Neuroscience and biobehavioral reviews
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Neurosci Biobehav Rev · Jul 2008
ReviewSpinal glial activation contributes to pathological pain states.
Chronic pain, a pathological state, affects millions of people worldwide. Despite decades of study on the neuronal processing of pain, mechanisms underlying the creation and maintenance of enhanced pain states after injury or inflammation remain far from clear. In the last decade, however, the discovery that glial activation amplifies pain has challenged classic neuronal views of "pain". ⋯ We overview the action of spinal glia (both microglia and astrocytes) in several persistent pain models, and provide new evidence that spinal glia activation contributes to the development and maintenance of arthritic pain facilitation. We also attempt to discuss some critical questions, such as how signals are conveyed from primary afferents to spinal glia following peripheral nerve injury and inflammation. What causes glia to become activated after peripheral/central injury/inflammation? And how the activated glia alter neuronal sensitivity and pain processing? Answers to these questions might open a new approach for treatment of pathological pain.
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Neurosci Biobehav Rev · Jan 2008
ReviewAnatomy and physiology of the basal ganglia: implications for DBS in psychiatry.
The basal ganglia have been a target for neuromodulation surgery since Russell Meyers' pioneering works in the late 1930s. Contemporary movement disorder surgery on the brain has evolved from empiric observations on movement behavior after neurological lesions. So too has the development of psychiatric surgical procedures followed the observation of lesions in the brain on cognitive and affective behavior. ⋯ DBS targeting this circuitry appears from initial evidence in obsessive-compulsive disorder (OCD) to be a promising option for patients with neuropsychiatric illness resistant to conventional therapies. Further exploring the anatomic interconnectivity of the physiologically relevant cortical and subcortical areas will inevitably lead to better applications of DBS for the treatment of OCD, major depression (MD) and potentially for other psychiatric disorders. Implementing such therapies optimally will require the creation of treatment centers with specialized expertise in the psychiatric, neurosurgical, and ethical issues that arise with these populations.
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Neurosci Biobehav Rev · Jan 2007
ReviewTransient patterns of cortical lamination during prenatal life: do they have implications for treatment?
Transient laminae containing circuitry elements (synapses, postsynaptic neurons and presynaptic axons) appear in the cerebral wall from the eighth postconceptional week (PCW) and disappear with the resolution of the subplate zone after the sixth postnatal month. The first endogeneous synaptic circuitry develops in two laminae, above and below the cortical plate. Mid- and late fetal period (15-23PCW) shows lamination pattern with a thick subplate zone containing GABAergic, glutamatergic and peptidergic neurons, synapses and thalamocortical afferents which are waiting and accumulating in the superficial subplate zone between 21 and 23PCW and these mark regional boundaries. ⋯ Corticocortical pathways continue to grow. In the neonatal period, there is a major reorganization of callosal projections and development of short corticocortical connections, dendritic spines and synapses. In conclusion, transient neuronal circuitry underlies transient functions during the fetal, perinatal and early postnatal life and determines developmental plasticity of the cerebral cortex and moderates effects of lesion of the developing brain.
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Animal models of human diseases should meet three sets of criteria: construct validity, face validity, and predictive validity. To date, several putative animal models of bipolar disorder have been reported. They are classified into various categories: pharmacological models, nutritional models, environmental models, and genetic models. ⋯ These mice showed altered diurnal activity rhythm and periodic activity change associated with the estrous cycle. These phenotypes were worsened by administration of a tricyclic antidepressant, but improved after lithium treatment. This mouse model of bipolar disorder potentially fulfills the three validity criteria, and therefore might be used for future drug development studies.
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Neurosci Biobehav Rev · Jan 2007
ReviewDifferent behaviors and different strains: potential new ways to model bipolar disorder.
The state of animal models for bipolar disorder (BPD) is deficient, creating a major problem in the research related to this devastating disorder and in our ability to translate molecular findings to the clinic. An ideal model, a "bipolar animal" is most likely unattainable as long as we do not fully understand the biological basis of the disorder, and no models are currently available to reflect the cycling nature of the disease. Yet, additional, better and more practical models need to be developed to support research efforts in the field. ⋯ A similar approach has been used previously to model other psychiatric disorders and can be utilized for BPD research. An example of this possible approach is shown with the Black Swiss mice strain that appears to have more manic-like behaviors compared to other strains. Both approaches will not culminate to an ideal, all encompassing model of BPD but may provide useful and relatively uncomplicated tools for research of the disorder.