Reinforcement learning for a biped robot based on a CPG-actor-critic method.

Animals' rhythmic movements, such as locomotion, are considered to be controlled by neural circuits called central pattern generators (CPGs), which generate oscillatory signals. Motivated by this biological mechanism, studies have been conducted on the rhythmic movements controlled by CPG. As an autonomous learning framework for a CPG controller, we propose in this article a reinforcement learning method we call the "CPG-actor-critic" method. This method introduces a new architecture to the actor, and its training is roughly based on a stochastic policy gradient algorithm presented recently. We apply this method to an automatic acquisition problem of control for a biped robot. Computer simulations show that training of the CPG can be successfully performed by our method, thus allowing the biped robot to not only walk stably but also adapt to environmental changes.     

Neocortical gray matter volume in first-episode schizophrenia and first-episode affective psychosis: a cross-sectional and longitudinal MRI study.

BACKGROUND: Overall neocortical gray matter (NCGM) volume has not been studied in first-episode schizophrenia (FESZ) at first hospitalization or longitudinally to evaluate progression, nor has it been compared with first-episode affective psychosis (FEAFF). METHODS: Expectation-maximization/atlas-based magnetic resonance imaging (MRI) tissue segmentation into gray matter, white matter (WM), or cerebrospinal fluid (CSF) at first hospitalization of 29 FESZ and 34 FEAFF, plus 36 matched healthy control subjects (HC), and, longitudinally approximately 1.5 years later, of 17 FESZ, 21 FEAFF, and 26 HC was done. Manual editing separated NCGM and its lobar parcellation, cerebral WM (CWM), lateral ventricles (LV), and sulcal CSF (SCSF). RESULTS: At first hospitalization, FESZ and FEAFF showed smaller NCGM volumes and larger SCSF and LV than HC. Longitudinally, FESZ showed NCGM volume reduction (-1.7%), localized to frontal (-2.4%) and temporal (-2.6%) regions, and enlargement of SCSF (7.2%) and LV (10.4%). Poorer outcome was associated with these LV and NCGM changes. FEAFF showed longitudinal NCGM volume increases (3.6%) associated with lithium or valproate administration but without clinical correlations and regional localization. CONCLUSIONS: Longitudinal NCGM volume reduction and CSF component enlargement in FESZ are compatible with post-onset progression. Longitudinal NCGM volume increase in FEAFF may reflect neurotrophic effects of mood stabilizers.     

Klinefelter's syndrome complicated with West syndrome in a 4-month-old boy

We, for the first time, report a boy with West syndrome associated with Klinefelter's syndrome. He developed episodes of repetitive tonic spasms at the age of 4 months. He had developmental delays and hypsarrhythmia on interictal electroencephalography recording. His karyotype turned out to be 47, XXY, while we failed to observe anomalies in his appearance. Adrenocorticotropic hormone therapy with antiepileptic drugs resulted in cessation of tonic spasms, and his developmental quotient was improved by the age of 1 year. Further studies are needed to determine the causal association between West syndrome and Klinefelter's syndrome.     

Initial motor impairment influences activation pattern of motor recovery

OBJECTIVES: We investigated the functional magnetic resonance imaging (fMRI) activation pattern of a motor task in patients with acute subcortical lesions to examine the relationship between activation pattern and recovery of motor impairment. METHODS: Five patients (one with subcortical infarction and four with thalamic hemorrhage) were examined using fMRI 1 month after the insult. Impairment was assessed by the Medical Research Council motor strength classification (MRC). One patient with severe motor deficits was also studied at 4 months when her motor deficits improved up to MRC grade 4. RESULTS: Three patients with relatively mild deficits (MRC grade 3 or 4) at their onsets, improved fully up to grade 5 within 1 month. FMRI performed at 1 month showed activation in the contralateral primary motor cortex and supplementary motor area (SMA), but no significant activation was seen on the ipsilateral unaffected side. Two patients with severe motor impairment (MRC grade 1) improved up to 3 and 4 of MRC at 1 month or later. They showed activation of the ipsilateral premotor area as well as contralateral primary motor cortex and SMA. One of them, whose severe motor deficit improved at 4 month, also showed activation of the ipsilateral postcentral gyrus and the activated area expanded longitudinally corresponding with her functional recovery. DISCUSSION: Our study demonstrates that the fMRI pattern varies according to functional recovery, suggesting the importance of the ipsilateral premotor area and postcentral gyrus especially for those patients with severe motor impairment initially.     

No association between the Clara cell secretory protein (CC16) gene polymorphism and personality traits

Clara cell secretory protein (CC16) is an anti-inflammatory protein expressed in the respiratory tract. Several studies have suggested the association between CC16 and mental disturbances, such as schizophrenia, depression, and post-traumatic stress disorder. In the present study, we investigated the association between the CC16 gene A38G polymorphism and personality traits in 214 healthy Japanese subjects. Personality traits were evaluated by using the Revised NEO Personality Inventory (NEO PI-R) and the State-Trait Anxiety Inventory (STAI). As a result, no significant association was observed between the genotypes and the scores of the NEO PI-R or the STAI. The present results suggest that CC16 may not have a major role in the development of personality traits.     

Silent information regulator, Sirtuin 1, and age-related diseases

Sirtuin 1 (SIRT1), a member of the silent information regulator 2 in mammals, has recently been found to be involved in age-related diseases, such as cancer, metabolic diseases, cardiovascular disease, neurodegenerative diseases, osteoporosis and chronic obstructive pulmonary disease (COPD), mainly through deacetylation of substrates such as p53, forkhead box class O, peroxisome proliferator activated receptor γ co-activator 1α, and nuclear factor-κB. It is widely reported that SIRT1 can promote not only carcinogenesis but also metastasis and insulin resistance, andhave beneficial effects in metabolic diseases, mediate high-density lipoprotein synthesis and regulate endothelial nitric oxide to protect against cardiovascular disease, have a cardioprotective role in heart failure, protect against neurodegenerative pathological changes, promote osteoblast differentiation, and also play a pivotal role as an anti-inflammatory mediator in COPD. However, there are controversial results suggesting that SIRT1 has an effect in protecting against DNA damage and accumulation of mutations, and preventing tumorigenesis. In addition, a high level of SIRT1 can induce cardiomyopathy and even heart failure. This article reviews recent developments relating to these issues.     

Reduction in QSART and vasoactive intestinal polypeptide expression in the skin of Parkinson's disease patients and its relation to dyshidrosis

Background:  With regards to dyshidrosis in Parkinson's disease (PD), there is no established and consistent view on the occurrence sites, frequency and etiology, although there have been several reports on hypohidrosis of the limbs and sudoresis on the face/cervical region.
Methods:  Hydrosis in the forearms of PD patients and healthy individuals were compared by quantitative sudomotor axon reflex test (QSART). The expression of various neuropeptides and α-synuclein was examined with immunohistochemical staining.
Results:  There was a significant reduction in QSART of PD patients but not of healthy controls. Reduced expression of vasoactive intestinal polypeptide (VIP) was also detected in the sweat glands of PD patients.
Conclusion:  Reduction in QSART and VIP expression in the sweat glands might be involved in the dyshidrosis of PD patients.