Low-threshold calcium currents in central nervous system neurons.
The low-threshold calcium current, or T current, has recently been demonstrated with voltage-clamp recordings in a variety of central nervous system (CNS) neurons. It is especially prominent in the soma and dendrites of neurons with robust calcium-dependent burst firing behaviors such as thalamic relay neurons and cerebellar Purkinje cells. Single-channel and macroscopic current behavior have been carefully investigated and kinetic schemes devised to completely describe the activation and inactivation processes. The kinetic properties of T current lead to activation of low-threshold spikes subsequent to transient membrane hyperpolarizations. Putative functional roles for T current include generation of low-threshold spikes that lead to burst firing, promotion of intrinsic oscillatory behavior, boosting of calcium entry, and synaptic potentiation.
Huguenard
J R
JR
Department of Neurology and Neurological Sciences, Stanford University School of Medicine, California 94305, USA.
D000818:Animals; D002120:Calcium Channel Agonists / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism*; D002490:Central Nervous System / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*
D002120:Calcium Channel Agonists; D002121:Calcium Channel Blockers; D015220:Calcium Channels