Detlef H. Heck. Dept. of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN

Abstract:

Current evidence suggests that delta oscillations (0.5 – 4 Hz) in the brain are generated by intrinsic network mechanisms involving cortical and thalamic circuits. However, new observations in awake behaving mice show that delta band oscillations in spike and local field potential (LFP) activity in the whisker barrel cortex are phase-locked to respiration. Furthermore, LFP oscillations in the gamma frequency band (30 - 100 Hz) are amplitude modulated in phase with the respiratory rhythm. Removal of the olfactory bulb eliminates respiration-locked delta oscillations and delta-gamma phase amplitude coupling. Our findings thus suggest respiration-locked olfactory bulb activity as a main driving force behind delta oscillations and gamma power modulation in the awake mouse whisker barrel cortex (Ito et al. Nat. Commun. 2014, in press). Similar observations were made in motor and association cortical areas.