Long-term Potentiation Induces Expanded Movement Representations and Dendritic Hypertrophy in Layer V of Rat Sensorimotor Neocortex

Marie H. Monfils, Penny M. VandenBerg, Jeffrey A. Kleim, G. Campbell Teskey

Research output: Contribution to journalArticle

103 Scopus citations

Abstract

While long-term potentiation (LTP) is currently the most widely investigated model of the synaptic mechanisms underlying learning, there is a paucity of reports on the direct effects of LTP on cortical organization. Here we show that strengthening polysynaptic potentiation correlates with an expanded neocortical area that responds to intracortical microstimulation-induced movements of rat forelimb and increased dendritic material in layer V pyramidal cells. Rats carried a stimulating electrode in the corpus callosum (midline), and a recording electrode in the right caudal forelimb area (CFA). Each rat received 15 days of either high frequency stimulation (HFS) or handling. Evoked potentials of the transcallosal pathway were recorded in the right hemisphere before and after 15 days of stimulation or handling. Following the last stimulation, movement representations were determined in the left CFA using high-resolution intracortical microstimulation (ICMS) and then the brains were processed for Golgi-Cox staining. Our results show that synaptic modification results in a recruitment of more neocortical area into movement representations and increases in several measures of dendritic morphology in layers III and V. This study sheds light on the interaction between artificial models of learning, receptive field characteristics and dendritic morphology in the sensorimotor cortex.

Original languageEnglish (US)
Pages (from-to)586-593
Number of pages8
JournalCerebral Cortex
Volume14
Issue number5
DOIs
StatePublished - May 1 2004
Externally publishedYes

    Fingerprint

Keywords

  • Caudal forelimb area
  • Dendritic morphology
  • Golgi-Cox
  • Long-term potentiation
  • Motor cortex reorganization
  • Neocortex

ASJC Scopus subject areas

  • Cognitive Neuroscience
  • Cellular and Molecular Neuroscience

Cite this