A Novel Model of Chronic Sleep Restriction Reveals an Increase in the Perceived Incentive Reward Value of Cocaine in High Drug-Taking Rats.

A Novel Model of Chronic Sleep Restriction Reveals an Increase in the Perceived Incentive Reward Value of Cocaine in High Drug-Taking Rats.

Pharmacol Biochem Behav. 2013 Apr 18;
Puhl MD, Boisvert M, Guan Z, Fang J, Grigson PS

Substance abuse and sleep deprivation are major problems in our society. Clinical studies suggest that measures of poor sleep quality effectively predict relapse to substance abuse. Previously, our laboratory has shown that acute sleep deprivation increases the rate and efficiency (i.e., the goal-directed nature of responding) of cocaine self-administration using a progressive ratio (PR) schedule of reinforcement. However, the problem of sleep deprivation in our nation is largely one of chronicity. Therefore, the current study used a rodent model of chronic sleep restriction more akin to that experienced by humans (approximately 40% reduction in baseline sleep over the course of 8days) to assess the impact of chronic sleep deprivation on cocaine-seeking and cocaine-taking behaviors in rats early during acquisition of self-administration. While low drug-taking rats were unaffected by chronic sleep restriction, high drug-takers in the chronic sleep restriction (CSR) group exhibited enhanced fixed ratio (FR) responding by the fourth day of FR training and significantly higher PR breakpoints than their non-sleep restriction (NSR) counterparts. This study is the first to directly assess the impact of chronic sleep deprivation on drug self-administration. These results show that chronic sleep deprivation early during acquisition of self-administration has a significant effect on the perceived incentive reward value of cocaine in high drug-takers, as indicated by both increased FR responding and an increased willingness to work for drug. Thus, it is important to be mindful of such factors in clinical settings designed for treatment of addiction and relapse prevention. HubMed – addiction



Brain Res. 2013 Apr 18;
Roedding AS, Tong S, Au-Yeung W, Li PP, Warsh JJ

Recent findings implicate the calcium-permeable transient receptor potential (TRP) melastatin subtype 2 (TRPM2) and canonical subtype 3 (TRPC3) channels in the pathogenesis of bipolar disorder (BD). As both channels are involved in calcium and oxidative stress signalling, thought to be disrupted in BD, we sought to determine the effects of elevated oxidative stress on their expression and function. Primary rat cortical neurons and astrocytes were treated with oxidative stressors for 1 (acute) and 4 days (chronic). Expression of TRPC3 and TRPM2 were determined by immunoblotting and real-time PCR. Channel functionality was assessed using a TRPC3 activator, 1-oleoyl-2-acetyl-sn-glycerol (OAG), and live cell, ratiometric fluorometry with the calcium sensitive dye, Fura-2. Neurons treated with rotenone (15-30nM) for 4 days but not 24 hours showed significant dose-dependent decreases in TRPC3 mRNA (31%, p<0.001) and protein levels (60%, p<0.001). Similar dose-dependent attenuation of TRPC3-mediated calcium fluxes was demonstrated upon chronic rotenone exposure relative to vehicle controls. In contrast, TRPM2 mRNA but not protein levels increased (47%, p=0.017) after acute and chronic rotenone treatment. Chronic exposure of neurons to paraquat (1-2µM), an alternate oxidative stressor, similarly decreased TRPC3 expression (mRNA: 41%; protein: 61%). Unlike neurons, rotenone treatment incurred no changes in astrocyte TRPC3 levels. These findings demonstrate that TRPC3 and TRPM2 channel expression and/or function is sensitive to the redox status of rat primary neurons and that these changes are time dependent. This provides a critical mechanistic link between altered oxidative stress markers, dysfunction of these TRP channels and calcium dyshomeostasis in BD. HubMed – addiction


Adverse event assessment, analysis, and reporting in recent published analgesic clinical trials: ACTTION systematic review and recommendations.

Pain. 2013 Mar 14;
Smith SM, Wang AT, Katz NP, McDermott MP, Burke LB, Coplan P, Gilron I, Hertz SH, Lin AH, Rappaport BA, Rowbotham MC, Sampaio C, Sweeney M, Turk DC, Dworkin RH

The development of valid and informative treatment risk-benefit profiles requires consistent and thorough information about adverse event (AE) assessment and participants’ AEs during randomized controlled trials (RCTs). Despite a 2004 extension of the Consolidated Standards of Reporting Trials (CONSORT) statement recommending the specific AE information that investigators should report, there is little evidence that analgesic RCTs adequately adhere to these recommendations. This systematic review builds on prior recommendations by describing a comprehensive checklist for AE reporting developed to capture clinically important AE information. Using this checklist, we coded AE assessment methods and reporting in all 80 double-blind RCTs of noninvasive pharmacologic treatments published in the European Journal of Pain, Journal of Pain, and PAIN® from 2006 to 2011. Across all trials, reports of AEs were frequently incomplete, inconsistent across trials, and, in some cases, missing. For example, >40% of trials failed to report any information on serious adverse events. Trials of participants with acute or chronic pain conditions and industry-sponsored trials typically provided more and better-quality AE data than trials involving pain-free volunteers or trials that were not industry sponsored. The results of this review suggest that improved AE reporting is needed in analgesic RCTs. We developed an ACTTION (Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks) AE reporting checklist that is intended to assist investigators in thoroughly and consistently capturing and reporting these critically important data in publications. HubMed – addiction


Cytisine modulates chronic voluntary ethanol consumption and ethanol-induced striatal up-regulation of ?FosB in mice.

Alcohol. 2013 Apr 17;
Sajja RK, Rahman S

Chronic administration of ethanol induces persistent accumulation of ?FosB, an important transcription factor, in the midbrain dopamine system. This process underlies the progression to addiction. Previously, we have shown that cytisine, a neuronal nicotinic acetylcholine receptor (nAChR) partial agonist, reduces various ethanol-drinking behaviors and ethanol-induced striatal dopamine function. However, the effects of cytisine on chronic ethanol drinking and ethanol-induced up-regulation of striatal ?FosB are not known. Therefore, we examined the effects of cytisine on chronic voluntary ethanol consumption and associated striatal ?FosB up-regulation in C57BL/6J mice using behavioral and biochemical methods. Following the chronic voluntary consumption of 15% (v/v) ethanol under a 24-h two-bottle choice intermittent access (IA; 3 sessions/week) or continuous access (CA; 24 h/d and 7 d/week) paradigm, mice received repeated intraperitoneal injections of saline or cytisine (0.5 or 3.0 mg/kg). Ethanol and water intake were monitored for 24 h post-treatment. Pretreatment with cytisine (0.5 or 1.5 mg/kg) significantly reduced ethanol consumption and preference in both paradigms at 2 h and 24 h post-treatment. The ?FosB levels in the ventral and dorsal striatum were determined by Western blotting 18-24 h after the last point of ethanol access. In addition, cytisine (0.5 mg/kg) significantly attenuated up-regulation of ?FosB in the ventral and dorsal striatum following chronic ethanol consumption in IA and CA paradigms. The results indicate that cytisine modulates chronic voluntary ethanol consumption and reduces ethanol-induced up-regulation of striatal ?FosB. Further, the data suggest a critical role of nAChRs in chronic ethanol-induced neurochemical adaptations associated with ethanol addiction. HubMed – addiction