Python pit organs analyzed as warm receptors.

The infrared receptor neurons of Python reticulatus pit organs were all found to have bimodal sensitivity, responding to both infrared and touch stimuli with fairly rapid adaptation. The majority (22 of 29 neurons) had no background discharges at any temperature between 20 and 33 degrees C. The receptive areas were 150-250 micrometers in diameter and identical for both modalities. There was only one receptive area for each neuron. These facts suggest the possibility that some kinds of temperature sensitive neurons can also function as touch neurons and vice versa, not only in this species, but also in other animals.