Opposing effects of an atypical glycinergic and substance P transmission on interpeduncular nucleus plasticity.

ABSTRACT: The medial habenula-interpeduncular nucleus (MHb-IPN) pathway has recently been implicated in the suppression of fear memory. A notable feature of this pathway is the corelease of neurotransmitters and neuropeptides from MHb neurons. Our studies in mice reveal that an activation of substance P-positive dorsomedial habenula (dMHb) neurons results in simultaneous release of glutamate and glycine in the lateral interpeduncular nucleus (LIPN). This glycine receptor activity inhibits an activity-dependent long-lasting potentiation of glutamatergic synapses in LIPN neurons, while substance P enhances this plasticity. An endocannabinoid CB1 receptor-mediated suppression of GABA_B receptor activity allows substance P to induce a long-lasting increase in glutamate release in LIPN neurons.

SUBMITTER: Melani R 

PROVIDER: S-EPMC6785085 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature