title: Gain control of synaptic response function in cerebellar nuclear neurons by a calcium-activated potassium conductance.
abstract: Small conductance Ca(2+)-activated potassium (SK) current provides an important modulator of excitatory synaptic transmission, which undergoes plastic regulation via multiple mechanisms. We examined whether inhibitory input processing is also dependent on SK current in the cerebellar nuclei (CN) where inhibition provides the only route of information transfer from the cerebellar cortical Purkinje cells. We employed dynamic clamping in conjunction with computer simulations to address this question. We found that SK current plays a critical role in the inhibitory synaptic control of spiking output. Specifically, regulation of SK current density resulted in a gain control of spiking output, such that low SK current promoted large output signaling for large inhibitory cell input fluctuations due to Purkinje cell synchronization. In contrast, smaller nonsynchronized Purkinje cell input fluctuations were not amplified. Regulation of SK density in the CN therefore would likely lead to important consequences for the transmission of synchronized Purkinje cell activity to the motor system.
authors.affiliation: Department of Biology, Emory University, 1510 Clifton Rd., Atlanta, GA, 30322, USA.
authors.forename: Steven Si
authors.initials: SS
authors.lastname: Feng
authors.forename: Risa
authors.initials: R
authors.lastname: Lin
authors.forename: Volker
authors.initials: V
authors.lastname: Gauck
authors.forename: Dieter
authors.initials: D
authors.lastname: Jaeger
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002529:Cerebellar Nuclei / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*
chemical_list: D011188:Potassium; D002118:Calcium