Nucleus accumbens and dopamine-mediated turning behavior of the rat: role of accumbal non-dopaminergic receptors.
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Accumbal dopamine plays an important role in physiological responses and diseases such as schizophrenia, Parkinson's disease, and depression. Since the nucleus accumbens contains different neurotransmitters, it is important to know how they interact with dopaminergic function: this is because modifying accumbal dopamine has far-reaching consequences for the treatment of diseases in which accumbal dopamine is involved. This review provides a summary of these interactions, and our current knowledge about them are as follows: A) AMPA receptors are required for dopamine-dependent behavior and vice versa; NMDA receptors modulate the activity at the level of AMPA and/or dopamine D(1) receptors. B) GABA(A), but not GABA(B), receptors inhibit dopamine-dependent behavior. C) Nicotinic receptors are required for dopamine-dependent behavior, whereas muscarinic receptors inhibit dopamine-dependent behavior. D) alpha-Adrenoceptors inhibit dopamine-dependent behavior in contrast to beta-adrenoceptors, which potentiate this behavior. E) mu- and delta(2)-opioid receptors elicit behavior that requires an intact dopaminergic function and delta(2)-opioid receptors modulate dopamine-dependent behavior. F) Orexin 2 receptors play an important, modifying role in dopamine-dependent behavior. G) Somatostatin receptors potentiate dopamine-dependent behavior. It is suggested that modulation of the above-mentioned non-dopaminergic receptors provide new tools to control physiological functions as well as diseases mediated by accumbal dopamine. (+info)
A case of quackery and obsession for diastema resulting in avoidable endodontic therapy.
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BACKGROUND: Perception of midline diastema differs among individuals and cultures. To some, it is a feature of beauty, while to others it is aesthetically appalling. From a scientific point of view, midline diastema is a deviation from normal adult dentition. It is not uncommon among some African natives to find individuals demanding for artificially created midline diastema from dental practitioners. OBJECTIVE: To present a rare case of pulpal necrosis involving maxillary and mandibular central incisors as a result of poorly executed teeth modification in a bid to create upper and lower midline diastemata. RESULT: A 23-year old lady presented with history of spontaneous, sharp, persistent pain associated with palatal swelling and discharging sinus of two weeks duration in relation to maxillary central incisors (11, 21). The complaint was preceded by a history of recurrent pain in relation to 11, 21, 31 and 41 which started soon after obtaining artificially created maxillary and mandibular midline diastemata from a dental quack. Periapical x-ray revealed periapical radiolucency in relation to 21 and 41. Vitality test confirmed necrotic pulp in the lower central incisors. The affected teeth were scheduled for root canal therapy (RCT) and porcelain fused to metal crown. The RCT of 11 and 21 had been completed but further treatment stalled due to financial constraint. CONCLUSION: This is a case of obsession for midline diastema, poor dental health education, and illegal dental practice. (+info)
Association between the COMT gene and rumination in a Hungarian sample.
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INTRODUCTION: Rumination is a multidimensional trait which is a proven risk factor in the vulnerability to depression. The aim to identify the main risk genes for depression in addition to the gene-environment interactions pointed to the importance of intermediate phenotypes, like rumination, to improve our understanding of the biological mechanisms of depression. Catechol-O-Methyltransferase (COMT) gene is extensively investigated in depression with contradictory results but its association with rumination, as an intermediate phenotype in depression, has not been investigated yet. METHODS: In our study, four tagging SNPs in the COMT gene (rs933271, rs740603, rs4680, rs4646316) were genotyped in a nonclinical Hungarian sample (n=939). We investigated the association between the COMT gene and rumination scores measured by the Ruminative Response Scale using haplotype trend regression. RESULTS: We found a significant association between COMT haplotypes and rumination scores (p=0.013) but no significant association was apparent between the functional Val158Met polymorphism (rs4680) and rumination in any genetic model. DISCUSSION: Variations in the COMT gene exert complex effects on susceptibility to depression involving intermediate phenotypes, such as rumination and also impulsivity, as we previously demonstrated. Both rumination and impulsivity represent maladaptive cognitive styles that can lead to depressive state by influencing the response to negative life events and life stressors. In conclusion, our findings provide evidence that in addition to other genes, COMT also has a significant role in the development of depression, and demonstrate that analysing the complex phenotype associations of genes by haplotype tagging is a powerful method. (+info)
Disgust, mental contamination, and posttraumatic stress: unique relations following sexual versus non-sexual assault.
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