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Specific Brain Areas (specific + brain_area)
Selected AbstractsCircuits and systems in stress.DEPRESSION AND ANXIETY, Issue 1 2002Abstract This paper follows the preclinical work on the effects of stress on neurobiological and neuroendocrine systems and provides a comprehensive working model for understanding the pathophysiology of posttraumatic stress disorder (PTSD). Studies of the neurobiology of PTSD in clinical populations are reviewed. Specific brain areas that play an important role in a variety of types of memory are also preferentially affected by stress, including hippocampus, amygdala, medial prefrontal cortex, and cingulate. This review indicates the involvement of these brain systems in the stress response, and in learning and memory. Affected systems in the neural circuitry of PTSD are reviewed (hypothalamic-pituitary-adrenal axis (HPA-axis), catecholaminergic and serotonergic systems, endogenous benzodiazepines, neuropeptides, hypothalamic-pituitary-thyroid axis (HPT-axis), and neuro-immunological alterations) as well as changes found with structural and functional neuroimaging methods. Converging evidence has emphasized the role of early-life trauma in the development of PTSD and other trauma-related disorders. Current and new targets for systems that play a role in the neural circuitry of PTSD are discussed. This material provides a basis for understanding the psychopathology of stress-related disorders, in particular PTSD. Depression and Anxiety 16:14,38, 2002. © 2002 Wiley-Liss, Inc. [source] Brain GABA editing by localized in vivo1H magnetic resonance spectroscopyNMR IN BIOMEDICINE, Issue 2 2004G. Bielicki Abstract Editing of GABA by 1H MRS in a specific brain area is a unique tool for in vivo non-invasive investigation of neurotransmission disorders. Selective GABA detection is achieved using sequences based on double quantum coherence (DQC). Our pulse sequence makes accurate measurements without artefacts due to spatial localization. The sequence was tested on a phantom solution. The effect of vigabatrin, a specific inhibitor of GABA transaminase, was measured in rat brain and GABA detection was performed in vivo in monkey brain using this procedure. Rats were spilt into two groups. In the control group, the rats had access to water and, in the other group (vigabatrin, VGB, rats), animals were allowed free access to drinking water containing vigabatrin. After 3 weeks of treatment, rats were anesthetized for in vivo NMR spectroscopy investigation. At the end of the experiment, brains were quickly removed, freeze-clamped and extracted with 4% perchloric acid. One part of the acid extract was used for GABA concentrations assessment by ion exchange chromatography with ninhydrin detection. The second was used for high-resolution NMR analysis. By chromatography measurements, the GABA concentration was 1.23±0.06,,mol/g for controls, while for vigabatrin-treated rats the GABA concentration was 4.89±1.60,,mol/g. The NMR in vivo results were closely correlated with the NMR ex vivo (r=0.99, p<0.01) and chromatography results (r=0.98, p<0.01). The correlation between ex vivo results and chromatography results was also high (r=0.99, p<0.001). This pulse sequence performed GABA editing from a 376,,l voxel located on the right basal ganglia area in a non-human primate brain. This in vivo GABA editing scheme can thus be proposed for accurate measurement of brain GABA concentrations. Copyright © 2004 John Wiley & Sons, Ltd. [source] Seasonal plasticity of brain aromatase mRNA expression in glia: Divergence across sex and vocal phenotypesDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2005Paul M. Forlano Abstract Although teleost fishes have the highest levels of brain aromatase (estrogen synthase) compared to other vertebrates, little is known of its regulation and function in specific brain areas. Previously, we characterized the distribution of aromatase in the brain of midshipman fish, a model system for identifying the neural and endocrine basis of vocal-acoustic communication and alternative male reproductive tactics. Here, we quantified seasonal changes in brain aromatase mRNA expression in the inter- and intrasexually dimorphic sonic motor nucleus (SMN) and in the preoptic area (POA) in males and females in relation to seasonal changes in circulating steroid hormone levels and reproductive behaviors. Aromatase mRNA expression was compared within each sex throughout non-reproductive, pre-nesting, and nesting periods as well as between sexes within each season. Intrasexual (male) differences were also compared within the nesting period. Females had higher mRNA levels in the pre-nesting period when their steroid levels peaked, while acoustically courting (type I) males had highest expression during the nesting period when their steroid levels peaked. Females had significantly higher levels of expression than type I males in all brain areas, but only during the pre-nesting period. During the nesting period, non-courting type II males had significantly higher levels of aromatase mRNA in the SMN but equivalent levels in the POA compared to type I males and females. These results demonstrate seasonal and sex differences in brain aromatase mRNA expression in a teleost fish and suggest a role for aromatase in the expression of vocal-acoustic and alternative male reproductive phenotypes. © 2005 Wiley Periodicals, Inc. J. Neurobiol, 2005 [source] Long-term Changes in Postnatal Susceptibility to Pilocarpine-induced Seizures in Rats Exposed to Gamma Radiation at Different Stages of Prenatal DevelopmentEPILEPSIA, Issue 10 2003Zuzanna Setkowicz Summary:,Purpose: To determine whether brains irradiated at different stages of prenatal development also have different postnatal susceptibility to seizures evoked by pilocarpine. Methods: Pregnant Wistar rats