Fig. 3.

GFP-LC neuron stimulated by hypercapnic acidosis (HA). A: membrane potential (Em) of a GFP- LC neuron stimulated by HA. Top: hypocapnic alkalosis (3% CO₂, pH ∼7.6). Middle: control (5% CO₂, pH ∼7.4). Bottom: HA (9% CO₂, pH 7.2). The mean FRs (in Hz) were 1.01 during alkalosis, 1.82 in control solution, and 3.02 during acidosis. B: simultaneous recordings of FR (top) and extracellular bath pH (bottom) induced by alterations in CO₂. C: this LC neuron was visualized with both fluorescence microscopy (top) and Normaski DIC optics (bottom). Scale bar, 50 μm.