Diazepam self-administration and resistance to extinction.

Self-administration behavior was maintained by a unit dose of 0.03 mg/kg diazepam in 4 of 5 monkeys trained to respond on a lever by successive approximation using diazepam or saline. A dose-response function was determined using diazepam doses ranging between 0.

Reinforcing and subjective effects of several anorectics in normal human volunteers.

A discrete-trial choice procedure was used to examine the reinforcing and subjective effects of four anorectic drugs (mazindol, benzphetamine, phenylpropanolamine and phenmetrazine) in groups of normal healthy adults. For each experiment, subjects first sampled placebo and a dose of one of the drugs (mazindol: 0.5, 1.

The reinforcing properties of amphetamine in overweight subjects and subjects with depression.

The reinforcing properties of amphetamine were assessed in two groups of subjects for whom the drug was hypothesized to be a more effective reinforcer than for control subjects. Preference for amphetamine (5 and 10 mg) over placebo was evaluated in subjects who were concerned about being overweight (n = 13), in subjects with depression (n = 15), and in control subjects (n = 25). Subjective effects of the drugs were measured by self-report questionnaires.

Amphetamine-like effects of anorectics and related compounds in pigeons.

Four pigeons were trained to discriminate injections of d-amphetamine (AMPH; 2.0 mg/kg i.m.

Benzodiazepine self-administration in rhesus monkeys: estazolam, flurazepam and lorazepam.

The ability of three benzodiazepines to maintain self-administration behavior was studied in rhesus monkeys using a substitution procedure. Lever-press responding was maintained in six monkeys under a fixed-ratio schedule of IV pentobarbital delivery in daily sessions of 3 hr duration. Each of several doses of flurazepam, lorazepam and estazolam as well as saline and vehicle was periodically substituted for 4-13 consecutive sessions.

Individual differences in behavioral and subjective responses to alcohol.

The reinforcing properties and subjective effects of alcohol were assessed in 29 normal volunteers using a seven-session choice procedure. On the first four sessions, subjects sampled an alcohol (0.5 g/kg) and a placebo beverage twice each.

Discriminative stimulus properties of oxazepam in the pigeon.

Five pigeons were trained to discriminate IM injections of oxazepam (4.0 mg/kg) from vehicle with responding maintained under a fixed-ratio 30 schedule of food delivery. Under test conditions, responding increased in a dose-dependent manner in all pigeons after the administration of other benzodiazepines including diazepam (0.

The effects of food deprivation on the self-administration of psychoactive drugs.

Under conditions of food deprivation, relative to the equivalent satiation condition, increases in the self-administration of d-amphetamine in three out of three monkeys, of cocaine in two out of three monkeys, and of nicotine in one out of three monkeys, were observed. Furthermore, these increases were dose-dependent, i.e.

Anorectics: effects on food intake and self-administration in rhesus monkeys.

The effects of the anorectics benzphetamine, chlorphentermine, clortermine, mazindol, phendimetrazine, and phenmetrazine on food intake were compared to the effects of d-amphetamine in rhesus monkeys given daily access to food pellets. The ability of these compounds to maintain intravenous self-administration under a fixed-ratio 10 schedule was also determined in rhesus monkeys. All drugs reduced food intake in a dose-related manner.

The effects of ethanol on eye tracking in rhesus monkeys and humans.

The effects of ethanol on eye tracking function were compared in rhesus monkeys and humans using a similar experimental procedure. In Experiment 1, 3 rhesus monkeys were trained to visually track a projected image of a disk that oscillated sinusoidally along a horizontal plane on a screen. This training was accomplished using a procedure in which responses on a lever resulted in the delivery of water when the central area of the projected disk image was dimmed for a brief period.

Discriminative stimulus properties of (+/-)-3,4-methylenedioxymethamphetamine and (+/-)-3,4-methylenedioxyamphetamine in pigeons.

Pigeons trained to discriminate (+)-amphetamine (AMPH) from saline in a two-key food-maintained drug discrimination paradigm, were used to investigate the discriminative stimulus (DS) effects of two structural analogues of amphetamine, namely (+/-)-3,4-methylenedioxymethamphetamine (MDMA) and (+/-)-3,4-methylenedioxyamphetamine (MDA). After discrimination performance was stable (90% injection-appropriate responding), test sessions with various doses of AMPH were conducted and a dose-dependent relationship for AMPH-appropriate responding was obtained. Both MDMA (3.

The effects of (+/-)-methylenedioxymethamphetamine and (+/-)-methylenedioxyamphetamine in monkeys trained to discriminate (+)-amphetamine from saline.

