Distinct release properties of glutamate/GABA co-transmission serve as a frequency-dependent filtering of supramammillary inputs.

ABSTRACT: Glutamate and GABA co-transmitting neurons exist in several brain regions; however, the mechanism by which these two neurotransmitters are co-released from the same synaptic terminals remains unclear. Here, we show that the supramammillary nucleus (SuM) to dentate granule cell synapses, which co-release glutamate and GABA, exhibit differences between glutamate and GABA release properties in paired-pulse ratio, Ca²⁺-sensitivity, presynaptic receptor modulation, and Ca²⁺ channel-vesicle coupling configuration. Moreover, uniquantal synaptic responses show independent glutamatergic and GABAergic responses. Morphological analysis reveals that most SuM terminals form distinct glutamatergic and GABAergic synapses in proximity, each characterized by GluN1 and GABA_A

SUBMITTER: Hirai H 

PROVIDER: S-EPMC11649240 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature