STATIC AND DYNAMIC PROPERTIES OF WARM FIBRES IN INFRAORBITAL NERVE

Specific warm receptors in the nasal region of cats show a static discharge at constant temperatures between 30 and 48°C. The frequency of single fibres rises steeply with temperature, reaches a maximum between 45 and 47°C and then falls to zero. Rapid warming causes an overshoot, rapid cooling a transient inhibition of the warm fibre discharge. Below the static threshold, dynamic reponses can still be elicited. The dynamic maximum frequency increases with the adapting temperature and with the amount of temperature change. Dynamic and static differential sensitivities depend also on temperature, the dynamic values being several times higher than the static ones. At high temperatures, slow linear cooling causes a decrease but no complete inhibition of the continuous warm fibre discharge. © 1969 Springer-Verlag.