Figure 10.

A: The firing response to hypercapnia (loose-cell patch in current clamp mode) of a neuron from the LC that contains rhodamine beads retrogradely labeled from the cNTS, the site of rhodamine bead injection. A1: The firing rate response to hypercapnic acidotic solution (15% CO₂) in the presence of aCSF; A2: The integrated firing rate (action potentials per 10 seconds) in normocapnic (5% CO₂) and hypercapnic (15% CO₂) solutions; B1: The firing rate response of the same neuron as in A to hypercapnic acidotic solution (15% CO₂) in the presence of synaptic block medium (SNB); B2: The integrated firing rate of the same neuron as in A in normocapnic (5% CO₂) and hypercapnic (15% CO₂) SNB solution. Note that hypercapnia reversibly decreased the firing rate of this LC neuron that projects to the cNTS even in the presence of SNB solution; C: Summary of the effect of hypercapnia in aCSF on firing rate (Hz: action potentials per s) in 3 rhodamine-labeled LC neurons; D: the reduction in firing rate by hypercapnia was maintained in SNB solution in the same rhodamine-labeled LC neuron shown in B.