Type 3 adenylyl cyclase in the MOE is involved in learning and memory in mice

Although olfactory dysfunction is related to learning and memory impairment, the causal relationship between main olfactory epithelium (MOE) disruption and learning and memory is still unknown. The present study aimed to establish whether MOE disruption causes learning and memory impairment and whether the expression of type 3 adenylyl cyclas (AC(3)) in the MOE is related to learning and memory. First, the buried food test was carried out to confirm that MOE function was disrupted in mice treated with nasal instillation of zinc sulfate (ZnSO4 mice), and mice with specific knockdown of AC(3) in the MOE by CRISPR/Cas9 technology (AC(3KD/MOE) mice). Then, behavioural tasks associated with learning and memory were administered. ZnSO4 mice and AC(3KD/MOE) mice showed impairments in learning and memory tests, including the novel object recognition test, the step-down passive avoidance test, the Morris water maze test, and the Y-maze test. Our data demonstrate that MOE disruption caused by nasal exposure to ZnSO4 or specific knockdown of AC(3) in the MOE resulted in learning and memory impairment, and they further demonstrate that the expression of AC(3) in the MOE plays a major role in learning and memory.