Serotonin induces EPSCs preferentially in layer V pyramidal neurons of the frontal cortex in the rat.
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.
Lambe
E K
EK
Interdepartmental Neuroscience Program, Section of Neurobiology, and Departments of Psychiatry and Pharmacology, Yale University School of Medicine, New Haven, CT, USA. evelyn.lambe@yale.edu
Goldman-Rakic
P S
PS
Aghajanian
G K
GK
D000818:Animals; D004594:Electrophysiology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects*; D005625:Frontal Lobe / Q000187:drug effects* / Q000502:physiology*; D006651:Histocytochemistry; D066298:In Vitro Techniques; D008239:Lysine / Q000031:analogs & derivatives*; D008297:Male; D009994:Osmolar Concentration; D017966:Pyramidal Cells / Q000187:drug effects* / Q000502:physiology*; D051381:Rats; D012701:Serotonin / Q000494:pharmacology*
D012701:Serotonin; C013411:biocytin; D008239:Lysine