Figure 1: Oscillatory neuronal activity phase locks with breathing.

Correlation and coherence between respiratory and local field potential (LFP) signals in barrel cortex in an awake mouse. Data from one mouse are shown, but results were reproduced in five out of five mice. (a) Respiratory rhythm (black) and two LFP signals simultaneously recorded in the whisker barrel cortex (red and blue) at rest. Recording sites were 300 μm apart. (b) Autocorrelations (left) of respiratory and LFP signals and LFP-respiration cross-correlations (right). Curve colours correspond to those in a. (c) Same recordings as in a, but during accelerated breathing induced by brief exposure to hypoxic air. (d) Autocorrelations (left) of respiratory and LFP signals and LFP-respiration cross-correlations (right). Curve colours correspond to those in a. (e) Instantaneous respiration frequency (top) and LFP-respiration coherency (bottom) during normal accelerated breathing elicited by exposure to hypoxic air. Respiration frequency and coherency were computed within 5-s time windows, moved in 2.5-s steps. The coherence was plotted in a pseudo-colour code shown on the right. Grey background in top panel indicates time of exposure to hypoxic air. Data shown in a and c are two 3-s segments of the full data range shown in e (the time axes in a and c are common with the one in e).