Background: Age-related loss of muscle strength is often explained by the concomitant reduction in muscle mass, however the former appears to decline more rapidly than the latter and this discordant relationship is poorly described, and often entirely overlooked. Alterations in neural mechanisms are a likely candidate here; work from our group has identified striking age-related differences in motor nerve/muscle recruitment strategies, including reduced firing frequency, diminished transmission stability at the neuromuscular junction (NMJ), and reduced heterogeneity of motor unit size during voluntary contractions in older adults. Thus, neural alterations must be considered.
Whilst resistance exercise training (RET) improves the ability to recruit/activate muscle (so called ‘neural drive’), it is not always feasible for older frail individuals to undergo strenuous exercise. Therefore, new interventions are required. Electrical stimulation (ES) targeting sensory and/or motor neurons has already been shown to increase the excitability of spinal circuits as well as motor neuron pools and this may result in increased recruitment of motor units when applied during exercise, subsequently enhancing exercise efficiency- however evidence for this is lacking.
There is a critical need to address age-related alterations in motor pathways, from the motor cortex to muscle fibres, that negatively impact muscle strength and control, and to offer feasible, effective interventions for frail older individuals, especially those that offer potential translation to clinical settings.
The proposed project will investigate age-related decrements in neural drive and neuromuscular function in humans, and will apply a number of appropriate interventions. The successful candidate will join a leading group in the field of musculoskeletal ageing, and will be trained in a range of techniques including intramuscular electromyography (iEMG), transcranial magnetic stimulation (TMS), immunohistochemistry and further techniques of molecular biology.
Applicants should have a strong background in human physiology, and ideally a background in neuromuscular physiology. They should have a commitment to research in age-related neuromuscular disorders and hold or realistically expect to obtain at least an Upper Second Class Honours Degree in a relevant subject. A relevant Master’s degree would be an advantage (not essential). The supervisory team and project will produce the highly skilled physiologist that is acutely required to meet the demands of academia and biomedical musculoskeletal focused research.
How to apply
Informal enquiries should be directed to Dr Mathew Piasecki, [email protected]
Applications should be directed to Lisa Fuller (email – [email protected]
). To apply, please send:
• A detailed CV, including your nationality and country of birth;
• Names and addresses of two referees;
• A covering letter highlighting your research experience/capabilities;
• Copies of your degree certificates with transcripts;
• Evidence of your proficiency in the English language, if applicable.
This studentship is full-time and will begin on 1st of October 2019
Interviews will take place on 21st March 2019
Piasecki M, Ireland A, Piasecki J, Stashuk DW, Swiecicka A, Rutter MK, Jones DA & McPhee JS (2018). Failure to expand the motor unit size to compensate for declining motor unit numbers distinguishes sarcopenic from non-sarcopenic older men. J Physiol 596, 1627–1637.
Piasecki M, Ireland A, Stashuk D, Hamilton-Wright A, Jones DA & McPhee JS (2016). Age-related neuromuscular changes affecting human vastus lateralis. J Physiol 594, 4525–4536.
Piasecki M, Ireland A, Jones DA & McPhee JS (2016). Age-dependent motor unit remodelling in human limb muscles. Biogerontology 17, 485–496.
Chiou SY, Hurry M, Reed T, Quek JX & Strutton PH (2018). Cortical contributions to anticipatory postural adjustments in the trunk. J Physiol; DOI: 10.1113/JP275312.
Wilkinson DJ, Piasecki M & Atherton PJ (2018). The age-related loss of skeletal muscle mass and function: measurement and physiology of muscle fibre atrophy and muscle fibre loss in humans. Ageing Res Rev; DOI: 10.1016/j.arr.2018.07.005.
Mcphee JS, Cameron J, Maden-Wilkinson T, Piasecki M, Yap MH, Jones DA, Degens H (2018). The Contributions of Fiber Atrophy, Fiber Loss, In Situ Specific Force, and Voluntary Activation to Weakness in Sarcopenia. J Gerontol A Biol Sci Med Sci 00, 1–8.