CNI chalk talk: Andrew Moberly

Andrew Moberly, 4th year student working with Minghong Ma

Respiration-entrained activity in olfactory and non-olfactory brain regions

Oscillatory dynamics in populations of cortical and subcortical neurons are believed to serve critical roles in sensory information processing, motor coordination, and learning and memory. However, the source of oscillations is elusive in many cases. A respiration entrained oscillation is a hallmark of rodent olfactory areas including the olfactory bulb and olfactory cortices. This oscillation follows respiratory rates from resting breathing (2-4 Hz) to fast sniffing (up to 12 Hz). Olfactory sensory neurons (OSNs) in the nose are sensitive to mechanical stimulation and can relay inspiration and expiration information throughout the olfactory system. Curiously, respiration-entrained activity has also been observed in non-olfactory areas. To determine if OSNs play a role in generating oscillatory dynamics in other brain regions, we monitored respiration and local field potentials in various brain regions (e.g. the whisker barrel cortex, hippocampus, and medial prefrontal cortex) under different conditions in freely behaving animals. Preliminary results show that the local field potentials from these brain regions are entrained by respiration during normal breathing but less so when the olfactory epithelium is ablated. Since the neuronal events that underlie behaviors are embedded in these population rhythms, we are currently testing the hypothesis that respiration influences neural oscillations during specific natural behaviors.