Loss of synaptic depression in mammalian anterior cingulate cortex after amputation

J Neurosci. 1999 Nov 1;19(21):9346-54. doi: 10.1523/JNEUROSCI.19-21-09346.1999.

Abstract

Two forms of activity-dependent long-term depression (LTD) in the CNS, as defined by their sensitivity to the blockade of NMDA receptors, are thought to be important in learning, memory, and development. Here, we report that NMDA receptor-independent LTD is the major form of long-term plasticity in the anterior cingulate cortex (ACC). Both L-type voltage-gated calcium channels and metabotropic glutamate receptors are required for inducing LTD. Amputation of a third hindpaw digit in an adult rat induced rapid expression of immediate early genes in the ACC bilaterally and caused a loss of LTD that persisted for at least 2 weeks. Our results suggest that synaptic LTD in the ACC may contribute to enhanced neuronal responses to subsequent somatosensory stimuli after amputation.

Publication types

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

MeSH terms

  • 6-Cyano-7-nitroquinoxaline-2,3-dione / pharmacology
  • Amputation, Surgical
  • Animals
  • Calcium Channels, L-Type / physiology
  • Cyclic AMP Response Element-Binding Protein / genetics
  • DNA-Binding Proteins / genetics
  • Early Growth Response Protein 1
  • Electric Stimulation
  • Enkephalin, D-Penicillamine (2,5)- / pharmacology
  • Evoked Potentials / drug effects
  • Excitatory Postsynaptic Potentials / drug effects
  • Functional Laterality
  • Gene Expression Regulation
  • Gyrus Cinguli / drug effects
  • Gyrus Cinguli / physiology*
  • Hindlimb
  • Immediate-Early Proteins / genetics
  • In Vitro Techniques
  • Male
  • Neuronal Plasticity / drug effects
  • Neuronal Plasticity / physiology*
  • Neurons / drug effects
  • Neurons / physiology*
  • Picrotoxin / pharmacology
  • Proto-Oncogene Proteins c-fos / genetics
  • Rats
  • Rats, Sprague-Dawley
  • Reaction Time
  • Receptors, Metabotropic Glutamate / physiology
  • Synapses / drug effects
  • Synapses / physiology*
  • Toes / innervation*
  • Transcription Factors / genetics

Substances

  • Calcium Channels, L-Type
  • Cyclic AMP Response Element-Binding Protein
  • DNA-Binding Proteins
  • Early Growth Response Protein 1
  • Egr1 protein, rat
  • Immediate-Early Proteins
  • Proto-Oncogene Proteins c-fos
  • Receptors, Metabotropic Glutamate
  • Transcription Factors
  • Picrotoxin
  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • Enkephalin, D-Penicillamine (2,5)-