Peripheral thermal sensitivity in the rabbit.

KLUGER, MATTHEW J., RICHARD R. GONZALEZ, AND JAMES D. HARDY. Peripheral thermal sensitivzty in the rabbit. Am. J. Physiol. 222(4): 1031-1034. 1972.-Selective warming of the ears of the New Zealand white rabbit at ambient temperature (TEL) of 8 C led to a decline in metabolism (M) and no significant change in hypothalamic temperature (Thy). After ear warming was discontinued, M increased. Conversely, cooling the ears of these rabbits at T, = 17 C led to an increase in M and no change in Thy. After ear cooling was discontinued, M decreased. Heating a small area of the back of these rabbits (at T, = 8 C) led to a decline in M, followed by a rise in M on termination of heating. The effects of heating the skin beneath the heavy fur of the back and the skin of the ears, expressed as change in M per “C per unit area, were similar. Under natural conditions the sparsely furred ear is more subject to temperature fluctuations than is the heavily furred back, thus, the ears are probably of greater importance in the thermal responses of the rabbit than is the heavily furred skin. An attempt was made to estimate the effect of peripheral heating in the rabbit assuming a summative model, but such a model leads to a thermal response greater than actually measured. Therefore, we conclude that the physiological response to peripheral heating in the rabbit is not the result of a simple addition of effects from several areas.