Presynaptic gating of excitation in the dorsal raphe nucleus by GABA

SOIZA-REILLY M; ANDERSON WB; VAUGHAN CW; COMMONS KG

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

NATL ACAD SCIENCES

Lugar: Washington DC, USA; Año: 2013 vol. 110 p. 15800 - 15805

0027-8424

The dorsal raphe nucleus (DR) controls forebrain serotonin neurotransmission to influence emotional states. GABA neurotransmission in the DR has been implicated in regulating sleep/wake states and influencing anxiety and aggression. To gain insight into how GABA regulates DR activity, we analyzed the organization of both GABA and glutamate axons in the rat DR using a high-resolution immunofluorescence technique, array tomography, as well as EM. This analysis revealed that a third or more of GABA-containing axons are organized in synaptic triads with a glutamatergic axon and a common postsynaptic target. Electrophysiological recordings showed that GABA has the capacity to presynaptically gate glutamate release in the DR through a combination of GABA-A and GABA-B receptor-mediated effects. Thus, GABA-glutamate synaptic triads are a common feature of the network architecture of the DR with the potential to regulate excitation of the nucleus.