Abstract
INTRODUCTION: The positive effects of exercise on spatial memory and learning have been demonstrated in research. The olfactory sensory neurons (OSNs) respond to mechanical stimulation induced by nasal airflow which is associated with airflow intensity. Accordingly, nasal breathing can modulate brain oscillations in nonolfactory areas, and respiration-entrained oscillations aid the improvement of cognitive abilities. Given that aerobic exercise increases the rate of respiration and intensity of nasal airflow, this study evaluates the role of OSNs in mediating the effects of aerobic exercise on memory. METHODS: We examined spatial memory following exercise in animal models of olfactory sensory neuron impairment (methimazole injection 300 mg/kg/week). RESULTS: Destroying OSNs significantly reduces olfactory bulb (OB) activity at delta and theta frequency bands as well as its coupling to respiration. More importantly, it abolished the positive effect of exercise on spatial memory (P<0.05). CONCLUSION: The OB activity is one of the probable mechanisms for improving spatial memory following exercise.