Repeated Cocaine Exposure Increases Fast-Spiking Interneuron Excitability in the Rat Medial Prefrontal Cortex.

Repeated Cocaine Exposure Increases Fast-Spiking Interneuron Excitability in the Rat Medial Prefrontal Cortex.

J Neurophysiol. 2013 Mar 13;
Campanac E, Hoffman DA

The medial prefrontal cortex plays a key role in cocaine addiction. However, how chronic cocaine exposure affects cortical networks remains unclear. Most studies have focused on layer 5 pyramidal neurons (the circuit output) while the response of local GABAergic interneurons to cocaine remains poorly understood. Here, we recorded from fast-spiking interneurons (FS-INs) after repeated cocaine exposure and found altered membrane excitability. After cocaine withdrawal, FS-INs showed increased number of spikes evoked by positive current injection, increased input resistance, and decreased hyperpolarization-activated current. We also observed a reduction in miniature excitatory postsynaptic currents, whereas miniature inhibitory postsynaptic current activity was unaffected. We show that, in animals with cocaine history, dopamine receptor D2 activation is less effective in increasing FS-INs intrinsic excitability. Interestingly, these alterations are only observed a week or more after the last cocaine exposure. This suggests that the dampening of D2R mediated response can be a compensatory mechanism to rein down the excitability of FS-INs. HubMed – addiction

Alcoholism between Fiction and Reality.

Front Neurol Neurosci. 2013; 31: 169-77
Carota A, Calabrese P

Alcoholism has always been emphasized in literature, narratives, and theater as its prevalence and related disability are very high, is found throughout the world, and affects women and men of all ages and social classes. There is a tragic or romantic fascination in the deep sense of personal failure that drinking is able to relieve and in the uncontrollable inability to stop drinking. These aspects have been portrayed well by fictional alcoholics in movies and novels. It has become evident that biological traits together with a complex series of psychosocial factors (e.g. negative life events, depression, anxiety, and other psychiatric or personality disorders), which are also well represented in novels and movies, can lead to alcohol addiction. Behavioral (euphoria, disinhibiting behaviors, aggressiveness) and neurological changes (confusion, bradypsychism, slurred speech, ataxia, blackouts) related to alcohol intoxication are also well portrayed by fictional characters. Delirium tremens, epilepsy, alcohol dementia, and Wernicke-Korsakoff disease, however, find less representation in literature and on the stage and screen. The treatment of alcoholic dependence is very difficult (as often reported by fictional and real stories), but should never be considered hopeless. It should be initiated at any stage of the disease. The support offered by Alcoholics Anonymous has always had great appeal for the public. Fictional works can portray alcohol addiction superbly and show some dark sides of human nature (negative emotions and autodestructive thoughts and behaviors), and, at the same time, the severity and pervasiveness of mental illnesses. The psychiatric and psychosocial aspects of alcohol addiction in movies and novels could be an inspiring source for new psychological studies and rehabilitation programs. HubMed – addiction

Inflammatory and immunomodulatory mechanisms in the carotid body.

Respir Physiol Neurobiol. 2013 Feb 26;
Porzionato A, Macchi V, De Caro R, Di Giulio C

Evidence is available about the role of inflammatory/immunological factors in the physiology and plasticity of the carotid body, with potential clinical implications in obstructive sleep apnea syndrome and sudden infant death syndrome. In humans, lymphomonocytic aggregations (chronic carotid glomitis) have been reported in aging and opiate addiction. Glomus cells produce prostaglandin E2 and the cytokines interleukin 1?, interleukin 6 and TNF-?, with corresponding receptors. These factors modulate glomus cell excitability, catecholamine release and/or chemoreceptor discharge. The above cytokines are up-regulated in chronic sustained or intermittent hypoxia, and prevention of these changes, with ibuprofen or dexamethasone, may modulate hypoxia-induced changes in carotid body chemosensitivity. The main transcription factors considered to be involved are NF-kB and HIFs. Circulating immunogens (lipopolysaccharide) and cytokines may also affect peripheral arterial chemoreception, with the carotid body exerting an immunosensing function. HubMed – addiction

Patient Attitudes and Beliefs Regarding Pain Medication after Cardiac Surgery: Barriers to Adequate Pain Management.

Pain Manag Nurs. 2013 Feb 26;
Cogan J, Ouimette MF, Vargas-Schaffer G, Yegin Z, Deschamps A, Denault A

Several studies have outlined the impact of patient’s beliefs on their level of pain relief after surgery and have underlined that misconceptions are barriers to effective pain relief. The aim of this survey was to evaluate the beliefs of the patients to help create a specifically adapted pain education program. After ethics approval, all patients scheduled to undergo cardiac surgery of any kind were approached and asked to complete a voluntary, non-nominative questionnaire that included the Barriers Questionnaire and the Screening Tool for Addiction Risk (STAR) Questionnaire. All completed questionnaires were collected from the charts every evening or the morning before surgery. Of 564 patients scheduled for surgery, 379 patients (67.5%) returned questionnaires. The average age was 60.3 years, and 66.0% were male. Results of the Barriers Questionnaire showed that 31% of patients were in strong agreement that “it is easy to become addicted to pain medication,” 20% agreed that “good patients do not speak of their pain,” and 36% believe that “pain medication should be saved in case pain worsens.” Little or no gains have been made in decreasing misconceptions related to the treatment of pain. This study underlines the considerable need for and absolute necessity to provide pain education to patients undergoing cardiac surgery. HubMed – addiction