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Repeated administration of high doses of methamphetamine produced long-term decreases in dopamine (DA) levels and in the number of DA uptake sites in the rat striatum. These two effects were dose-related and did not appear to be due to the continued presence of drug in striatal tissue. Long-lasting depletions induced by methamphetamine were selective for(More)
Studies are described in which normal healthy volunteers were tested with a wide range of intravenous doses of cocaine of d-amphetamine. Physiological measurements included heart rate, electrocardiogram, blood pressure, respiration rate, and temperature. Behavioral measures included the use of the Profile of Mood States to assess drug-related mood changes,(More)
(+/-)-3,4-Methylenedioxyamphetamine (MDA), an amphetamine analog with hallucinogenic activity, produced selective long-lasting reductions in the level of serotonin, the number of serotonin uptake sites, and the concentration of 5-hydroxyindoleacetic acid in rat brain. Morphological studies suggested that these neurochemical deficits were due to serotonin(More)
The discriminative stimulus (DS) effects of smoked marijuana were studied by training marijuana smokers to discriminate between the effects of marijuana containing 2.7% delta 9-THC (M) and marijuana containing 0.0% delta 9-THC (P). In addition to measures of discrimination responding, subjective effects were assessed with standardized mood questionnaires.(More)
The effects of cocaine (4.0--32 mg/kg) on schedule-controlled behavior of rats were determined before and during a period of repeated administration of cocaine. In rats trained to lever press on a fixed ratio 40 schedule for food delivery, cocaine (8.0--32 mg/kg) initially decreased response rate in a dose-related manner. During the period of repeated(More)
Numerous recent studies indicate that when amphetamines are administered continuously or in high doses, they exert long-lasting toxic effects on dopamine (DA) neurons in the central nervous system (CNS). Specifically, it has been shown that amphetamines can decrease the content of brain DA, reduce the number of synaptosomal DA uptake sites and selectively(More)
Repeated high doses (25 and 100 mg/kg) of methylamphetamine produce long-term depletions of both dopamine (DA) and serotonin (5-HT) in the rat brain. In the DA system, depletions are most pronounced in the neostriatum and substantia nigra, with decreased levels in these two regions being significantly correlated. Within the 5-HT system, levels are most(More)
The relationships between drug dosage per injection and response rate, and drug dosage per injection and total daily drug intake were ascertained in Rhesus monkeys which self-administered cocaine, pipradrol, methylphenidate and phenmetrazine intravenously. The study demonstrated the monkeys would self-administer all of these compounds over a wide range of(More)
Methamphetamine and amphetamine were continuously administered to rats for 3 days by means of subcutaneously implanted osmotic minipumps. The total daily dose of each drug was approximately 4 mg/day. Dopamine, norepinephrine and serotonin determinations two weeks later indicated that both amphetamines produced a selective striatal dopamine depletion.(More)
BACKGROUND Chronic cocaine abuse remains a serious and costly public health problem. This study assessed the effectiveness of a voucher-based reinforcement contingency in producing sustained cocaine abstinence. METHODS A randomized controlled trial compared voucher-based reinforcement of cocaine abstinence to noncontingent voucher presentation. Patients(More)