to examine the possibility of a Zn(2+)-mediated reduction of the low-threshold transient Ca(2+) current (I(T)) of a central element in thalamocortical oscillations. We found that Zn(2+) reversibly decreased I(T) in a concentration-dependent manner (IC(50)=55 microM), mainly by reducing the number of I(T) channels available for activation. Zn(2+) did not affect the reaction kinetics, but did affect the voltage-dependence of I(T) channel gating. However, the apparent alterations in gating properties were not enough to account for the huge I(T) reduction.
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000502:physiology*; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013788:Thalamus / Q000187:drug effects* / Q000502:physiology; D015032:Zinc / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D015032:Zinc