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R J Briscoe

Publications and source records attributed to R J Briscoe.

27 records · Page 2Linked to original sources
PubMed1995

Cross-generalization between a cocaine cue and two antihistamines.

Rats were trained to discriminate between 10 mg/kg cocaine and saline injections under a fixed ratio 10 schedule of food-motivated lever press responding. Once stimulus control was achieved, reinforced test sessions were conducted to assess the degree of generalization of a wide range of cocaine doses and the cross-generalization between the cocaine training stimulus and two over-the-counter antihistaminic drugs, diphenhydramine and doxylamine, when administered with saline or in drug combinations. Cocaine produced a dose-dependent generalization to the 10 mg/kg training stimulus. Cocaine also produced mild rate-increasing effects at low test doses and response rate suppression at higher doses. Both diphenhydramine and doxylamine produced a partial generalization to the 10 mg/kg cocaine training stimulus. Drug mixtures produced complete cross-generalization with the training cue.

Animals↗
PubMed1994

Cocaine-induced conditioned place approach in rats: the role of dose and route of administration.

The hedonic valence of the interoceptive stimuli associated with a wide range of cocaine doses administered by either SC or intraperitoneal injections was assessed in rats. Ninety-six male Sprague-Dawley rats were randomly assigned to different dose- and route-of-administration dependent groups (n = 8/group) and conditioned in a place learning task. During half of the conditioning trials, rats received either SC or intraperitoneal injections of saline or an individual dose of cocaine from 0.32 to 32 mg/kg (10 groups, 0.5 log common log unit increments), and were immediately placed in the initially nonpreferred compartment of a straight alley-way place-conditioning chamber. Prior to the other conditioning trials, rats received equivalent volumes of saline injections via the same routes of administration and were immediately placed in the initially preferred compartment. Two additional control groups received saline injections on both sides. Each rat received eight conditioning trials (four on each side). Significant conditioned place approach was produced by both SC- and IP-injected cocaine. However, the IP route of cocaine administration required a dose of 10 mg/kg cocaine to elicit a conditioned place approach, whereas a 0.32 mg/kg SC cocaine injection produced a CPP. Saline injections alone did not change the initial preference scores, and conditioned place aversions were not produced by any cocaine dose. The results of the present study demonstrate the relative safety of SC cocaine administration in the rat and a behavioral potency difference between these two routes of administration relative to the hedonic valence of the associated subjective states.

Animals↗
PubMed1994

Technical report: the subcutaneous administration of cocaine in the rat.

Eight male Sprague-Dawley rats were treated with 32 mg/kg cocaine, twice daily, for 2 weeks using a SC route of administration. Using a cocaine stock solution of 1.2-1.6 mg of cocaine hydrochloride per ml of sterile saline, we demonstrate, for the first time, the relative safety of subcutaneously administered cocaine in the rat. There was absolutely no evidence for focal dermal necrosis, in any rat, after the 2-week chronic period.

Animals↗
PubMed1994

Influence of thiamine on the behavioral sensitivity to ethanol.

Changes in sensitivity to ethanol's rate-decreasing effects on operant performance were examined in control rats and cohorts that received diet-induced or diet+pyrithiamine-induced thiamine deficiency. Seven groups of male Sprague-Dawley rats (12 rats/group) were trained in a 5-cycle lever-press operant task under a fixed-ratio 30 schedule of food reinforcement. Once trained to maintain consistent operant performance across all 5 cycles, each rat was tested with various doses of ethanol injected at the beginning of each time-out cycle. Each group of rats demonstrated equivalent saline baseline operant performance and ED50 for ethanol's rate-suppressing effects. Training sessions were suspended and rats received either a short- (9 days) or long-term (5-week) exposure to regular rat chow diet or thiamine-deficient diet, and received either saline or pyrithiamine injections in a 2 x 2 design. Three additional control groups were maintained on a regular rat chow diet and received supplemental injections of either thiamine+pyrithiamine injections, thiamine+saline injections, or saline+pyrithiamine injections. The controlled diet phase continued until the development of overt signs of thiamine deficiency, at which time thiamine supplements were administered for 4 days. In phase 3, all rats were retrained in the operant task and a second ethanol dose-effect function was generated. A history of thiamine deficiency and recovery failed to shift the behavioral dose-effect functions significantly for ethanol and their associated blood alcohol curves. Most interestingly, significant behavioral sensitization to ethanol's rate suppressant effects was demonstrated in the two control groups of rats receiving regular rat chow diet in combination with supplemental injections of thiamine and either saline or pyrithiamine.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholic Intoxication↗
PubMedDate not supplied

Aversive attributes of ethanol can be attenuated by dyadic social interaction in the rat.

