Brain and nerve = Shinkei kenkyū no shinpo
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Review Case Reports
[Anti-nMDA receptor encephalitis--clinical manifestations and pathophysiology].
Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a new category of treatment-responsive encephalitis associated with "anti-NMDAR antibodies", which are antibodies to the NR1/NR2 heteromers of NMDAR. The antibodies are detected in the CSF/serum of young women with ovarian teratoma, who typically develop schizophrenia-like psychiatric symptoms, usually preceded by fever, headache, or viral infection-like illness. After reaching the peak of psychosis, most patients developed seizures followed by an unresponsive/catatonic state, decreased level of consciousness, central hypoventilation frequently requiring mechanical ventilation, orofacial-limb dyskinesias, and autonomic symptoms. ⋯ Although recovery occurs without the need for tumor removal, the severity and extended duration of symptoms support tumor removal. Combined therapy including tumor resection and immunotherapy is recommended. In this review, we also discuss the relationship between anti-NMDAR encephalitis and related disorders, including acute diffuse lymphocytic meningoencephalitis and acute juvenile female non-herpetic encephalitis (AJFNHE).
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The limbic system (comprising the amygdala and the anterior cingulate cortex) and the prefrontal cortex (the orbital and dorsolateral prefrontal cortices) have been implicated in emotional and behavioral control. Selective lesion studies in rodents suggest that the basolateral nucleus of the amygdala, which is a critical subnucleus within the amygdala, plays a critical role in appetitive instrumental behaviors. On the other hand, the central nucleus of the amygdala directly receives afferents from the lateral nucleus of the amygdala. ⋯ The dorsolateral prefrontal cortex is involved in predicting of the outcome of own action, and the evaluation of the outcome for guiding optimal behaviors is based on its close reciprocal connections with the limbic system. These 4 regions of the brain interact with each other and work complementarily. In the present review, the abovementioned functions of the limbic system and prefrontal cortex in primates are discussed with regard to the findings of previous neurophysiological studies in which neuronal responses in these brain regions were analyzed in monkeys and rats.
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Awake surgery has been reported to play a role in the safe removal of brain tumors and detection of the functional localization of the cortex or neuronal tracts. In our hospital, from November 2004 to May 2007, we performed awake surgery with continuous tasks in 33 cases of brain tumors within or near the primary motor area (M1). The relationship between the extent of resection and postoperative motor function in awake surgery cases was compared with that in cases of surgery under general anesthesia, which were performed prior to November 2004. ⋯ Moreover, various new findings regarding the function of the cortex or neuronal tract have been reported in awake surgery. We discussed the advantages and future directions of awake surgery. In conclusion, awake surgery plays an important role in neurosurgery and neuroscience.
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Review Case Reports
[Different stages of human memory consolidation system deficits revealed by patients with epileptic amnesia].
Some patients with temporal lobe epilepsy display an atypical memory disorder known as very long-term amnesia or accelerated forgetting. The characteristics of the study patients were as follows: First, they could retain information long after the test was adminstrated; however, several weeks later, they could not remember the information (long-term anterograde amnesia: LAA). Second, they showed dense retrograde amnesia for decades (long-term retrograde amnesia: LRA). ⋯ However, there have been no reports regarding the effects of such drugs on LRA. In this report, we show 2 patients who were in the initial stage of long-term amnesia and epilepsy in late adult life, and the effect of an AED on LAA and LRA. We found that an AED prevented LAA but not LRA, suggesting that LAA and LRA were different memory consolidation system dificits and that accelerated forgetting was treatable, but retrograde amnesia was an irreversible process.
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Most of our motor skills are acquired through learning. Although the cerebellum is established as the critical site for motor learning, the precise mechanism underlying acquisition and consolidation of motor memory is a topic of on-going debate. We examined the role of the cerebellum in acquisition and storage of motor memory by using adaptations of horizontal vestibulo-ocular reflex (VOR) and optokinetic response (OKR) eye movements in mice and monkeys. ⋯ We further revealed that long-term depression (LTD) of parallel fiber-Purkinje cell synapses plays a critical role in both the day- and week-long adaptations. These results suggest that the trace of motor memory is initially acquired in the cerebellar cortex, and later transferred to the cerebellar/vestibular nuclei for consolidation. LTD plays an essential role in both the acquisition and consolidation of motor memory.