title: Postnatal NGF administration causes adult hyperalgesia and overreactivity to social stimuli but does not reverse capsaicin induced hypoalgesia.
abstract: The present longitudinal analysis was aimed at assessing (i) the effects of developmental capsaicin (CAPS) administration on nociceptive responsivity and on the response of adult mice to social stimuli; (ii) the action of NGF on the ontogeny of the same nociceptive response and social stimuli; (iii) whether capsaicin treatment could be reversed by subsequent treatment with NGF. CD-1 mouse pups were treated with either capsaicin (50 mg/kg, s.c.) or vehicle on postnatal days (PNDs) 5 and 8. Every other day from PND 9 to PND 21 the same pups received a daily injection of NGF (0.75 mg/kg, s.c.). During both the prepuberal stage (PNDs 14, 21, and 28) and adulthood, mice were repeatedly tested in a hot-plate apparatus (52 +/- 0.1 degrees C for 1 min). At adulthood they also underwent an aggressive behaviour test. NGF-treated mice showed a shorter latency to hindlimb licking response in the hot plate compared to both controls and NGF-CAPS groups. CAPS-treated subjects showed a long-lasting hypoalgesia at both prepuberal and adult stages that was not modified by subsequent NGF treatment. Finally, NGF-treated mice were more aggressive than both controls and CAPS-NGF animals.
authors.affiliation: Section of Behavioural Pathophysiology, Istituto Superiore di Sanità, Rome, Italy. alleva@iss.it
authors.forename: E
authors.initials: E
authors.lastname: Alleva
authors.forename: L
authors.initials: L
authors.lastname: Aloe
authors.forename: F
authors.initials: F
authors.lastname: Cirulli
authors.forename: L
authors.initials: L
authors.lastname: De Acetis
authors.forename: C
authors.initials: C
authors.lastname: Padoa Schioppa
mesh_terms: D000374:Aggression / Q000187:drug effects*; D000818:Animals; D000831:Animals, Newborn; D002211:Capsaicin / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D005260:Female; D006358:Hot Temperature; D006930:Hyperalgesia / Q000139:chemically induced / Q000523:psychology*; D008297:Male; D051379:Mice; D009414:Nerve Growth Factors / Q000494:pharmacology*; D010147:Pain Measurement / Q000187:drug effects; D012919:Social Behavior
chemical_list: D009414:Nerve Growth Factors; D002211:Capsaicin