BREATHING-COUPLED OSCILLATIONS IN THE CORTICOLIMBIC REGION ACROSS EMOTIONAL STATES

Nasal breathing provides a rhythmic physiological signal that can structure neuronal activity beyond odor sampling. Despite the well-known relation between emotions and breathing patterns, it is unknown how emotional context modulates breathing- coupled oscillations in the mammalian brain. Here we studied how emotional valence shapes the extent of breathing-linked coordination of neuronal activity in corticolimbic circuits of mice. We monitored breathing from olfactory epithelium activity and simultaneously recorded local field potentials (LFP) from olfactory bulb (OB), medial prefrontal cortex, dorsal and ventral hippocampus, and basolateral amygdala while mice freely explored an open field (10 min) in the presence of an aversive odor (TMT), a positive social odor (female urine), or a neutral control (distilled water) presented in the center of the arena. Behaviorally, mice preferred the positive odor, whereas TMT led to avoidance of the scented region and increased immobility.
Breathing was slower and substantially more regular in the aversive condition, contrasting with a bimodal pattern (alternating slow and fast breathing) in the neutral and positive conditions. Across regions, power spectra and coherence measures revealed robust breathing-coupled LFP oscillations whose strength and frequency content varied with odor valence. Notably, the aversive odor enhanced corticolimbic coherence in the 3–5 Hz range, consistent with the ~4-Hz breathing-linked rhythm previously associated with freezing in fear-conditioning paradigms. To investigate underlying mechanisms, we are acquiring data using transient OB suppression via
inhibitory DREADDs to quantify changes in breathing coupling. These findings support a context-dependent expression of breathing-related corticolimbic synchrony.