Neural excitability, synaptic transmission and neuron-glia interactions
Author: Claudia Mosquera | Email: ClaudiaMosquera23@uba.ar
Claudia Mosquera1°2°, Joaquín Piriz1°
1° Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), UBA-CONICET, Buenos Aires, Argentina
2° Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, UBA
The lateral habenula (LHb) is an epithalamic nucleus involved in mood disorders. The LHb is the only consistently characterized brain structure that is targeted by synapses that co-transmits GABA and glutamate (co-transmitting synapses). These synapses originate in at least two LHb upstream structures. However, recent works suggest many LHb innervating structures generate co-transmitting synapses.
In this work we seek to investigate properties of GABAergic component of co-transmitting synapses and comparing it with GABAergic inputs to the LHb. We performed patch-clamp recordings from the LHb in brain slices. To study the GABAergic component of co-transmission we used a transgenic mice Ai32::Vglut2-ires-cre in which ChR2(H134R) is directed to Vglut2 positive neurons. To study the GABAergic inputs to the LHb we injected Cre in mainly GABAergic structures of transgenic mice with Cre dependent ChR2. In both cases synaptic currents were evoked by light stimulation of axonal terminals at the LHb, and pharmacologically isolated the GABAergic component were adding CNQX and APV to the recording solution.
Consistently with what is reported, we observed GABAergic synaptic currents in Ai32::Vglut2-ires-cre mice. Moreover, GABAergic responses were detected in the majority of LHb recorded neurons supporting the generality of co-transmission.