The Experts below are selected from a list of 3390 Experts worldwide ranked by ideXlab platform
Angus C Nairn - One of the best experts on this subject based on the ideXlab platform.
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contrasting features of erk1 2 activity and synapsin i phosphorylation at the erk1 2 dependent site in the rat brain in status epilepticus induced by kainic acid in vivo
Brain Research, 2015Co-Authors: Yoko Yamagata, Angus C NairnAbstract:Extracellular signal-regulated kinase 1/2 (ERK1/2) plays diverse roles in the central nervous system. Activation of ERK1/2 has been observed in various types of neuronal excitation, including seizure activity in vivo and in vitro. However, studies examining ERK1/2 activity and its substrate phosphorylation in parallel are scarce especially in seizure models. We have been studying the phosphorylation state of the presynaptic protein, synapsin I at ERK1/2-dependent and -independent sites in various types of seizure models and showed that ERK1/2-dependent phosphorylation of synapsin I was indeed under control of ERK1/2 activity in vivo. To further expand our study, here we examined the effects of prolonged seizure activity on ERK1/2 activity and synapsin I phosphorylation by using status epilepticus induced by kainic acid (KA-SE) in rats in vivo. In KA-SE, robust ERK1/2 activation was observed in the hippocampus, a representative Limbic Structure, with lesser activation in the parietal cortex, a representative non-Limbic Structure. In contrast, the phosphorylation level of synapsin I at ERK1/2-dependent phospho-site 4/5 was profoundly decreased, the extent of which was much larger in the hippocampus than in the parietal cortex. In addition, phosphorylation at other ERK1/2-independent phospho-sites in synapsin I also showed an even larger decrease. All these changes disappeared after recovery from KA-SE. These results indicate that the phosphorylation state of synapsin I is dynamically regulated by the balance between kinase and phosphatase activities. The contrasting features of robust ERK1/2 activation yet synapsin I dephosphorylation may be indicative of an irreversible pathological outcome of the epileptic state in vivo.
H Beckmann - One of the best experts on this subject based on the ideXlab platform.
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confirmation of reduced temporal Limbic Structure volume on magnetic resonance imaging in male patients with schizophrenia
Psychiatry Research-neuroimaging, 1996Co-Authors: T Becker, Karl Elmer, Frank Schneider, Matthias Schneider, Wolfgang Grodd, Matthias Bartels, Stephan Heckers, H BeckmannAbstract:A structural deficit in the temporal lobes has been implicated in the pathogenesis of schizophrenia. A prospective magnetic resonance imaging (MRI) study was carried out in 20 young male patients with schizophrenia and 20 age-matched healthy male volunteers. Volumetric measurements were performed in all slices with temporal lobe cross-sections from the temporal pole to the tip of the Sylvian fissure. Volumetric assessment included the temporal lobe as a whole, hippocampal formation and amygdala complex, temporal horn and cella media of the lateral ventricle, the third ventricle, and hemispheric volume in all slices that showed temporoLimbic Structures. Brain structural deficit in the patients was most conspicuous in the posterior portion of the hippocampal formation. Significant effects of diagnosis were also found for the total temporal lobe and the third ventricle. Multiple regression analysis revealed posterior hippocampal volume to be significantly determined by diagnosis, but not by age or by temporal lobe or hemispheric volume. Significant correlations of morphologic and clinical parameters were restricted to negative correlations of temporal lobe volume with the global rating and sum score of the Scale for the Assessment of Negative Symptoms. The study confirms subtle temporoLimbic deficit reported in previous MRI studies in patients with schizophrenia.
Yukiori Goto - One of the best experts on this subject based on the ideXlab platform.
