An implantable, focal brain cooling device suppresses nociceptive pain in rats.

Although the classic idea of controlling pain through focal brain cooling is intriguing, the mechanism of this effect still remains to be elucidated. A thermoelectronic cooling system was developed and chronically implanted on the ipsilateral sensorimotor cortex of rats. Significant suppression of nociceptive pain was observed in limbs contralateral to the cooling cortex in hot plate tests and thermal withdrawal tests (p<0.05), with a minimal influence on neurological functions. This study identified, for the first time, the specific site and temperatures for the suppression of nociceptive pain, thus showing the potential feasibility of thermal neuromodulation therapy for pain. Copyright 2009 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.