were exposed to a single 1.0-Gy dose of gamma rays on gestation days 13, 15, 17, or 19 (E13, E15, E17, and E19, respectively). On postnatal day 60, their offspring received i.p. pilocarpine injections to evoke status epilepticus. Behavior of the animals was observed continuously for 6 h after the injection, and motor manifestations of seizure activity were rated, and survival times recorded. After 7-day survival, the animals were killed, and their brains were weighed. Results: The average brain weight of animals exposed to irradiation at earlier prenatal stages (E13 or E15) was significantly lower than that after irradiation on E17 or E19. However, effects of the irradiation on the susceptibility to pilocarpine-induced seizures were quite opposite. The intensity of status epilepticus evoked in rats irradiated on E13 or E15 was significantly lower than that in nonirradiated controls or in those irradiated on E17 or E19. Moreover, after irradiation on E13 or E15, survival of the animals was significantly higher in relation not only to other irradiated groups but also to the controls. Conclusions: The results suggest than the extent of neuronal deficit, even if relatively greater, cannot always lead to higher susceptibility of the dysplastic brain to seizures. Functional consequences of the deficit, even if its magnitude is relatively smaller but involving specific brain areas, appear to be critical for the epileptogenesis. [source] Serotonin norepinephrine reuptake inhibitors (SNRIs) in anxiety disorders: a comprehensive review of their clinical efficacyHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 1 2010Bernardo Dell'Osso Abstract Anxiety disorders are common psychiatric conditions that typically require long-term treatment. This review summarizes current knowledge of the pharmacological treatment of anxiety disorders with serotonin norepinephrine reuptake inhibitors (SNRIs) with specific emphasis on the findings of recent randomized clinical trials and relevant neurobiological investigations. It is now well established that gabaergic, noradrenergic and serotonergic systems play a critical role in the pathophysiology of anxiety disorders, abnormalities in these systems being related to structural and functional alterations in specific brain areas such as the amygdala, prefrontal cortex, locus coeruleus and hippocampus, as repeatedly shown by neuroimaging studies. SNRIs selectively inhibit norepinephrine and serotonin reuptake and have shown to be efficacious and generally well tolerated treatments in patients with anxiety disorders, with some potential clinical advantages over selective serotonin reuptake inhibitors (SSRIs), which are considered by many to represent first-line pharmacological treatments in patients with anxiety disorders. Anxiety disorders are characterized by a typically chronic course, high rates of comorbidity and frequent partial response to standard treatments, and the increasing use of SNRIs reflects currently unmet clinical need, in terms of overall response, remission rates and treatment tolerability. Copyright © 2009 John Wiley & Sons, Ltd. [source] Unawareness in schizophrenia: Neuropsychological and neuroanatomical findingsPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 5 2006LORENZO PIA phd Abstract, The lack of insight in schizophrenia has so far been interpreted as a primary symptom of the illness, namely a defensive mechanism rather than a neurologically-based condition. However, recent findings have emphasized its relationship with damage to specific brain areas as well as the domain specificity in which it may occur. This supports a neuropsychological interpretation of the lack of insight in schizophrenia. The present article reviews the foregoing data, and takes into account the most relevant anatomo-clinical results. There is evidence that the lack of insight in schizophrenia may occur as a neurological disease per se following brain damage that seems related to frontal lobe areas. Additionally, it could either be related to all aspects of the disease or be domain-specific, occurring for one kind of symptom but not for others. These data indicate several analogies with the phenomenon called anosognosia for a neurological deficit. [source] Functional neural correlates of mindfulness meditations in comparison with psychotherapy, pharmacotherapy and placebo effect.ACTA NEUROPSYCHIATRICA, Issue 3 2010Is there a link? Chiesa A, Brambilla P, Serretti A. Functional neural correlates of mindfulness meditations in comparison with psychotherapy, pharmacotherapy and placebo effect. Is there a link? Objective: Mindfulness meditations (MM) are a group of meditation practices which are increasingly receiving attention. The aim of the present work is to review current findings about the neural correlates of MM and compare such findings with other specific and non-specific treatments. Methods: A literature search was undertaken using MEDLINE, ISI web of knowledge, the Cochrane database and references of retrieved articles. Studies which focused on the functional neural correlates of MM, psychotherapy, pharmacotherapy and placebo published up to August 2009 were screened in order to be considered for the inclusion. Results: Main findings suggest that long-term MM practice allows a more flexible emotional regulation by engaging frontal cortical structures to dampen automatic amygdala activation. A large overlap exists between cerebral areas activated during MM, psychotherapy, pharmacotherapy and those activated by placebo. However, while MM, psychotherapy and placebo seem to act through a top-down regulation, antidepressants seem to act through a bottom-up process. Conclusion: MM seem to target specific brain areas related to emotions and emotional regulation. Similar mechanisms have been observed also in other interventions, particularly psychotherapy. [source] | ||||||||||