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chronic stress modulation of prefrontal cortical nmda receptor expression disrupts Limbic Structure prefrontal cortex interaction
European Journal of Neuroscience, 2011Co-Authors: Younga Lee, Yukiori GotoAbstract:Chronic stress causes various detrimental effects including cognitive and affective dysfunctions. Given the recent findings emphasizing the importance of information processing between the prefrontal cortex (PFC) and Limbic Structures on cognitive and affective functions, impairments of these functions caused by chronic stress may be associated with stress-induced adaptive and maladaptive responses in Limbic Structure-PFC interaction. In this study we have shown that chronic stress disrupts Limbic Structure-PFC interaction by modulating N-methyl-D-aspartate (NMDA) receptor expression in the PFC. We found that chronic stress decreased expression of NR1, NR2A and NR2B subunits of NMDA receptors in the PFC but not in the motor cortex. However, the reduction in NR2B subunits of NMDA receptors was larger in the dorsal part than the ventral part of PFC. In agreement with this observation, administration of the NMDA antagonist that was more selective for NMDA receptors containing NR2B subunits induced alterations of synchronous local field potentials between the PFC and Limbic Structures, synaptic plasticity induction in the Limbic Structure-PFC pathway, and spike firing of PFC neurons that were similar to those observed in the dorsal PFC of rats exposed to chronic stress. In contrast, administration of the NMDA antagonist that was not subunit-selective resulted in electrophysiological alterations resembling to those observed in the ventral PFC of rats exposed to chronic stress. These results suggest that chronic stress disrupts NMDA receptor-dependent Limbic Structure-PFC information processing.
Linda J. Porrino - One of the best experts on this subject based on the ideXlab platform.
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The role of the olfactory tubercle in the effects of cocaine, morphine and brain-stimulation reward
Brain research, 1991Co-Authors: Conan Kornetsky, David Huston-lyons, Linda J. PorrinoAbstract:Using the quantitative 2-[14C]deoxyglucose autoradiographic method, local rates of glucose utilization were measured in rats after the administration of morphine or cocaine in the presence or absence of rewarding brain stimulation to the medial forebrain bundle. In animals that did not receive brain stimulation, cocaine significantly increased glucose utilization in the olfactory tubercle, medial prefrontal cortex and substantia nigra pars reticulata, whereas morphine significantly increased glucose metabolism in the olfactory tubercle only. Stimulation itself increased metabolic rates in a number of sites, such as the olfactory tubercle, nucleus accumbens, medial prefrontal cortex, ventral tegmental area and others. However, in self-stimulating animals both morphine and cocaine caused further increases in activity in the olfactory tubercle. Since the olfactory tubercle was the only Structure to cause a significant increase in metabolic rate following each treatment, the results implicate this Limbic Structure in the rewarding effects of morphine, cocaine and brain-stimulation reward.
T Becker - One of the best experts on this subject based on the ideXlab platform.
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confirmation of reduced temporal Limbic Structure volume on magnetic resonance imaging in male patients with schizophrenia
Psychiatry Research-neuroimaging, 1996Co-Authors: T Becker, Karl Elmer, Frank Schneider, Matthias Schneider, Wolfgang Grodd, Matthias Bartels, Stephan Heckers, H BeckmannAbstract:A structural deficit in the temporal lobes has been implicated in the pathogenesis of schizophrenia. A prospective magnetic resonance imaging (MRI) study was carried out in 20 young male patients with schizophrenia and 20 age-matched healthy male volunteers. Volumetric measurements were performed in all slices with temporal lobe cross-sections from the temporal pole to the tip of the Sylvian fissure. Volumetric assessment included the temporal lobe as a whole, hippocampal formation and amygdala complex, temporal horn and cella media of the lateral ventricle, the third ventricle, and hemispheric volume in all slices that showed temporoLimbic Structures. Brain structural deficit in the patients was most conspicuous in the posterior portion of the hippocampal formation. Significant effects of diagnosis were also found for the total temporal lobe and the third ventricle. Multiple regression analysis revealed posterior hippocampal volume to be significantly determined by diagnosis, but not by age or by temporal lobe or hemispheric volume. Significant correlations of morphologic and clinical parameters were restricted to negative correlations of temporal lobe volume with the global rating and sum score of the Scale for the Assessment of Negative Symptoms. The study confirms subtle temporoLimbic deficit reported in previous MRI studies in patients with schizophrenia.