Serotonin induces EPSCs preferentially in layer V pyramidal neurons of the frontal cortex in the rat

Cereb Cortex. 2000 Oct;10(10):974-80. doi: 10.1093/cercor/10.10.974.


The effect of serotonin (5-HT) on the release of glutamate was examined in pyramidal cells in layers II-VI of the frontal cortex. The intracellular recording electrode contained 1% biocytin so the neurons could later be visualized with an avidin-biotin peroxidase method. Pyramidal cells in layer V of the frontal cortex showed the greatest 5-HT-induced increase in both the frequency and amplitude of 'spontaneous' (non-electrically evoked) excitatory post-synaptic currents (EPSCs). A small proportion of neurons in layer II/III showed an increase in EPSC frequency, whereas cells in layer VI showed no significant change in either EPSC frequency or amplitude. The physiological response to 5-HT mirrors the high density of 5-HT(2A) receptors in layer V, as well as the pattern of thalamic projections in frontal cortex. The specific induction of EPSCs in layer V neurons suggests that 5-HT preferentially modulates the output neurons of the frontal cortex.

Publication types

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

MeSH terms

  • Animals
  • Electrophysiology
  • Excitatory Postsynaptic Potentials / drug effects*
  • Frontal Lobe / drug effects*
  • Frontal Lobe / physiology*
  • Histocytochemistry
  • In Vitro Techniques
  • Lysine / analogs & derivatives*
  • Male
  • Osmolar Concentration
  • Pyramidal Cells / drug effects*
  • Pyramidal Cells / physiology*
  • Rats
  • Serotonin / pharmacology*


  • Serotonin
  • biocytin
  • Lysine