Physiology of an ATP receptor in labellar sensilla of the tsetse fly Glossina morsitans morsitans Westw. (Diptera: Glossinidae).

Electrophysiological recordings have been made from cells in the eight large, labellar sensilla of g. morsitans. One of these cells in each sensillum was shown to respond to ATP over a concentration range of 10(-6)-10(-3) M. It was also sensitive to several other adenosine phophates, but much less sensitive to CTP, GTP and ITP. The activity of the receptor was depressed below pH 7, and sometimes considerably increased above pH 9. These aspects the receptor's physiology support the results of behavioural studies. It is concluded that the eight receptors mediate the flies' behavioural response to ATP.