Fig. 5.

Individual spiking local interneurons respond to stimulation with different chemicals. The response characteristics of different local interneurons were all similar when tested with different chemicals at fixed concentrations. Neurons were repeatedly tested with single concentrations of four different chemicals at 2 min intervals. A, In experiments where significant differences in response duration occurred, interneurons always responded most strongly to 5 mm NHT and 250 mmNaCl than to 250 mm sucrose and water. Eachsymbol/line represents data from a different interneuron.B, Typical recordings of the responses obtained during an experiment showing the longer-duration responses to NHT and NaCl. Five responses to each test chemical are superimposed. Note the consistency of the responses to each test chemical.