Functional regulation of tactile sense by brain-derived neurotrophic factor in adult rats during acute inflammation

Nerve growth factor is present in skin in limiting amounts and is known to regulate the plasticity and the sensitivity of nociceptive neurons. Recentl y, knock-out mouse studies showed that neurotropkin-3 and brain-derived neu rotrophic factor are required for the postnatal survival and functional mat uration, respectively, of tactile sensory neurons. However, the roles of ne urotrophin-3 and brain-derived neurotrophic factor in adult sensory neurons have not been clarified. Here, we report an unexpected and marked acute lo ss of tactile sense in the rat hind paw after adjuvant-induced inflammation . This loss was shown to be closely correlated with decreases in the expres sion of brain-derived neurotrophic factor, and to a lesser extent of neurot rophin-3 in the inflamed skin. Administration of brain-derived neurotrophic factor, but not neurotrophin-3, after inflammation accelerated the recover y of tactile sense. These results suggested a role of brain-derived neurotrophic factor in the physiological regulation of tactile sense in adulthood. (C) 2000 IBRO. Publ ished by Elsevier Science Ltd.