Effect of chondroitin sulfate on murine splenocytes sensitized with ovalbumin

Precursors for Thy-1(+) dendritic epidermal T cells (DETC) develop as Vgamma3(+) T cells in the fetal thymus and become distributed in the adult skin. DETC are variably distributed from site to site and from strain to strain. To elucidate the basis of strain variation, we first compared the density of DETC in the ear epidermis among different mouse strains. In the ear epidermis, we detected the highest level of DETC in C57BL/6 mice, intermediate levels in C3H and CBA/J mice, and the lowest levels in other strains including BALB/c and 129 mice. Although BALB/c and 129+Ter/Sv mice showed higher levels of DETC in the abdomen than in the ear, the levels were significantly lower than C57BL/6 mice. Furthermore, in neonatal abdominal epidermis we detected considerably lower numbers of DETC in BALB/c and 129+Ter/Sv mice than in C57BL/6 mice. In contrast, Vgamma3(+) DETC precursors in the fetal thymus are rather increased in 129+Ter/Sv mice. These results suggest that fewer DETC precursors are seeded in the neonatal skin of BALB/c and 129+Ter/Sv mice and that their expansion in the skin during neonatal to adult stages does not reach the levels in C57BL/6 mice.     

Mirror visual feedback can induce motor learning in patients with callosal disconnection

Mirror therapy using mirror visual feedback (MVF) has been applied to the stroke rehabilitation of hemiparesis. One possible mechanism of mirror therapy is the functional interhemispheric connectivity between sensorimotor areas via corpus callosum. To test this hypothesis, we investigated the MVF-induced motor learning in 2 patients with callosal disconnection. Callosal connection in patients was evaluated by clinical measures and the interhemispheric inhibition (IHI) using transcranial magnetic stimulation. Both patients suffered from somatosensory cognitive disconnection, and one showed the loss of IHI. Motor training with MVF significantly improved the motor behavior of both patients. Extending our previous study, the results of callosal patients suggested that the visual feedback through a mirror might play the crucial important role for the improvement of motor performance, rather than interhemispheric interaction via corpus callosum.     

Alexithymia and regional gray matter alterations in schizophrenia

Alexithymia is characterized by deficits in emotional self-awareness. Although alexithymia refers to a deficit in recognizing one's own emotions, some studies have focused on the relation between alexithymia and impaired social cognition. An association between alexithymia and schizophrenia has been previously reported, but the brain structures involved remain unclear. The present study investigated associations between alexithymia and specific brain structures to determine whether these regions overlapped with key structures underlying social cognition. Twenty-one patients with schizophrenia and 24 age-, gender- and education level-matched healthy controls underwent structural magnetic resonance imaging. Alexithymia was assessed using the 20-item Toronto Alexithymia Scale (TAS-20). We applied voxel-based morphometry to investigate the correlation between TAS-20 scores and regional brain alterations. TAS-20 scores were significantly higher in patients than controls. Bilateral ventral striatum and left ventral premotor cortex volumes were negatively correlated with TAS-20 total scores in controls, while left supramarginal gyrus (SMG) volume was negatively correlated with TAS-20 total scores in patients. These results suggest that schizophrenia is associated with alexithymia, and that gray matter alterations of the left SMG constitute a key pathology underlying alexithymia in schizophrenia. This association may be related to deficits in self-other distinction, self-disturbance, and language processing in schizophrenia.     

Neuroimaging of L-dopamine and dopamine agonist therapy – revisited

Treatment of Parkinson's disease (PD) is improving and we can choose a variety of drugs and surgical procedures for appropriate stages of the disease. However, we depend upon clinical signs and symptoms as well as patient reports to evaluate such issues. While neurochemical research into the etiological aspects of PD has been expanding, imaging is still under investigation. Here, I summarize the results of studies with regard to imaging of dopaminergic systems, and discuss the key points for imaging of PD with respect to treatment evaluation.     

Effects of regularity on the processing of sound omission in a tone sequence in musicians and non‐musicians

Numerous studies have reported that perceptual grouping affects the pre‐attentive processing of sound omission in a sequence of tones. However, it remains unclear whether or not the perceptual grouping and musical experience affect the attentive processing of sound omission. To this end, we created a sequence of loud (L) and soft (S) tones grouped as ‘LLSLLS…’ and a random sequence of the L and S tones. The omission of the L tones was inserted pseudo‐randomly in the random sequence, and there were two positions at which it was inserted. For within‐group omission, the omission was after the first L tone within the ‘LLS’ pattern. For between‐group omission, the omission was inserted between the patterns. The brain response to the omission in musicians and non‐musicians was measured using magnetoencephalography. During the magnetoencephalography measurement, the subjects' performance in a task to detect the omission was faster in the random sequence than in the group sequence. Source analysis showed that the omission in the random sequence caused greater activity than that in the group sequence. The increase was found in the right inferior parietal lobe in musicians, whereas it was found in the left superior temporal gyrus in non‐musicians. These results suggest that the attentive processing of perceptual grouping might implicate the left superior temporal gyrus or right inferior parietal lobe, depending on musical experience.     

Estimation of skeletal muscle energy metabolism in Machado‐Joseph disease using 31P‐MR spectroscopy

The aim of this study was to determine if muscle energy metabolism, as measured by ³¹P‐magnetic resonance spectroscopy (MRS), is a metabolic marker for the efficacy of treatment of Machado‐Joseph disease (MJD). We obtained ³¹P‐MRS in the calf muscle of 8 male patients with MJD and 11 healthy men before, during, and after a 4 minute plantar flexion exercise in a supine position. The data showed that there was a significant difference between the groups in terms of the PCr/(Pi + PCr) ratio at rest (P = 0.03) and the maximum rate of mitochondrial ATP production (V_max) (P < 0.01). In addition, V_max was inversely correlated with the scale for the assessment and rating of ataxia score (r = ?0.34, P = 0.04). The MJD group also showed a reduction in V_max over the course of 2 years (P < 0.05). These data suggest that this noninvasive measurement of muscle energy metabolism may represent a surrogate marker for MJD. © 2010 Movement Disorder Society