A study of neurodevelopmental findings in early adolescent delinquents.

Subtle deficits or delays in the development of the central nervous system in young children are associated with problems affecting learning, behavior, and social adjustment. Less is known about the impact of such neurodevelopmental dysfunction in adolescents. This study assesses the possible association between neurodevelopmental delays and juvenile delinquency.

Tolerance to the disruptive effects of arecoline on schedule-controlled behavior.

The roles of dispositional, physiological, and behavioral factors in the development of tolerance to the effects of arecoline on operant behavior were assessed. In Experiment I, rats were trained to press a lever on a variable-interval 15-s schedule for milk reinforcement. Dose-effect relationships were assessed prior to and during chronic arecoline (1.

Evaluation of a multidimensional assessment procedure for preschool children.

The Pediatric Examination of Educational Readiness was administered to 386 preschool children to determine whether the predictive value of this instrument could be enhanced by the inclusion of systematic measures of processing efficiency, selective attention, behavioral adaptation, and neuromaturation. Findings on these dimensions, as well as the traditional developmental attainment measure, were consistent with McCarthy cognitive scores. Concerns regarding developmental attainment, processing efficiency, and selective attention were more common in children later found to have weak kindergarten mastery skills.

Investigations on the CNS sites of action of the discriminative stimulus effects of arecoline and nicotine.

The role of the dorsal hippocampus (DH) and mesencephalic reticular formation (MRF) in mediating the discriminative stimulus (DS) effects of nicotine and arecoline was assessed. In rats trained to discriminate nicotine (1.14 mg/kg) from saline, peripherally administered nicotine generalized to injection of nicotine, but not arecoline, directly into the DH and MRF.

Central sites and mechanisms of action of nicotine.

Research conducted in this laboratory over the last ten years has been directed towards determining possible CNS sites and mechanisms by which nicotine is producing its psychopharmacological effects. To accomplish these goals, a drug discrimination paradigm was utilized in which rats were trained to detect nicotine using a two-lever operant procedure. In this situation nicotine acted as a discriminative stimulus (DS) to correct lever responding.

Discriminative stimulus properties of arecoline: a new approach for studying central muscarinic receptors.

Rats were trained to discriminate arecoline (1.74 mg/kg) from saline in a milk-reinforced (variable interval 12s) two-lever operant paradigm. The discriminative stimulus (DS) effects of arecoline were antagonized by atropine sulfate, but not by atropine methylnitrate or mecamylamine.

Developmental output failure: a study of low productivity in school-aged children.

Children with low academic productivity in late elementary and junior high school present a vexing problem to parents and schools. A subgroup of these youngsters may have underlying subtle handicaps that result in reduced productivity and chronic underachievement. Such children may be clinically characterized as exhibiting "developmental output failure.

Discriminative stimulus properties of the optical isomers of nicotine.

Rats were trained to discriminate 200 or 400 microgram/kg (-)nicotine from saline in a two-bar operant paradigm. Dose-response relationships for optically pure (-)- and (+)nicotine as well as antagonistic effects were examined in both groups of rats. The natural isomer (-)nicotine was approximately nine-times more potent than (+)nicotine.

Comparison of phencyclidine and three analogues on fixed-interval performance in rhesus monkeys.

The effects of four arylcyclohexylamines on operant performance in rhesus monkeys were compared. Four rhesus monkeys were trained to lever press on a multiple fixed-interval 5 min time out 1 min schedule of food presentation during daily 1 1/2 hour sessions. Dose-response curves and median effective doses were determined for phencyclidine, N-ethyl-1-phenylcyclohexylamine, 1-(1-(2-thienyl) cyclohexyl) piperidine and ketamine.

Abstract reasoning in a specific group of perceptually impaired children: namely, the learning-disabled.

The present study was designed to investigate whether learning-disabled children differ from normal achievers in terms of logical thought and wheter they exhibit décalages intheir acquisition of Piagetian concepts. The Ss comprised 35 learning-disabled boys attending full-time remedial schools and 35 matched normal achievers. The group mean was 9 years 1 month and the mean IQ was 109.

1-alpha-acetylmethadol (LAAM), methadone and morphine abstinence in dependent rats: EEG and behavioral correlates.

Adult female Sprague-Dawley rats were prepared with chronic intravenous cannulas and cortical and muscle electrodes for recording electroencephalograms and electromyograms, respectively. They were made physically dependent on morphine by automatic intravenous injections and then trained to lever press in order to self-administer morphine on a FR-20 schedule of reinforcement. Upon stabilization of morphine self-administration, one group continued to self-administer morphine, while two other groups were switched to methadone or 1-alpha-acetylmethadol (LAAM) self-administration for an additional five to ten days.

Vesicular pemphigoid.

Seven patients had a chronic eruption of small vesicles that was initially considered to be atypical dermatitis herpetiformis. Histopathologic studies disclosed a subepidermal bulla that was compatible with either bullous pemphigoid or dermatitis herpetiformis. Immunofluorescence studies demonstrated deposition of IgG or C3, Or both, at the basement-membrane zone (BMZ) in six of seven patients.

Surgical correction of intertriginous soft corns.

A new surgical technique for the excision of intertriginous soft corns with advancement of the floor of toe webs is presented.

REM sleep distributions in post-addict rats relapsing to morphine self-administration: effects of naloxone subcutaneous pellets.

Female Sprague-Dawley rats were prepared with chronic cortical and temporalis muscle electrodes and i.v. cannulas.

Effects of naloxone subcutaneous pellets on relapse to morphine self-administration in post-addict rats.

Female Sprague-Dawley rats were prepared with chronic cortical and muscle electrodes and i.v. cannulae.