Facilitation of thermoregulatory heating behavior by single cortical spreading depression in the rat

Effects of single waves of unilateral cortical spreading depression (CSD) on skin-heating behavior were studied in the rat with the unilateral lesion in the preoptic and anterior hypothalamus (PO/AH). A single CSD contralateral to the PO/AH lesion significantly increased the number of heating for 4 min after CSD had entered the frontal cortex with a maximum facilitation rate 20% above the pre-CSD level. On the other hand, a single CSD ipsilateral to the PO/AH lesion slightly augmented the number of heating for 2 min with a maximum increase of 8% above the pre-CSD level. An injection of 0.9% NaCl (non-CSD trial) did not affect the skin-heating behavior. The present results, together with the changes in skin-cooling behavior during CSD reported previously, suggest the involvement of the frontal cortex in the central control of thermoregulation.