Challenging a decades-old model of non-synaptic transmission of acetylcholine, we show that all hippocampal cholinergic terminals establish GABAergic synapses. We demonstrate that these synapses co-transmit GABA and acetylcholine via different vesicles, whose release is triggered by distinct calcium channels. This co-transmission evokes composite postsynaptic potentials, which are mutually cross-regulated by presynaptic autoreceptors. The GABAergic component alone effectively suppresses hippocampal sharp wave-ripples and epileptiform activity. This differentially regulated co-transmission suggests a hitherto unrecognised level of control over cortical states.
Full article: https://www.nature.com/articles/s41467-018-05136-1