Environmental Enrichment Effects on the Neurobehavioral Profile of Selective Outbred Trait Anxiety Rats.

Environmental enrichment effects on the neurobehavioral profile of selective outbred trait anxiety rats.

Behav Brain Res. 2013 May 29;
Ravenelle R, Byrnes EM, Byrnes JJ, McInnis C, Park JH, Donaldson ST

Environmental enrichment attenuates the response to psychostimulants and has been shown to reduce both anxiety and stress-related behaviors. Since stress is a major vulnerability factor for addiction, we investigated whether enrichment could reverse stress profiles in high anxious rats as well as reduce their amphetamine sensitivity. Using selectively-bred high and low anxiety males (filial 3) from enriched, social or isolated environments, we tested elevated plus maze exploration, novelty place preference and amphetamine (AMPH; 0.5mg/kg, IP)-induced hyperactivity. We measured plasma corticosterone (CORT) response after forced novel object exposure, phosphorylation of the tropomyosin-related kinase B receptor (pTrkB) in the hippocampus and striatum, and dopamine (D2) receptor mRNA levels in the striatum and nucleus accumbens. Results indicate that high anxiety animals reared in social or enriched environments spent more time on open arms of the EPM while low anxiety animals raised in enriched environments spent more time on open arms when compared to either isolated or social groups. There were no group differences or interactions found for novelty place preference. Enriched environments decreased the response to AMPH and stress-induced CORT regardless of trait but selectively decreased pTrkB and increased D2 mRNA levels in high anxiety animals. The results suggest that selectively-bred trait anxiety rats show state anxiety that is influenced by rearing environments, and D2 protein levels and BDNF/TrkB signaling may differentially contribute to integrating these effects. HubMed – addiction


[Cocaine addiction: Current data for the clinician.]

Presse Med. 2013 May 30;
Karila L, Zarmdini R, Petit A, Lafaye G, Lowenstein W, Reynaud M

Cocaine remains the second most commonly used illicit drug worldwide after cannabis. Observed levels of cocaine use among countries considerably vary. An increased cocaine use is recorded in the general European population. Cocaine addiction is a worldwide public health problem, which has somatic, psychiatric, socio-economic and judicial complications. It is a multifactorial disorder variable in its clinical manifestations and heritable. Compared to the general population, there is a high prevalence of somatic and psychiatric disorders among cocaine-dependent patients. There are predictable dose-related effects of pharmacological action of cocaine and effects which are uncommon, unrelated to dose and occur randomly in this population. The number of patients entering drug treatment for primary cocaine use has been increasing in Europe for several years. However, there is no specific pharmacotherapy with established efficacy for the treatment of cocaine addiction, nor is any medication approved by regulatory authorities for such treatment. Recent controlled clinical studies and laboratory studies have highlighted some very promising medications. The perfect therapeutic platform for abstinence initiation and relapse prevention of cocaine addiction is a combination of pharmacological treatments and behavioral treatments. Targeting somatic and psychiatric comorbidity is another way to use pharmacological treatments in addictions. HubMed – addiction


Non-prescribed use of substitution medication among German drug users-Prevalence, motives and availability.

Int J Drug Policy. 2013 May 30;
Schmidt CS, Schulte B, Wickert C, Thane K, Kuhn S, Verthein U, Reimer J

BACKGROUND: Beyond unquestioned merits of opioid substitution treatment (OST), non-prescribed use of substitution medication (NPU) and its availability on the black market still constitute critical issues. METHODS: This cross-sectional study was conducted in low-threshold drug services in 13 German cities. Clients were interviewed face-to-face, using a structured questionnaire on drug use patterns, prevalence and motives for NPU, and availability and prices of substitution medication on the black market. RESULTS: Our sample of 753 drug users (74.5% male) had a mean age of 36.4 years, 42.4% were currently in OST and 78.4% reported heroin use in the past 30 days. NPU prevalence for lifetime, past 30 days, and past 24h was 66.7%, 25.8%, and 9.3%. Access to substitution medication was considered ‘easy’. Injection of substitution medication was reported by 9.5% of our sample (i.e. 14.4% of injectors). Motives for NPU show large heterogeneity, with “lack of other drugs” and “insufficient OST dosage” as the reasons stated most frequently. CONCLUSIONS: NPU represents a relevant source of opiates among German drug users. While OST is associated with a reduction of illicit drug use and injection use, motives for NPU suggest that the treatment services do not sufficiently attract opioid-addicted persons. HubMed – addiction