Zn2+ enhances the intrinsic bursting activity of a rat thalamic relay neuron.

Although zinc ion (Zn2+) reduced the low-threshold T-type Ca2+ current of a rat thalamic relay neuron (TRN), we observed that Zn2+ increased a bursting activity of TRN by altering the generation and maintenance of low-threshold spike (LTS). Interestingly and importantly, Zn2+ shifted dramatically the voltage-dependence of both steady-state inactivation and activation of the transient A-type K+ current (I(A)) to a depolarizing direction. As I(A) is one of the main factors in shaping thalamic LTS, such alterations of gating properties of I(A) would contribute to the enhancement of TRN excitability under Zn2+. 2010 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.