... receptor. Fish were equipped with opercular, branchial and snout cannulae for measurements of cardiorespiratory parameters and drug injections. Oxygen chemoreceptor reflexes were evoked by rapid hypoxia, NaCN added into the blood(internal, 0.3 ml, 50 μgml –1 ) and the mouth (external, 0.5 ml, 1 mg ml –1...

... (NaCN) in the water flowing over the gills stimulated bradycardia, and gill and air ventilation in sham-operated fish. Sodium cyanide, noradrenaline (NA) and adrenaline (A) infusion into the dorsal aorta increased gill ventilation, and NA and A infusion also stimulated tachycardia and an increase...

... branches of cranial nerve X to the four gill arches (Xb 1 –Xb 4 ). Cardiovascular and ventilatory responses to hypoxia and NaCN were attenuated by partial denervation of the gills. There were no significant cardiovascular or ventilatory reflex responses to either hypoxia or NaCN after total branchial...