Intracranial Self-Administration Procedures for the Assessment of Drug Reinforcement

Author(s):  
Michael A. Bozarth
Author(s):  
Rianne R. Campbell ◽  
Siwei Chen ◽  
Joy H. Beardwood ◽  
Alberto J. López ◽  
Lilyana V. Pham ◽  
...  

AbstractDuring the initial stages of drug use, cocaine-induced neuroadaptations within the ventral tegmental area (VTA) are critical for drug-associated cue learning and drug reinforcement processes. These neuroadaptations occur, in part, from alterations to the transcriptome. Although cocaine-induced transcriptional mechanisms within the VTA have been examined, various regimens and paradigms have been employed to examine candidate target genes. In order to identify key genes and biological processes regulating cocaine-induced processes, we employed genome-wide RNA-sequencing to analyze transcriptional profiles within the VTA from male mice that underwent one of four commonly used paradigms: acute home cage injections of cocaine, chronic home cage injections of cocaine, cocaine-conditioning, or intravenous-self administration of cocaine. We found that cocaine alters distinct sets of VTA genes within each exposure paradigm. Using behavioral measures from cocaine self-administering mice, we also found several genes whose expression patterns corelate with cocaine intake. In addition to overall gene expression levels, we identified several predicted upstream regulators of cocaine-induced transcription shared across all paradigms. Although distinct gene sets were altered across cocaine exposure paradigms, we found, from Gene Ontology (GO) term analysis, that biological processes important for energy regulation and synaptic plasticity were affected across all cocaine paradigms. Coexpression analysis also identified gene networks that are altered by cocaine. These data indicate that cocaine alters networks enriched with glial cell markers of the VTA that are involved in gene regulation and synaptic processes. Our analyses demonstrate that transcriptional changes within the VTA depend on the route, dose and context of cocaine exposure, and highlight several biological processes affected by cocaine. Overall, these findings provide a unique resource of gene expression data for future studies examining novel cocaine gene targets that regulate drug-associated behaviors.


2015 ◽  
Vol 13 (2) ◽  
pp. 20-26
Author(s):  
Andrei Andreevich Lebedev ◽  
Eugeny Grigorievich Shumilov ◽  
Eugeny Rudolfovich Bychkov ◽  
Vitaly Ivanovich Morozov ◽  
Petr Dmitriyevich Shabanov

The orexin family of hypothalamic neuropeptides has been implicated in reinforcement mechanisms relevant to both food and drug reward. Previous behavioral studies with antagonists at the orexin A-selective receptor OX(1), have demonstrated its involvement in behavioral sensitization, conditioned place-preference, self-administration and reinstatement of drugs abuse. There are dense concentrations of hypocretin receptors, in brain regions implicated in drug reinforcement processes, such as the nucleus accumbens, ventral tegmental area and bed nucleus of the stria terminalis Adult male Wistar rats were implanted the stimulating electrodes to the lateral hypothalamus. Simultaneously, the microcanules were implanted into the BNST to inject the OX(1) receptor antagonist. Rats were trained to perform intracranial self-stimulation. The effects of the OX(1)-selective antagonist SB-408124 on brain stimulation-reward (BSR) were measured. SB-408124 injected into the BNST (1µg/1 µl in volume for each injection.) alone had no effect on self-stimulation of lateral hypothalamus. Amphetamine (1 mg/kg i.p.) potentiated BSR, measured as lowering of BSR threshold and enhancing of BSR frequency. Amphetamine-induced stimulatory effects on intracranial self-stimulation was blocked by injections of SB-408124 into BNST. These data demonstrate that OX(1) play an important role in regulating the reinforcing and reward-enhancing properties of amphetamine and suggest that orexin transmission is likely essential for establishing and maintaining the amphetamine habit in human addicts. However, the observations that OX1 antagonism reduce brain reward and block stress- and cue-induced reinstatement of drug-seeking suggests that this class of compounds may be useful additions to stress-reduction and other behavioral therapies in the treatment of substance abuse disorders.