Forty-eight male Sprague-Dawley rats were conditioned with either water or 4 g/kg ethanol in a standard drug place-learning task. In addition to the drug treatment, the opportunity for social interaction with either a sober or intoxicated conspecific was varied across groups (N = 8 rats/group). Ethanol produced a robust conditioned place aversion. The opportunity for dyadic social interaction with either a sober or intoxicated cohort attenuated the aversive attributes of ethanol. However, the initial preference scores did not significantly shift in water-conditioned rats in isolation or given access to either a sober or intoxicated cohort. These data are similar to clinical reports and suggest that social factors can influence the aversive affective properties of ethanol.

Affect↗
PubMedDate not supplied

Cross-generalization of an EtOH "hangover" cue to endogenously and exogenously induced stimuli.

Twenty male Sprague-Dawley rats were trained in a two-choice food-reinforced drug discrimination task (10 min sessions) using the state-dependent interoceptive stimulus attributes of ethanol's (EtOH) delayed or rebound effects (EDE) versus "normal" basal homeostasis. Cross-generalization tests were conducted with 0.18 mg/kg naloxone injected after three days of three injections per day of either SAL or 10 mg/kg morphine. Naloxone failed to generalize to the EDE-state after chronic saline; however, the precipitated morphine withdrawal state produced complete generalization to the EDE training cue. Daily tests were conducted after 8 h photoperiod phase-shifts. An 8 h phase-advance, equivalent to a west-to-east intercontinental night-time flight in humans, produced a biphasic, graded, increase in EDE-appropriate responding, which peaked on the second day after the phase-advance and recovered by the fourth day. The 8 h phase-delays failed to engender significant EDE-appropriate responding. These data provide evidence for the subjective similarity between EtOH hangover, opiate withdrawal states, and the physiological disruption induced by circadian phase-advances.

Animals↗
PubMedDate not supplied

Cumulative vs. acute dose-response procedures produce differential BAC and behavioral functions for ethanol.

The discriminative stimulus attributes of ethanol (ETOH) were characterized in rats trained to discriminate between 1.25 g/kg ETOH and saline. The ETOH generalization functions were assessed using both acute and cumulative dosing procedures. The cumulative procedures differed in the individual incremented doses used to generate the functions. Acute dosing procedures produced discriminative functions that were significantly different from cumulative dose-response curves (DRCs). Similar cumulative DRC's were generated within each cumulative dosing procedure, whereas significant differences were produced between the two dosing incremented procedures. When blood alcohol concentrations (BACs) were quantified, a cumulative testing procedure produced significantly lower BACs than acute testing procedures at every dose above the initial or starting dose. Interestingly, response rate functions did not differ within or between cumulative and acute procedures. These data may suggest that differential ETOH dosing procedures may differentially influence the behavioral choice and BAC functions in rats, and cautions against the use of cumulative procedures to assess shifts in DRCs during chronic treatments without a concomitant assessment of BACs.

Animals↗
PubMedDate not supplied

The paradoxical hedonic valence of acute ethanol withdrawal (hangover) states in rats: place and taste conditioning.

The hedonic valence of EtOH's delayed effects, usually referred to as "hangover," was assessed 18 h after a 4 g/kg injection using both place and taste learning tasks. In the place conditioning task two CS-,CS+ intervals were used (48 h and 144 h); within each treatment interval, experimentally induced "hangover" was paired with the initially nonpreferred conditioning compartment for half of the experimental group (N = 10 rats) and with the initially preferred conditioning compartment for the half (N = 10 rats). Saline injections were paired with placement in the alternate conditioning compartment. A third group (N = 10 rats) was conditioned with milliliter equivalent volumes of saline on both sides. A conditioned place preference was conditioned with the hangover state-induced interoceptive stimuli. Attempts were made to taste condition 24 rats with the interoceptive stimulus attributes of hangover. Experimentally induced hangover was associated with an adipsogenic state, defined as a significant decline in voluntary intake of both saccharin and water, which prevented taste conditioning.

Animals↗