Fig 8. Photostimulation in the BötC region causes excitation of BötC post-I and aug-E neuron activity and inhibition of inspiratory neuron activity in the pre-BötC in situ.

(A) Extracellular recordings from post-I type expiratory neurons in the BötC showing example of tonic excitation of neuron activity during laser application to the BötC (2 mW) along with complete inhibition of inspiratory phrenic nerve activity (PN) in the arterially-perfused in situ brainstem-spinal cord preparation from adult VGAT-ChR2 transgenic mice. (B) Extracellular recordings from aug-E type expiratory neurons in the BötC also showing excitation of neuron activity during laser illumination (2 mW) of the BötC region, which reduced the frequency of inspiratory activity in this example. (C) Extracellular recordings from inspiratory (pre-I/I) neuron activity in the pre-BötC illustrating inhibition of PN inspiratory activity by 2 mW laser illumination in the BötC region. Black dashed lines indicate the end of inspiratory phase activity of PN in A, but indicate the onset of inspiratory phase activity of PN in B and C. The lower traces indicate the duration and amplitude of the laser stimulation.