Tanshinone IIA protects against dopaminergic neuron degeneration via regulation of DJ-1 and Nrf2/HO-1 pathways in a rodent model of Parkinson’s disease

Purpose: To study the potential neuroprotective effects of tanshinone IIA, a diterpene quinone, in an experimental model of 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced Parkinson disease (PD). Methods: Mice (C57BL/6) were administered freshly-prepared MPTP at a dose of 20 mg/kg body weight intraperitoneally, 4 times at 2-h intervals, to induce PD. Doses of 12.5, 25 and 50 mg/kg tanshinone IIA were administered to the mice as treatments for PD. Pole and Rota-rod tests were carried out to assess muscular coordination and bradykinesia. Protein expressions, reactive oxygen species (ROS) and malonaldehyde and other parameters were evaluated. Results: Tanshinone IIA at doses of 12.5, 25 and 50 mg/kg reduced deficits in muscular coordination and improved learning ability of MPTP-treated mice. It also reduced loss of tyrosine hydroxylase (TH)- positive neurons following MPTP-induction. Tanshinone IIA regulated apoptotic pathway proteins, i.e., Bax and Bcl-2, and inhibited the translocation of Cyt C to the mitochondria. Oxidative stress induced by MPTP was significantly inhibited by tanshinone IIA via up-regulation of DJ-1/Nrf2 /HO-1 expression and reduction of ROS and MDA levels. Brain tissue total glutathione content was increased by tanshinone IIA treatment. Conclusion: Tanshinone IIA effectively improves antioxidant status and reduces neuronal loss following MPTP treatment. These results indicate that tanshinone IIA exerts protective effects in MPTPinduced PD in mice. Thus, tanshinone IIA has a good potential for use as a therapy for PD.

Speaking and Hearing With an Accent

When we speak a second language, we tend to do so with an accent. An accent is a change of the sounds of the second language, often the result of the influence of the first language. For example, an English speaker might produce French with English “r” sounds. Accents result from more than just poor muscular coordination. Second-language speakers are drawing on the unconscious rules that they already know about their first language. This body of knowledge influences not only how people speak a second language but also how they hear it. If a Japanese speaker is not accurately producing a distinction between an “l” and “r” sound, it is likely that the same individual will have difficulty accurately hearing the difference between the two sounds. Ultimately, bilingualism is a natural state for the human brain, even when we are speaking or listening with an accent.

The Role of Dental Occlusion and Neuromuscular Behavior in Professional Ballet Dancers’ Performance: A Pilot Study

Clinical practice and some scientific evidence seem to suggest that there is some kind of relationship between the components that form the postural chain. For professional dancers, good posture and balance are essential. The aim of the present retrospective study is to evaluate whether gnathological treatment could have an impact on the postural balance and sports performance of professional ballet dancers. Electromyographic (EMG) data and balance tests were recorded before and after six months of treatment with a customized occlusal splint. Twenty athletes were examined during ballet exercises in terms of balance and speed of execution by two experienced clinicians. The results showed statistically significant changes for all EMG tests carried out and the Flamingo Balance Test. It appears that the use of a customized occlusal device improved neuro-muscular coordination and the overall performance of dancers.

Cerebellum: Its Anatomy, Functions and Diseases

Cerebellum is the largest part of the hindbrain and weighs about 150 g. It is enshrined in posterior cranial fossa behind the pons and medulla oblongata and separated from these structures by cavity of fourth ventricle. It is connected to brainstem by three fibre tracts known as cerebellar peduncles. Cerebellum controls the same side of body. It precisely coordinates skilled voluntary movements by controlling strength, duration and force of contraction, so that they are smooth, balanced and accurate. It is also responsible for maintaining equilibrium, muscle tone and posture of the body. This is achieved through the use of somatic sensory information in modulating the motor output from the cerebrum and brainstem. Sherrington regarded cerebellum as the head ganglion of the proprioceptive system. Dysfunction of cerebellum along with degenerative diseases of cerebellum such as spinocerebellar ataxia, multiple sclerosis, malignant tumours, etc. may culminate into disequilibrium, hypotonia, difficulty in talking, sleeping, maintaining muscular coordination and dyssynergia which at times may be life threatening. Hence, knowledge of anatomy of cerebellum is imperative for neuroanatomists and neurosurgeons.

The Use of the Test for Oral Muscular Coordination Ability to Increase the Level of Adaptive Capacity of Oral Cavity Organs to Prosthodontic Treatment of Patients with Completely Absent Dentition

Increase in the level of adaptive capacity of oral cavity organs to the prosthodontic treatment of patients with completely absent dentition is one of the urgent problems of modern dentistry. In order to increase the level of adaptability to complete removable laminar dentures, a set of standard samples according to H. Landt was used to test the ability for precise coordination of masticatory muscles – the MA-test (Muscular-Ability) as a means of a group of muscles stimulation providing precise coordination of masticatory muscles. This adaptation process was called MA-stimulation. The level of adaptive capacity of the oral cavity organs was studied using oral stereognosis. The criteria for oral stereognosis assessment included the average time of one sample determination (sec) and the correctness of the samples determination (%). In order to achieve the objective, we conducted a study of tactile sensitivity in the oral cavity using oral stereognosis in 90 patients with completely absent dentition who applied for the prosthodontic retreatment. The patients’ age ranged from 45 to 89 years. The patients were divided into two groups. Group I included 30 patients who underwent the prosthodontic treatment without preliminary MA-stimulation. Group II included 60 patients who underwent MA-stimulation for 14 days before the prosthodontic treatment. According to the results of oral stereognosis in Group II of patients, the average time of one sample determination after fourteen days of MA-stimulation decreased by 24.5% (p˂0.05) and the index of correctness of the samples determination increased by 32.0% (р˂0.001); the average time of one sample determination decreased by another 19.3% in 1 month after the prosthodontic treatment, and it decreased by 17.4% (р˂0.05) in 3 months after the prosthodontic treatment; the index of the correctness of the samples determination increased by 17.5% (p˂0.001) and 10.5% (p˂0.01) respectively in 1 and 3 months after the prosthodontic treatment. Oral stereognosis indices changed significantly only in 1 month after the prosthodontic treatment in Group I of patients who did not undergo MA-stimulation: the average time of one sample determination decreased only by 14.7% (p˂0.05), and the index of correctness of the samples determination increased only by 24.5 (p˂0.05). According to the results of the research, MA-stimulation is advisable to be included into the prosthodontic treatment of the patients with completely absent dentition as a means of increasing the adaptive capacity of the oral organs.

Muscular coordination during vertical jumping

The musculoskeletal system has a relatively large number of mechanical degrees of freedom. In order to permit coordinated movement, it is thought that these degrees of freedom are constrained, reducing the complexity of the motor control problem. For this reason, principal component analysis can be a powerful technique for understanding the organisation of movement by calculating the number of functional degrees of freedom present in a particular movement task. In this study, we used principal component analysis to find the number of functional degrees of freedom exhibited during vertical jumping. We applied the technique to both the inter-segmental moments and the muscle forces (that were estimated based upon a publicly available musculoskeletal model of the lower limb). We found that over 90% of the variance in the 3 dimensional inter-segmental moments could be described by 3 principal components, suggesting the presence of 3 functional degrees of freedom. Similarly, only 4 principal components were required to capture 90% of the variance in muscles forces. These results suggest that there is a marked inter-individual similarity in both moments and muscle forces during vertical jumping.