Synaptic exocytosis-related molecules (SNARE complex)

Generally, memory formation consists of synaptogenesis and a continuous increase in synaptic transmission in the neuronal network. However, little is known about the molecular mechanisms of synaptic transmission associated with olfactory imprinting and memory retrieval in the salmon brain. Exocytosis of pre-synaptic neurotransmitter vesicles is regulated by the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex. Synaptosome-associated protein-25 (SNAP-25), syntaxin-1 (STX-1), and vesicle associated membrane protein 2 (VAMP2)  constitute a SNARE complex, which regulates synaptic transmission and neuronal plasticity, and is associated with learning or memorization in mammals. Our present objective was to reveal the relationship between the expression of SNARE molecules and olfactory imprinting/memory retrieval in anadromous Pacific salmon. In this study, we analyzed expression changes during imprinting and/or memory retrieval periods for the natal stream using molecular biological techniques (quantitative PCR).