Addiction Rehab: Modulation of Ventral Tegmental Area Dopamine Receptors Inhibit Nicotine-Induced Anxiogenic-Like Behavior in the Central Amygdala.
Modulation of ventral tegmental area dopamine receptors inhibit nicotine-induced anxiogenic-like behavior in the central amygdala.
Filed under: Addiction Rehab
Prog Neuropsychopharmacol Biol Psychiatry. 2012 Nov 21;
Zarrindast MR, Eslahi N, Rezayof A, Rostami P, Zahmatkesh M
Nicotine, the major addictive substance in tobacco, increases the activity of the central amygdala (CeA). Amygdala is directly implicated in anxiety modulation and sends projections to the vicinity of midbrain dopamine neurons, including the ventral tegmental area (VTA) which is key area that controls nicotine dependence processes. In this study, the role of dopamine D(1) and D(2)/(3) receptors of the VTA on anxiogenic-like behavior induced with intra-CeA injection of nicotine has been investigated. Male Wistar rats with cannula aimed to the left CeA and the left VTA were submitted to the elevated plus-maze (EPM). The nicotine injection (1?g/rat) into the CeA decreased the percentage of open arm time and open arm entries, but not locomotor activity, indicating an anxiogenic-like response. Intra-VTA injection of a dopamine D1 receptor antagonist, SCH23390 (0.25?g/rat), and a dopamine D2/3 receptor antagonist, sulpiride (0.7?g/rat), inhibited the anxiogenic-like response caused by intra-CeA injection of nicotine. These results suggest that relationship between the VTA and the CeA may be involved in nicotine-induced anxiogenic-like behavior via dopamine D(1) and D(2)/(3) receptors. An understanding of these cellular processes will be crucial for the development of new intervention to combat nicotine effect.
HubMed – addiction
Psychoactive “bath salts”: Not so soothing.
Filed under: Addiction Rehab
Eur J Pharmacol. 2012 Nov 22;
Baumann MH, Partilla JS, Lehner KR
Recently there has been a dramatic rise in the abuse of so-called “bath salts” products that are purchased as legal alternatives to illicit drugs like cocaine and 3,4-methylenedioxymethamphetamine (MDMA). Baths salts contain one or more synthetic derivatives of the naturally-occurring stimulant cathinone. Low doses of bath salts produce euphoria and increase alertness, but high doses or chronic use can cause serious adverse effects such as hallucinations, delirium, hyperthermia and tachycardia. Owing to the risks posed by bath salts, the governments of many countries have made certain cathinones illegal, namely: 4-methylmethcathinone (mephedrone), 3,4-methylenedioxymethcathinone (methylone) and 3,4-methylenedioxypyrovalerone (MDPV). Similar to other psychomotor stimulants, synthetic cathinones target plasma membrane transporters for dopamine (i.e., DAT), norepinephrine (i.e., NET) and serotonin (i.e, SERT). Mephedrone and methylone act as non-selective transporter substrates, thereby stimulating non-exocytotic release of dopamine, norepinephrine and serotonin. By contrast, MDPV acts as a potent blocker at DAT and NET, with little effect at SERT. Administration of mephedrone or methylone to rats increases extracellular concentrations of dopamine and serotonin in the brain, analogous to the effects of MDMA. Not surprisingly, synthetic cathinones elicit locomotor activation in rodents. Stimulation of dopamine transmission by synthetic cathinones predicts a high potential for addiction and may underlie clinical adverse effects. As popular synthetic cathinones are rendered illegal, new replacement cathinones are appearing in the marketplace. More research on the pharmacology and toxicology of abused cathinones is needed to inform public health policy and develop strategies for treating medical consequence of bath salts abuse.
HubMed – addiction
STK38 is a critical upstream regulator of MYC’s oncogenic activity in human B-cell lymphoma.
Filed under: Addiction Rehab
Oncogene. 2012 Nov 26;
Bisikirska BC, Adam SJ, Alvarez MJ, Rajbhandari P, Cox R, Lefebvre C, Wang K, Rieckhof GE, Felsher DW, Califano A
The MYC protooncogene is associated with the pathogenesis of most human neoplasia. Conversely, its experimental inactivation elicits oncogene addiction. Besides constituting a formidable therapeutic target, MYC also has an essential function in normal physiology, thus creating the need for context-specific targeting strategies. The analysis of post-translational MYC activity modulation yields novel targets for MYC inactivation. Specifically, following regulatory network analysis in human B-cells, we identify a novel role of the STK38 kinase as a regulator of MYC activity and a candidate target for abrogating tumorigenesis in MYC-addicted lymphoma. We found that STK38 regulates MYC protein stability and turnover in a kinase activity-dependent manner. STK38 kinase inactivation abrogates apoptosis following B-cell receptor activation, whereas its silencing significantly decreases MYC levels and increases apoptosis. Moreover, STK38 knockdown suppresses growth of MYC-addicted tumors in vivo, thus providing a novel viable target for treating these malignancies.Oncogene advance online publication, 26 November 2012; doi:10.1038/onc.2012.543.
HubMed – addiction
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