The effects of Triton-detergents on the stretch receptor of the crayfish

The effects of the non-ionic detergents Triton X-45 and Triton X-100 on the action potential and the receptor potential of the stretch receptor neuron of the crayfich Astacus fluviatilis was studied with intracellular recording technique. Membrane currents were measured with voltage clamp technique. Both detergents blocked the action potential in 20--30 min at concentrations of 60--80 microgram. Following blocking of spike electrogenesis the receptor potential evoked by strech was obtained in isolation. With prolonged exposure of the neuron to the detergents there was a slowly developing reduction of the receptor potential and after 60--90 min no response to stretch could be obtained. These effects were produced without any significant change of the resting membrane potential. Following return to normal saline the responsiveness to stretch was completely restored in 80--100 min. Measurements with voltage clamp techinque showed that the passive membrane properties were little affected by the two detergents. The stretch induced current on the other hand was severely depressed and almost abolished with prolonged exposure. The experimental results suggest that non-ionic detergents block the spike electrogenesis and the transducer action by a selective action on the sodium channels of the membrane of the receptor neuron.