Enhanced amygdala kindling after electrical stimulation of the ventral tegmental area: implications for fear and anxiety

J Neurosci. 1999 Nov 15;19(22):RC41. doi: 10.1523/JNEUROSCI.19-22-j0004.1999.

Abstract

Electrical kindling refers to the seizure-generating properties of brain stimulation. In addition to producing epilepsy, the reorganization of forebrain neurocircuitry associated with kindling contributes to psychiatric disturbances involving fear and anxiety. The amygdala is a limbic structure that kindles readily and regulates the complex neurocircuitry underlying emotional responding. Dopamine-containing ventral tegmental area (VTA) neurons, known to be activated by threatening environmental stimuli, are an important component of the amygdala-based fear network. Using amygdala kindling as an indicator of sensitization development, we report here that repeated low-current, high-frequency stimulation of the VTA provoked afterdischarge in the central amygdala and enhanced kindling rate. By establishing a fundamental link between VTA activation and neural excitability in the central amygdala, the present results are consistent with the possibility of a common process underlying epileptogenisis and the fear motivational consequences of amygdala and VTA kindling. Considering the established role of the VTA and the amygdala in emotional responding, such a sensitization mechanism might mediate exaggerated fearfulness.

Publication types

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

MeSH terms

  • Amygdala / anatomy & histology
  • Amygdala / physiology*
  • Animals
  • Anxiety / physiopathology*
  • Electric Stimulation
  • Electroencephalography
  • Fear / physiology*
  • Kindling, Neurologic*
  • Male
  • Rats
  • Rats, Wistar
  • Ventral Tegmental Area / anatomy & histology
  • Ventral Tegmental Area / physiology*