Recently, attention has been focused on (+/-)-methylenedioxymethamphetamine (MDMA), a psychotomimetic agent chemically closely related to the psychomotor stimulant methamphetamine, and also to the hallucinogen mescaline. In the present experiment, the effects of MDMA and (+/-)-3,4-methylenedioxyamphetamine (MDA) were determined in rhesus monkeys that were trained to discriminate intravenously administered (+)-amphetamine (AMPH) from saline in a two-lever, food-maintained paradigm or to discriminate intragastrically administered AMPH from saline in a signalled electric shock avoidance paradigm. MDMA produced 100% drug-appropriate responding in all six monkeys, regardless of the procedure and route of administration while MDA substituted completely for AMPH in only two of three monkeys in each paradigm.

The discriminative stimulus and subjective effects of phenylpropanolamine, mazindol and d-amphetamine in humans.

The discriminative stimulus (DS) and subjective effects of two anorectic drugs, phenylpropanolamine (PPA) and mazindol (MAZ), were studied in a group of normal, healthy adults trained to discriminate between placebo and 10 mg d-amphetamine (AMP). Of 20 subjects who underwent discrimination training, 12 (discriminators) reliably learned the AMP-placebo discrimination. Each discriminator was tested with two doses of PPA (25 and 75 mg) and two doses of MAZ (0.

Behavioral and neurochemical evaluation of phenylpropanolamine.

(+/-)-Phenylpropanolamine (PPA), a widely available anorectic and decongestant, was evaluated in several behavioral paradigms in rhesus monkeys and for central nervous system neurotoxicity in rats. PPA (1-30 mg/kg intragastric) reduced food intake in rhesus monkeys but was not self-administered i.v.

Lack of preference for diazepam in anxious volunteers.

Using a choice procedure, these experiments tested whether diazepam is more highly preferred by anxious subjects than by normal control subjects. Subjects first sampled and then chose between two capsules containing diazepam (5 or 10 mg) and placebo, or amphetamine (5 mg) and placebo. The number of times each drug was chosen over placebo and the subjective effects of the drugs were measured.

Third ventricle choroid plexus function and its response to acute perturbations in plasma chemistry.

The homeostatic role of the third ventricle choroid plexus (3VCP) in the maintenance of CSF electrolytes was investigated by quantifying alterations in CP epithelial ion concentrations induced by chemical perturbations of plasma in adult Sprague-Dawley rats. Significant regional differences (third vs fourth (4VCP) and lateral ventricle CP (LVCP] were found in epithelial content of Na+ and K+, with respect to baseline levels as well as alterations caused by 5-60 min of systemic metabolic acidosis. 3VCP, which comprises ca.

The effects of Ro 15-1788 on anxiolytic self-administration in the rhesus monkey.

The ability of a benzodiazepine antagonist, Ro 15-1788, to modify the self-administration of anxiolytics was determined in rhesus monkeys. Lever-press responding was maintained in four monkeys under a fixed-ratio 10 schedule of drug delivery in daily sessions of 2 hr duration. Responding was maintained either by flurazepam, lorazepam or pentobarbital.

The discriminative stimulus properties of cocaine and d-amphetamine: the effects of three routes of administration.

Five rhesus monkeys were trained to discriminate intramuscular cocaine (0.25 mg/kg, 10 min presession) from saline. In subsequent tests, intramuscular cocaine (0.

Effects of dopaminergic agents on eye tracking before and after repeated methamphetamine.

The effects of methamphetamine (MA), apomorphine (AP) and haloperidol (HAL) on eye tracking function were tested in rhesus monkeys. Three rhesus monkeys were trained to track with their eyes a disk-shaped projected image that oscillated along a horizontal plane on a screen, using a training procedure in which responses on a lever were reinforced with water only when the center of the disk dimmed for a brief period. Eye movements were recorded by electrooculography (EOG).

Individual differences in the reinforcing and subjective effects of amphetamine and diazepam.

This study explored the relation between the reinforcing properties of different drugs and their subjective effects. Preference for a drug (amphetamine or diazepam) over placebo was measured in a choice procedure, and mood changes after drug administration were monitored by self-report questionnaires. Individual differences in behavioral drug preferences were then examined for their relationships to subjective drug responses as well as other subject variables.

The discriminative stimulus and subjective effects of d-amphetamine, phenmetrazine and fenfluramine in humans.

The discriminative stimulus (DS) and subjective effects of d-amphetamine (AMP), phenmetrazine (PMT) and fenfluramine (FFL) were studied in a group of normal healthy adults. Subjects (N = 27) were trained to discriminate between placebo and 10 mg AMP (PO). Fourteen of the subjects (discriminators) reliably learned the discrimination, whereas the other 13 did not.