Electrophysiological investigation of chemoreceptors of the maxillary palps of Locusta migratoria migratorioides R. et F. I. General characteristics of receptor responses evoked by NaCl stimulation.

Following stimulation with NaCl of different concentrations, responses from one, two or three receptor cells of the sensillae could be recorded, one of them being always "dominant". The other one or two secondary cells showed a lower frequency and a faster adaptation. The responses of the dominant cells proved to be variable, even to repeated stimulations using the same concentration of the same substance. Increasing the concentration from 0.01 mol/l to 1.0 mol/l, the initial frequency may increase or decrease, however, frequency minimum or maximum may also occur at an intermediate concentration. These findings indicate a less specialized stage of the receptor cells. The individual characteristics of the receptor cells may be surpassed when averaging the responses of sufficiently high number of cells.