Neonatal capsaicin exposure affects isolation-induced aggressive behavior and hypothalamic substance P levels of adult male mice (Mus musculus).
Subcutaneous administration of capsaicin (50 mg/kg) at Postnatal Days 2 and 5 exerted long-term effects on isolation-induced aggressive behavior of adult mice (Mus musculus) of the CD-1 strain. Isolated capsaicin-treated mice (scored during a 10-min session) showed the highest frequency and the longest duration of total attacks, attacks, rattling, and offensive upright posture when compared with nonisolated capsaicin-treated subjects and both isolated and nonisolated vehicle control animals. Hypothalamic Substance P (SP) was assessed by radioimmunoassay. Capsaicin treatment significantly lowered hypothalamic SP content in both isolated and nonisolated mice. Moreover, individual scores of isolated capsaicin-treated subjects showed a significant correlation between SP depletion and expression of offensive upright posture. Isolation per se was revealed to play an important role in depleting SP from the hypothalamus.
Bigi
S
S
Section of Behavioral Pathophysiology, Istituto Superiore di Sanità, Rome, Italy.
De Acetis
L
L
De Simone
R
R
Aloe
L
L
Alleva
E
E
D000374:Aggression / Q000187:drug effects*; D000378:Agonistic Behavior / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn; D002211:Capsaicin / Q000494:pharmacology*; D007031:Hypothalamus / Q000187:drug effects*; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D009619:Nociceptors / Q000187:drug effects; D017288:Pain Threshold / Q000187:drug effects; D012934:Social Isolation; D013373:Substance P / Q000378:metabolism*; D013697:Thermosensing / Q000187:drug effects
D013373:Substance P; D002211:Capsaicin