Tonicity response element binding protein associated with neuronal cell death in the experimental diabetic retinopathy

AIM: To study the contribution of tonicity response element binding protein (TonEBP) in retinal ganglion cell (RGC) death of diabetic retinopathy (DR). METHODS: Diabetes was induced in C57BL/6 mice by five consecutive intraperitoneal injections of 55 mg/kg streptozotocin (STZ). Control mice received vehicle (phosphate -buffered saline). All mice were killed 2mo after injections, and the extent of cell death and the protein expression levels of TonEBP and aldose reductase (AR) were examined. RESULTS: The TonEBP and AR protein levels and the death of RGC were significantly increased in the retinas of diabetic mice compared with controls 2mo after the induction of diabetes. Terminal deoxynucleotidyl transferase (TdT) -mediated dUTP nick end labeling (TUNEL) -positive signals co -localized with TonEBP immunoreactive RGC. These changes were increased in the diabetic retinas compared with controls. CONCLUSION: The present data show that AR and TonEBP are upregulated in the DR and TonEBP may contribute to apoptosis of RGC in the DR.close2

Age-Related Changes in Bimanual Instrument Playing with Rhythmic Cueing

Deficits in bimanual coordination of older adults have been demonstrated to significantly limit their functioning in daily life. As a bimanual sensorimotor task, instrument playing has great potential for motor and cognitive training in advanced age. While the process of matching a person’s repetitive movements to auditory rhythmic cueing during instrument playing was documented to involve motor and attentional control, investigation into whether the level of cognitive functioning influences the ability to rhythmically coordinate movement to an external beat in older populations is relatively limited. Therefore, the current study aimed to examine how timing accuracy during bimanual instrument playing with rhythmic cueing differed depending on the degree of participants’ cognitive aging. Twenty one young adults, 20 healthy older adults, and 17 older adults with mild dementia participated in this study. Each participant tapped an electronic drum in time to the rhythmic cueing provided using both hands simultaneously and in alternation. During bimanual instrument playing with rhythmic cueing, mean and variability of synchronization errors were measured and compared across the groups and the tempo of cueing during each type of tapping task. Correlations of such timing parameters with cognitive measures were also analyzed. The results showed that the group factor resulted in significant differences in the synchronization errors-related parameters. During bimanual tapping tasks, cognitive decline resulted in differences in synchronization errors between younger adults and older adults with mild dimentia. Also, in terms of variability of synchronization errors, younger adults showed significant differences in maintaining timing performance from older adults with and without mild dementia, which may be attributed to decreased processing time for bimanual coordination due to aging. Significant correlations were observed between variability of synchronization errors and performance of cognitive tasks involving executive control and cognitive flexibility when asked for bimanual coordination in response to external timing cues at adjusted tempi. Also, significant correlations with cognitive measures were more prevalent in variability of synchronization errors during alternative tapping compared to simultaneous tapping. The current study supports that bimanual tapping may be predictive of cognitive processing of older adults. Also, tempo and type of movement required for instrument playing both involve cognitive and motor loads at different levels, and such variables could be important factors for determining the complexity of the task and the involved task requirements for interventions using instrument playing

Effects of Rhythmic Auditory Stimulation During Hemiplegic Arm Reaching in Individuals with Stroke: An Exploratory Study

SummaryObjective/BackgroundThis study investigated the effects of rhythmic auditory stimulation (RAS) on muscle activity and elbow motion during arm reaching with hemiplegic arm in participants with stroke.MethodsSixteen adults with stroke who resided in a community were recruited in this study. The RAS consisted of sound emitted from a digital metronome. While sitting upright in a chair, participants reached their arms towards a target (a switch on a table) both with and without RAS. The three-dimensional motion analysis system and surface electromyography system were used for measurements during the reaching tasks.ResultsWe found that RAS elicited better performance in reaching movements than those movements performed without RAS. RAS shortened the movement time (p = .002), reduced the change in acceleration (p = .001), increased the elbow extension range of motion (p = .001), increased muscle activation of the triceps brachii (p = .024), and reduced the co-contraction ratio (p = .015) of the affected arm.ConclusionRAS might be a useful technique to facilitate improvements in motor function of the affected arm in patients with stroke