Long-term synaptic plasticity in cerebellar stellate cells.
Inhibitory transmission controls the action potential firing rate and pattern of Purkinje cell activity in the cerebellum. A long-term change in inhibitory transmission is likely to have a profound effect on the activity of cerebellar neuronal circuits. However, little is known about how neuronal activity regulates synaptic transmission in GABAergic inhibitory interneurons (stellate/basket cells) in the cerebellar cortex. We have examined how glutamate released from parallel fibers (the axons of granule cells) influences postsynaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors in stellate cells and modulates gamma-aminobutyric acid (GABA) release from these neurons. First, we found that burst stimulation of presynaptic parallel fibers changes the subunit composition of post-synaptic AMPA receptors from GluR2-lacking to GluR2-containing receptors. This switch reduces the Ca(2+) permeability of AMPA receptors and the excitatory postsynaptic potential amplitude and prolongs the duration of the synaptic current, producing a qualitative change in synaptic transmission. This switch in AMPA receptor phenotype can be induced by activation of extrasynaptic N-methyl-D: -aspartate (NMDA) receptors and involves PICK1 and the activation of protein kinase C. Second, activation of presynaptic NMDA receptors triggers a lasting increase in GABA release from stellate cells. These changes may provide a cellular mechanism underlying associative learning involving the cerebellum.
Department of Biology, Penn State University, University Park, PA 16802, USA. sjl16@psu.edu
Siqiong June
SJ
Liu
Philippe
P
Lachamp
Yu
Y
Liu
Iaroslav
I
Savtchouk
Lu
L
Sun
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001245:Association Learning / Q000502:physiology*; D002531:Cerebellum / Q000502:physiology*; D006801:Humans; D007395:Interneurons / Q000187:drug effects / Q000502:physiology*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008322:Mammals; D009473:Neuronal Plasticity / Q000187:drug effects; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D018091:Receptors, AMPA / Q000502:physiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D005680:gamma-Aminobutyric Acid; C104722:glutamate receptor ionotropic, AMPA 2