Psychomotor stimulant effects of d-amphetamine, MDMA and PCP: aggressive and schedule-controlled behavior in mice.
The objective of the present experiments was to characterize psychomotor stimulant effects of d-amphetamine, methylenedioxymethamphetamine (MDMA) and phencyclidine (PCP) on conditioned performance and on aggressive behavior in mice. In a novel protocol with alternating periods of schedule-controlled responding and aggressive behavior toward an intruder it was possible to assess a range of species-specific agonistic acts, postures, and motor activities as well as response rates and patterns engendered by a multiple Fixed Interval (FI) and Fixed Ratio (FR) schedule within the same animal. Initially, it was confirmed that d-amphetamine and, less reliably, MDMA and PCP, increased FI, but not FR responding in mice. In the next experiment, mice confronted an intruder at the midpoint of the 1-h daily session; following the display of aggressive behavior, the rate of FI responding showed an amphetamine-like increase, whereas only a transient change occurred after non-aggressive encounters. Thirdly, using this new protocol, PCP, d-amphetamine and MDMA altered FI and FR responding in a way that was closely similar to the first experiment. Low PCP and d-amphetamine doses increased aggressive behavior erratically in certain individuals, but not reliably for the group. MDMA dose-dependently decreased aggressive behavior, and all drugs disrupted aggressive behavior at higher doses. The characteristic increases in walking and decreases in rearing after higher doses of PCP and d-amphetamine were greatly attenuated when the intruder was present.(ABSTRACT TRUNCATED AT 250 WORDS)
Miczek
K A
KA
Department of Psychology, Tufts University, Medford, MA 02155.
Haney
M
M
D000374:Aggression / Q000187:drug effects*; D000818:Animals; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D003913:Dextroamphetamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000494:pharmacology*; D010622:Phencyclidine / Q000494:pharmacology*; D012055:Reinforcement Schedule
D000697:Central Nervous System Stimulants; D010622:Phencyclidine; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D003913:Dextroamphetamine