Seventy-five normal (control) children were compared to 15 hyperactive children on a Continuous Performance Test over an eight-week period. The control children were observed to have a relatively constant number of correct responses, chair movements, and reaction times throughout the testing period. However, when the hyperactive children were differentiated according to their scores on the Conner's Abbreviated Parent Questionnaire, those children scoring one standard deviation above the normative mean were later revealed to have more errors of commission and omission, chair movements, and a longer reaction time than did the normal control children.

Attention Deficit Disorder with Hyperactivity↗

PubMedDate not supplied

Objectively measured hyperactivity--II. Caffeine and amphetamine effects.

Errors of commission and omission, chair movements, and reaction times were assessed in fifteen previously diagnosed hyperactive children on a Continuous Performance Test after four drug regimens: amphetamine at doses of 1.6 and 5.0 mg twice a day, as well as 300 mg caffeine administered alone and with 1.6 mg amphetamine twice a day, produced significant reductions in errors of commission and increased reaction times in those children scoring 24 or more on the Conner's Abbreviated Parent Questionnaire. In addition, subjective symptoms on this questionnaire were significantly reduced by all drug treatments. The high (600 mg) daily dose of caffeine was observed to significantly control hyperactive symptoms, however, it also produced a number of side effects as well.

Attention Deficit Disorder with Hyperactivity↗

PubMedDate not supplied

Olfactory bulbectomy disrupts the expression of cocaine-induced conditioned place preference.

The role of the olfactory sense in the expression of cocaine-induced conditioned place preference (CPP) was examined in adult male rats (n = 35) of the N/Nih strain. Consistent with the scientific literature, rats were observed to significantly (p < 0.05) increase (double) the seconds spent in their least-preferred chamber following cocaine-chamber pairings. Subsequently, groups of rats underwent one of three treatments: 1) olfactory bulbectomy (BULBX), 2) sham surgery (SHAM), or 3) sham surgery plus intranasal zinc sulfate perfusion (ZnSO4). Zinc sulfate was used to produce a temporary loss of olfaction. In a separate behavioral measure of olfactory acuity, both BULBX and ZnSO4-treated rats performed at an equally deficient level, in contrast to SHAM-treated rats that were not rendered anosmic. A second conditioned place preference test revealed that the ZnSO4-perfused and SHAM groups did not differ from their original postcocaine preference measurements. In contrast, the BULBX group spent significantly fewer seconds in the cocaine-paired chamber. After a 14-day interval, a third preference test revealed that SHAM and ZnSO4-treated rats displayed an equivalent preference for the cocaine-paired chamber (at 2.7 times above baseline). Interestingly, the seconds spent in the cocaine-paired chamber by BULBX rats did not differ from their baseline (e.g., precocaine exposure). These results suggest that bulbectomy disrupts the expression of cocaine-induced place preference. Interpretations of data from BULBX rats involving the production of an anhedonic condition and the relevance of olfactory bulbectomy as an animal model of anhedonic depression are discussed.

Animals↗

PubMedDate not supplied

Cocaethylene produces discriminative stimulus properties in the rat: effect of cocaine and ethanol coadministration.

Experimentally naive Sprague-Dawley male rats were trained to discriminate the interoceptive stimulus cues produced by either 10.0 mg/kg cocaine or 10.0 mg/kg cocaethylene from their saline vehicles. Although it required more sessions to train the cocaethylene rats, once they were trained to criterion performance the ED50 value for cocaethylene (2.89 mg/kg) was very similar to that of cocaine (3.04 mg/kg). Coadministration of a 300-mg/kg dose of ethanol that produced saline-like responding in cocaethylene-trained rats with 2.5 mg/kg cocaine allowed for 88.9% of first lever selections being made on the cocaethylene-appropriate lever. Time-course evidence using coadministered (1.25-mg/kg) cocaine and (300-mg/kg) ethanol indicated that the formation of cocaethylene was highest, as indicated by discriminative performance, at 15 min and progressively decreased as the postinjection interval was increased to 30, 60, and 120 min. The results are discussed in light of rapid formation of cocaethylene from cotreatment with ethanol and cocaine in the mouse, rat, and human subject. The suggestion is made as to the prevalent, and growing, use of this drug combination in the human population of cocaine abusers.

Animals↗

PubMedDate not supplied

Serotonergic mediation of cocaine seizures in mice.

We used genetically heterogeneous HS mice to investigate the effects of drugs that alter brain concentrations of serotonin on cocaine-induced convulsions and lethality. The racemer of fenfluramine, which increases synaptic serotonin, was coadministered with a dose (60 mg/kg, intraperitoneally) of cocaine that does not produce status epilepticus or death. This drug combination significantly increased the occurrence and decreased the time of onset of status epilepticus, but did not affect lethality. Likewise, 2.5 mg/kg of the D-isomer, of fenfluramine increased the occurrence of status epilepticus. Neither isomer effected lethality. When 2.5 mg/kg cinanserin, a drug that antagonizes postsynaptic serotonergic receptors, was coadministered with a higher (95 mg/kg) dose of cocaine, the time of onset of status epilepticus was significantly increased, whereas lethality was reduced. The results are discussed in light of the action of cocaine upon serotonin neurons and the relationship between seizurogenic activity and cocaine-induced lethality.

Animals↗

PubMedDate not supplied

Role of dopamine D1 receptors in cocaine lethality.

One group of heterogeneously bred HS mice was assigned to test coadministration of the selective D1 antagonist SCH 23390 with a dose of cocaine (95 mg/kg) that was observed to produce 80% lethality, whereas a second group was tested by cotreatment with the newly developed full-efficacy D1 agonist dihydrexidine (DHX) and a dose of (60 mg/kg) cocaine previously shown to be nonlethal. The mice in the former group displayed decreased lethality going from 80% with coadministered vehicle to 15% after pretreatment with the highest dose (0.45 mg/kg) of SCH 23390. In the other group of mice there was no lethality seen when vehicle or 10 mg/kg DHX was coadministered with 60 mg/kg cocaine, but a dose-responsive increase in lethality with increasing DHX doses; the maximal lethality of 80% occurred when 25 mg/kg DHX was coadministered with cocaine. These results confirm the effects of D1 antagonism decreasing cocaine lethality as reported previously when rats were used, and extend the findings to D1 agonism; both observations evidence a role for the D1 receptor in the lethal effects, be they central, cardiopulmonary, or anesthetic, of cocaine.

Animals↗

PubMedDate not supplied

Cocaethylene produces conditioned place preference in rats.

The ability of cocaethylene to produce either a conditioned place preference or a conditioned place aversion was tested in rats. Twelve male rats were administered 10 mg/kg cocaethylene and confined to their nonpreferred side of the conditioned place preference apparatus as determined on a baseline test day. Subsequently, these rats spent a greater amount of time in that cocaethylene-paired nonpreferred side when later tested in a drug-free state. In contrast, rats conditioned with the same dose of cocaethylene and confined in their preferred side, as well as other rats treated with saline on both sides, did not show a significant shift in their preference or aversion. Results are discussed in light of the rewarding activity of cocaethylene, a compound formed in humans who concurrently use cocaine and ethanol.

Animals↗