Fig. 6. The physiological response of chick trigeminal ganglion neurons to methyl anthranilate (MA) was also dependent on extracellular sodium, but responses to capsaicin (CAP) were not. (A) The response of a neuron that did not respond to MA when extracellular sodium was removed. The response returned when sodium was re-introduced. (B) A capsaicin-induced increase in intracellular Ca²⁺ even in the absence of extracellular Na⁺.