noun
synaptic cleft
The narrow gap between a presynaptic and postsynaptic neuron where neurotransmitters are released.
神経伝達物質はシナプス間隙に放出される。
Neurotransmitters are released into the synaptic cleft.
シナプス refers to the entire synapse, while シナプス間隙 specifically denotes the gap within the synapse.
Compound of シナプス (synapse) and 間隙 (gap, cleft). シナプス is from English 'synapse', and 間隙 is a Sino-Japanese word.