Influence of Pre-Exposure to Morphine on Cannabinoid-Induced Impairment of Spatial Memory in Male Rats.

Influence of pre-exposure to morphine on cannabinoid-induced impairment of spatial memory in male rats.

Behav Brain Res. 2013 Aug 1;
Farahmandfar M, Kadivar M, Naghdi N, Choopani S, Zarrindast MR

In the present study, we investigated the effects of pre-treatment with morphine on impairment of spatial memory acquisition induced by intra dorsal hippocampus (intra-CA1) administration of the non-selective cannabinoid CB1/CB2 receptor agonist, WIN55,212-2 in adult male rats. 2-day version of Morris water maze task has been used for the assessment of spatial memory. On the training day, rats were trained by a single training session of eight trials and 24h later a probe trial test consist of 60 s free swim period without a platform and the visible test was administered. Rats received pre-treatment subcutaneous (s.c.) injections of morphine, once daily for three days followed by five days drug-free treatment before training trials. The results indicated that bilateral pre-training intra-CA1 infusions of WIN55,212-2 (0.25 and 0.5?g/rat) impaired acquisition of spatial memory on the training and test day. The amnesic effect of WIN55, 212-2 (0.5?g/rat) was prevented in rats previously injected with morphine (20mg/kg/day×3 days, S.C.). Improvement in spatial memory acquisition in morphine-pretreated rats was inhibited by once daily administration of naloxone (1 and 2mg/kg, s.c.) 15min prior to injection of morphine for three days. The results suggest that sub-chronic morphine treatment may produced sensitization to cannabinoids, which in turn reversed the impairment of spatial memory acquisition induced by WIN55,212-2 and mu- opioid receptors may play an important role in this effect. HubMed – addiction

“Sleepless Nights and Sore Operation Site”: Patients’ Experiences of Nursing Pain Management After Surgery in Jordan.

Pain Manag Nurs. 2013 Aug 1;
Shoqirat N

Internationally, it is agreed that pain management is a central component of nursing care. Although much has been written about pain prevalence among patients after surgery, research is scant on patients’ experiences of nursing pain management and factors involved. This study explores patients’ experiences of nursing pain management in Jordan and identifies contributing factors. A qualitative research design was used. Data were collected through focus group discussions (n = 4). A total of 31 patients were purposively selected. Two main themes emerged. The first theme was living in pain and comprised two categories: from sleep disturbances to the fear of addiction and from dependence to uncertainty. The second theme was about barriers that affect nursing pain management. Patients’ experiences of nursing pain management were not up to their expectations; their needs were largely ignored and were dealt with in a mechanistic way. Barriers precipitating this situation were referred to in this study as the three “nots,” including not being well-informed, not being believed, and not being privileged. The study concluded that patients’ experiences of nursing pain management are a complex world that goes beyond medically orientated care. Nurses, therefore, are urged to look beyond standardized assessment tools and use patients’ experiences and voices as valuable evidence contributing to more effective pain management. Unless this occurs in their daily encounters with patients, another decade will pass with little change in the practice of pain management. HubMed – addiction

Expression of behavioral sensitization to ethanol is increased by energy drink administration.

Pharmacol Biochem Behav. 2013 Aug 1;
Ferreira SE, Abrahao KP, Souza-Formigoni ML

Alcohol abuse and dependence are important medical, social and economical problems, affecting millions of people. A relatively recent habit among young people is mixing alcohol with energy drinks (ED), in spite of the risks involved may be higher than those associated with alcohol consumption alone. The mixture of alcohol and energy drinks, both with stimulant properties, may alter the perception of intoxication and lead individuals to believe they are less drunk and can drink more or for longer periods of time. In animals, the repeated administration of ethanol can lead to a progressive increase of the locomotor stimulant effect, known as behavioral sensitization, a drug-dependent behavioral plasticity associated with vulnerability to addiction. As well as for addiction, there are clear individual differences in the level of sensitization to ethanol among species and even among individuals from the same strain. The present study assessed how ED affects the expression of ethanol sensitization. Female mice chronically treated with ethanol (2.4g/kg) were classified as low-sensitized or high-sensitized. Two days later, different groups of mice were submitted to saline+water, ethanol+water or ethanol+ED systemic challenges. As expected, only the high-sensitized group expressed clear sensitization after ethanol administration. However, the administration of ethanol+ED triggered the sensitization expression in the low-sensitized group. These data indicate the combined use of ED and ethanol can potentiate the stimulant and, consequently, the reward effects of ethanol in previously treated mice. If a similar process occurs in human beings, the use of ED can increase the risk of developing alcohol abuse or dependence. HubMed – addiction

Modeling Complexity of EMA Data: Time-Varying Lagged Effects of Negative Affect on Smoking Urges for Subgroups of Nicotine Addiction.

Nicotine Tob Res. 2013 Aug 3;
Shiyko M, Naab P, Shiffman S, Li R

Ecological momentary assessments (EMA) are increasingly used in studies of smoking behavior. Through EMA, examination of lagged relationships is particularly useful for establishing a temporal order of events and for identifying types and timing of risk factors. The time-varying effect model (TVEM) handles EMA data challenges and addresses unique questions about the time-varying effects.Generalized TVEM was applied to EMA data from a smoking cessation study to investigate a “time-varying lagged” effect of negative affect on high smoking urges. Participants included 224 smokers with a smoking history of 23.1 years (SD = 9.8) smoking 27.3 cigarettes per day (SD = 10.7), which provided 11,394 EMAs following a quit attempt and prior to a smoking lapse.The effect of negative affect was found to vary as a function of a time lag, with stronger immediate effects: estimated odds ratio (OR) of 2.7 for the lower nicotine-dependence group (time to first morning cigarette > 5min, 57.6%) and OR of 2.4 for the higher nicotine-dependence group (? 5min). The magnitude of the effect persisted up to 7hr while decreasing over time.This analysis confirmed the importance of negative affect as a precursor of smoking urges while showing that the magnitude of the effect varies over time. An assumption of a constant lagged effect may bias estimates of the relationships and fail to provide a comprehensive outlook of the relational dynamics. HubMed – addiction