1977 ◽  
Vol 55 (4) ◽  
pp. 778-790 ◽  
Author(s):  
Roger Stretch

Intravenous cocaine self-injection behaviour was studied using a new discrete-trials procedure in monkeys. Daily sessions consisted of two sets of 40 discrete trials, separated by a 5-min time out (TO) period; the intertrial interval during each segment of the session was equal to 50 s. In the first experiment, cocaine self-injection behaviour (15 μg/kg per injection) was suppressed in a dose-dependent manner by morphine pretreatment (1–5.6 mg/kg, im). When cocaine self-injection responding was suppressed by morphine pretreatment (3 or 5.6 mg/kg, im), the morphine antagonist, naloxone (0.01–1.0 mg/kg, im), reinstated drug-taking behaviour; the effect depended upon the dose of the antagonist and upon the amount of morphine given to suppress cocaine self-administration behaviour. When monkeys were pretreated with chlorpromazine (0.03–5.6 mg/kg, im) before a cocaine self-injection session, small doses marginally increased responding and larger doses exerted a suppressive effect. These effects were observed when cocaine was available at a unit dose of 15 μg/kg per injection. When the unit dose of cocaine was increased to 300 μg/kg per injection, small doses of chlorpromazine (0.03–1 mg/kg, im) exerted no clearly detectable effects, though responding for drug injections was profoundly suppressed when sessions were preceded by chlorpromazine pretreatment at doses of 3 and 5.6 mg/kg, im. In this experiment, drug intake per session was greater when a large injection dose (300 μg/kg per injection) was available for self-administration than when a small dose (15 μg/kg per injection) could be self-injected; the frequency of drug self-injection was reduced, however, when the larger unit dose of cocaine replaced the smaller one. When considered in relation to the results of other experiments, it is evident that control of cocaine self-injection responding by a discrete-trials procedure results in schedule-dependent behaviours that differ in relative sensitivity to drug pretreatments from cocaine-reinforced responding controlled by fixed-ratio schedules of drug reinforcement.


2021 ◽  
Author(s):  
Caitlin A. Murphy ◽  
Yu-Hsuan Chang ◽  
Rajesh Pareta ◽  
Jun-Nan Li ◽  
Tom Earnest ◽  
...  

AbstractPrescription opioid use is an initiating factor driving the current opioid epidemic. There are several challenges with modeling prescription opioid addiction. First, prescription opioids such as oxycodone are orally self-administered and have different pharmacokinetics and dynamics than morphine or fentanyl. This oral route of administration determines the pharmacokinetic profile, which is critical for establishing reliable drug-reinforcement associations in animals. Second, intravenous (i.v.) opioid self-administration is typically performed with intermittent drug self-administration sessions in a separate environment from the home cage. This does not recapitulate prescription opioid use, which is characterized by continuous drug access in the patients’ homes. To model features of prescription opioid use and the transition to abuse, we developed an oxycodone self-administration paradigm that is administered in the home cage. Mice voluntarily self-administer oxycodone in this paradigm without any taste modification such as sweeteners, and exhibit preference for oxycodone, escalation of intake, physical signs of dependence, reinstatement of seeking after withdrawal, and a subset of animals demonstrate drug taking that is resistant to negative consequences. This model is therefore translationally relevant and can be useful for studying the neurobiological substrates specifically relevant to prescription opioid abuse.


Methodology ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Joachim Gerich ◽  
Roland Lehner

Although ego-centered network data provide information that is limited in various ways as compared with full network data, an ego-centered design can be used without the need for a priori and researcher-defined network borders. Moreover, ego-centered network data can be obtained with traditional survey methods. However, due to the dynamic structure of the questionnaires involved, a great effort is required on the part of either respondents (with self-administration) or interviewers (with face-to-face interviews). As an alternative, we will show the advantages of using CASI (computer-assisted self-administered interview) methods for the collection of ego-centered network data as applied in a study on the role of social networks in substance use among college students.


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