Séminaire d’Emmanuel Valjent

Vendredi 12 juin 2026, à 11h00 – Salle Henri Gastaut, INT

Emmanuel Valjent (Institut des neurosciences de Montpellier) invité par Corinne Beurrier

Midbrain dopamine D2R signaling regulates motivated behaviors

Abstract: Midbrain dopamine (DA) neurons act as intrinsic pacemakers that sustain basal extracellular dopamine levels through continuous firing. Dopamine D2 autoreceptors (autoD2Rs) exert inhibitory feedback by modulating DA neuron excitability and dopamine release, while the non-selective sodium leak channel NALCN has been proposed as a major regulator of this inhibitory mechanism. However, the behavioral and neurophysiological consequences of NALCN loss within DA neurons remain unclear. Using conditional knockout mouse models (Drd2Slc6a3 and NalcnSlc6a3), we examined how selective deletion of either Drd2 or Nalcn in midbrain DA neurons affects neuronal activity, D2R-mediated signaling at DA terminals, reactivity to cues-predicting threat and psychostimulants responsiveness in both male and female. Our data study reveal sex-biased dissociable roles of NALCN and autoD2Rs in regulating DA-dependent behaviors, providing mechanistic insight into dopaminergic modulation underlying reward and threat processing.