Electrophysiological analysis of responses of adult females of Brugia pahangi to some chemicals

Electrophysiological techniques were used to obtain recordings of extracell ular electrical activity from the anterior end of live adult females of Bru gia pahangi. Stimulation with 100 mM, 10 mM and 1 mM acetylcholine resulted in an increase in spike activity which was concentration dependent, wherea s stimulation with phosphate-buffered saline and 0.1 mM acetylcholine gave no increase in activity. The delay in response was not concentration depend ent. The action of possible host cues was investigated. Stimulation with he al-inactivated foetal calf serum (IFCS) and 10 mM glutathione gave an incre ase in spike activity but exposure to 5 mg/dl haemoglobin elicited no respo nse. The response to IFCS was found to be suppressed completely by pre-incu bation for 30 min in ivermectin.