Excitatory response of prefrontal cortical fast-spiking interneurons to ventral tegmental area stimulation in vivo

Synapse. 2006 Jun 1;59(7):412-7. doi: 10.1002/syn.20255.


Prefrontal cortical (PFC) pyramidal neurons (PN) and fast spiking interneurons (FSI) receive dopaminergic (DA) and non-DA inputs from the ventral tegmental area (VTA). Although the responses of PN to VTA stimulation and DA administration have been extensively studied, little is known about the response of FSI to mesocortical activation. We explored this issue using single and double in vivo juxtacellular recordings of medial PFC PN and FSI with chemical VTA stimulation. Electrophysiological characteristics combined with Neurobiotin staining and parvalbumin immunohistochemistry allowed identification of recorded cells as FSI or PN. NMDA injection into the VTA increased firing in all FSI tested (n = 7), whereas most PN (7/11) responded with an inhibition. Furthermore, FSI excitation matching the temporal course of PN inhibition was observed with FSI-PN paired recordings (n = 5). These divergent electrophysiological responses to mesocortical activation could reflect PFC GABAergic interneurons contributing to silencing PN. Thus, the mesocortical system could provide a critical control of PFC circuits by simultaneously affecting FSI and PN firing.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Animals
  • Excitatory Amino Acid Agonists / pharmacology
  • Interneurons / drug effects
  • Interneurons / physiology*
  • Male
  • N-Methylaspartate / pharmacology
  • Neural Inhibition / physiology
  • Neural Pathways / drug effects
  • Neural Pathways / physiology*
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / physiology*
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Stimulation, Chemical
  • Ventral Tegmental Area / drug effects
  • Ventral Tegmental Area / physiology*


  • Excitatory Amino Acid Agonists
  • N-Methylaspartate