Elevated novelty seeking and peculiar d-amphetamine sensitization in periadolescent mice compared with adult mice.
Novelty seeking as well as amphetamine sensitization were studied in adult (postnatal day "PND" > 60) and periadolescent (PND 3343) mice treated with saline or amphetamine (2 or 10 mg/kg once per day) for 3 days in a familiar environment. After a 48-hr wash-out period, mice were challenged with either saline or amphetamine (2 mg/kg) in the same environment. When given a choice, animals showed a preference for a novel environment, an effect more marked in periadolescents. Acute amphetamine strongly increased novelty seeking in adults, whereas it had an opposite effect in periadolescents. Adult mice in the chronic amphetamine 2 group showed a conditioned preference for the drug-paired compartment, whereas an aversion characterized adult mice in the amphetamine 10 group. Periadolescents in the latter group exhibited a greater sensitization of the locomotor response, but did not show the compulsive licking typical of adults. This appears to be a useful model to study psychobiological risk factors involved in vulnerability to addiction during human adolescence.
Adriani
W
W
Behavioral Pathophysiology Section, Istituto Superiore di Sanità, Rome, Italy.
Chiarotti
F
F
Laviola
G
G
D000375:Aging / Q000187:drug effects* / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003345:Corticosterone / Q000097:blood; D003913:Dextroamphetamine / Q000494:pharmacology*; D004361:Drug Tolerance; D005106:Exploratory Behavior / Q000187:drug effects* / Q000502:physiology; D006120:Grooming / Q000187:drug effects; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D015999:Multivariate Analysis; D012095:Repression-Sensitization; D012107:Research Design
D000697:Central Nervous System Stimulants; D003913:Dextroamphetamine; D003345:Corticosterone