Climbing fiber activation of metabotropic glutamate receptors on cerebellar purkinje neurons

Neuron. 2002 Dec 19;36(6):1159-67. doi: 10.1016/s0896-6273(02)01052-8.

Abstract

In the cerebellum, metabotropic glutamate receptors (mGluRs) are required for distinct forms of synaptic plasticity expressed at parallel fiber (PF) and climbing fiber (CF) synapses. At PF synapses, mGluR activation generates a slow synaptic current and triggers intracellular calcium release; at CF synapses, mGluR activation has not been observed. This has led some investigators to propose that mGluR-dependent changes in CF synaptic strength are induced heterosynaptically. Here we describe an mGluR-mediated response to CF stimulation consisting of two parallel signaling pathways: one leading to a slow synaptic conductance and the other leading to internal calcium release. This additional target for glutamate broadens the signaling capabilities of CF synapses and raises the possibility that changes in CF strength are homosynaptically triggered.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / physiology
  • Amino Acid Transport System X-AG / drug effects
  • Amino Acid Transport System X-AG / metabolism
  • Animals
  • Animals, Newborn
  • Calcium / metabolism
  • Calcium Signaling / drug effects
  • Calcium Signaling / physiology
  • Electric Stimulation
  • Excitatory Amino Acid Antagonists / pharmacology
  • Excitatory Postsynaptic Potentials / drug effects
  • Excitatory Postsynaptic Potentials / physiology
  • Glutamic Acid / metabolism
  • Neural Pathways / drug effects
  • Neural Pathways / growth & development
  • Neural Pathways / metabolism*
  • Olivary Nucleus / drug effects
  • Olivary Nucleus / growth & development
  • Olivary Nucleus / metabolism*
  • Presynaptic Terminals / drug effects
  • Presynaptic Terminals / metabolism*
  • Purkinje Cells / cytology
  • Purkinje Cells / metabolism*
  • Rats
  • Receptors, AMPA / drug effects
  • Receptors, AMPA / metabolism
  • Receptors, Glutamate / drug effects
  • Receptors, Glutamate / metabolism*
  • Receptors, Metabotropic Glutamate / drug effects
  • Receptors, Metabotropic Glutamate / metabolism
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology*
  • Up-Regulation / drug effects
  • Up-Regulation / physiology

Substances

  • Amino Acid Transport System X-AG
  • Excitatory Amino Acid Antagonists
  • Receptors, AMPA
  • Receptors, Glutamate
  • Receptors, Metabotropic Glutamate
  • Glutamic Acid
  • Calcium