The effect of aerobic exercise on the capacity of working memory after olfactory sensory destruction

Nasal breathing has many health benefits, especially in exercise. Airflow through the nose stimulates the Olfactory Bulb during the breathing cycle, associated with the airflow intensity. This information reaches the Olfactory Bulb and causes oscillations that transfer to the prefrontal cortex, hippocampal formation, and other brain areas. Brain rhythms have been associated with different cognitive states and play functional roles in network computation, such as memory. Accordingly, this study investigates the effect of aerobic exercise on capacity of working memory following Olfactory sensory neurons destruction.In this study, we used sixteen male Wistar rats (۱۲-۱۴ weeks, weighing ۲۵۰-۳۰۰ g). After implanting an electrode in the Olfactory Bulb and hippocampus for Local Field Potential recording, animals were divided into two exercises and two control groups. At the beginning of each week, one exercise group and one control group, to destroy the Olfactory sensory neurons, received ۳۰۰ mg/kg methimazole. After completing the exercise protocol (۵ days/ week for ۷ weeks), we simultaneously recorded Local Field Potential from rat hippocampus and Olfactory Bulb during a Y-maze working memory task.Result: methimazole injection significantly reduced the working memory and power of Delta and Theta frequencies, and exercise could prevent this decline and improve working memory. Also, Olfactory Bulb oscillations at Delta and Theta frequency ranges are significantly coherent with hippocampus activity in the correct trials in the control methimazole group (p<۰.۰۵).it seems that working memory capacity is limited and in healthy or trained subjects cannot be improved through the training. However, when the working memory is impaired, exercise can have compensated effects and improve working memory.

کلیدواژه ها:

aerobic exercise ، Working memory ، Nasal breathing ، local field potentials