Activation of M1 cholinergic receptors in mouse somatosensory cortex enhances information processing and detection behaviour

To optimise sensory representations based on environmental demands, the activity of cortical neurons is regulated by neuromodulators such as Acetylcholine (ACh). ACh is implicated in cognitive functions including attention, arousal and sleep cycles. However, it is not clear how specific ACh receptors shape the activity of cortical neurons in response to sensory stimuli. Here, we investigate the role of a densely expressed muscarinic ACh receptor M1 in information processing in the mouse primary somatosensory cortex and its influence on the animal's sensitivity to detect vibrotactile stimuli. We show that M1 activation results in faster and more reliable neuronal responses, manifested by a significant reduction in response latencies and the trial-to-trial variability. At the population level, M1 activation reduces the network synchrony, and thus enhances the capacity of cortical neurons in conveying sensory information. Consistent with the neuronal findings, we show that M1 activation significantly improves performances in a vibriotactile detection task.

Ergonomic risk assessment of musculoskeletal discomforts among young Indian rowers

BACKGROUND: Rowing requires synchronized, forceful and repetitive muscular movement to propel the boat towards the finish point. This makes rowers prone to musculoskeletal discomfort. The etiology of such musculoskeletal discomfort is multifactorial in nature. Therefore, risk assessment is essential for encouraging enhanced performances. OBJECTIVE: The present study was undertaken to decipher the prevalent areas of discomfort, identify risk factors contributing to discomforts among young Indian rowers and propose a model for the causative factors of discomfort to monitor their performances. METHODS: A self-constructed questionnaire was framed and administered at state level competition. To identify the likely commonalities, the response matrix was subjected to Factor Analysis (FA). Subsequently, Principal Component Regression (PCR) was carried out to identify the influence of ergonomic risk factors with rowing performance parameters. RESULTS: The study identified three major factors: Imprecision Related Factors’ (ImRF), ‘Occupation Related Factors’ (ORF) and ‘Individual Related Factors’ (IRF). The study suggests changes to the training strategies for reducing discomforts from ergonomics risk factors. CONCLUSIONS: The study quantifies major risk factors with the highest loading and proposes an interpretive model. This will be beneficial for formulating the training frameworks and to prepare guidelines for rowers to refrain from discomforts consequently, enhancing performance.

A protocol for simultaneous in vivo juxtacellular electrophysiology and local pharmacological manipulation in mouse cortex

Here, we describe a protocol to simultaneously record and label single cortical neurons in vivo under local application of a chemical such as a receptor agonist. This protocol provides a useful tool to investigate how the chemical of interest affects the processing of sensory information by cortical neurons. The juxtacellular labeling allows identification of the cell type and morphology of the recorded neurons. We draw examples to show pharmacological modulations in encoding of vibrotactile stimuli in the mouse primary somatosensory cortex.

For complete details on the use and execution of this protocol, please refer to Kheradpezhouh et al. (2020).

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In vivo recording of cortical neurons under local pharmacological manipulation

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A pipette pair is used for simultaneous juxtacellular recording and pharmacology

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The recorded neuron is labeled for identification of cell type and morphology

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Establish how the chemical changes the neuronal response function to sensory input

Playing-related musculoskeletal disorders among Indian tabla players

Playing a percussion instrument demands great force and effort, which may make percussionists prone to playing-related musculoskeletal disorders (PRMDs). Of all of the percussion instruments in India, tabla is the most popular. The present study was undertaken to investigate the prevalence of discomforts among professional tabla players. Eighty-five professional tabla players voluntarily participated in the study. The Nordic Musculoskeletal Questionnaire and visual analog scale were administered to all the participants. Demographic details, music-related activities, and symptoms of discomfort were also recorded. It was found that prone anatomical areas were the low back, right shoulder, neck, left shoulder, upper back, and knees. The frequency of discomfort was found to be mostly weekly for the shoulders and monthly for neck, low back, and knees. There was an association between visual analog scale and prevalence of self-reported discomforts in some body parts. It can be said that the prolonged, unsupported, folded-knee sitting posture may be the cause of discomforts.

An integrative approach for evaluating work related musculoskeletal disorders

OBJECTIVES

To develop a framework for evaluating the work related musculoskeletal disorders (WRMSDs).

PARTICIPANTS

The proposed framework was tested on 15~jewellery manufacturing workers working at Chinchpokhli region in Mumbai, India and on 15 students studying in a management institute of Mumbai, India.

METHODS

The framework has been broken into three phases. Phase 1--Ergonomic-risk evaluation; Phase 2--Musculoskeletal Disorders (MSD) evaluation and Phase 3--Clinical examination. Ergonomic-risk evaluation determines the relationship between work relatedness and musculoskeletal disorders. Musculoskeletal Disorders (MSD) evaluation tries to assess the presence of discomforts/disabilities in different body regions, through subjective evaluation tools. Ergonomic-risk evaluation involved QEC, PLIBEL and posture analysis by RULA. Musculoskeletal Disorders (MSD) evaluation involved administration of self reported questionnaires. Clinical examination involved muscle grading by a physiotherapist and back strength measurement.

RESULTS

The framework suggested that ergonomic risk evaluation techniques, self reported body part questionnaires and physical measurement of physiological/biomechanical transients may have a relationship and can be used for the evaluation of work related musculoskeletal disorders.

CONCLUSION

The proposed integrative approach will help in developing stage wise intervention strategies for work related musculoskeletal disorders.

A study of subjective visual disturbances in jewellery manufacturing

Subjective Visual Disturbances are silent adversaries that appear over a period of continued exposure and arise when the visual demands of the tasks exceed the visual abilities of the user. Jewellery manufacturing activity involves precision designs, setting the metal and stones, polishing and filing which requires higher visual demand. Therefore, it is expected that the jewellery manufacturing workers may experience subjective visual disturbances. This study was taken up with the following objectives 1) To study the presence of subjective visual disturbances among jewellery manufacturing workers and compare the same with VDT operators 2) To study the effect of work exposures on subjective visual disturbances and 3) to ascertain whether subjective visual disturbances have any permanent vision related problems. The study was carried out on jewellery manufacturing workers, VDT operators and on graduate students. The symptoms of subjective visual disturbances were identified using a questionnaire developed by Sheedy (2003). Viewing distances were measured and visual angles were calculated. The eye check--ups were also carried out. The subjective visual disturbances were higher in jewellery manufacturing workers. The findings suggest that work exposure has an impact on the causation of subjective visual disturbances. No pathological conditions of the eyes were observed.