Effects of temperature and deuterium oxide on crustacean stretch receptor

1. The receptor potential was recorded intracellularly from the isolated stretch receptor neuron of crayfish. Total substitution of D2O for H2O in the bathing solution reversibly decreased the amplitude of the receptor potential to a level of 34% of the control. The input resistance of the neuron was slightly increased by the D2O treatment, while the resting potential and the input capacity were virtually unchanged. The viscoelastic property of the receptor muscle was not altered by the D2O substitution. Thus, D2O seems to inhibit directly the activation process of the receptor potential. 2. Temperature change over the range of 25-5 degrees C did not affect the amplitude of receptor potential. However, the input resistance of the neuron was increased about twofold by the lowering of temperature from 25 to 5 degrees C. 3. We conclude that when the temperature is lowered, the receptor current is diminished, but this decline is just about compensated for by the increase in membrane resistance, resulting in a near constancy of the receptor potential. This is the cellular basis for the relative constancy of the transduction process of the stretch receptor in the face of large temperature changes. On the other hand, in the case of D2O substitution the compensation mechanism of the resistance increase does not work, and the sensory transduction is inhibited substantially.