Human autonomic and somatosensory neurophysiology - Macefield group

Get in touch | Our people | Our work |  Our achievements | Publications

Our lab uses invasive and non-invasive methods to explore the neurophysiology of the autonomic and somatosensory nervous systems in humans. Much of our work involves inserting tungsten microelectrodes percutaneousy into peripheral nerves, such as the median or ulnar nerves in the upper arm or wrist, the common peroneal or tibial nerves at the knee or the posterior tibial or sural nerves at the ankle. Most recently, we have extended this work to the vagus nerve in the neck. We also use brain imaging to explore how the brain processes pain and to understand the underlying changes in the brain in cardiovascular disease, migraine and chronic regional pain syndrome. Our lab is committed to providing a deep understanding of both normal physiology and pathophysiology in humans.

Get in touch

Whether you want to be involved in our research, you wish to study with us, you want to collaborate with us or donate to our work, we would be delighted to hear from you.  Email us – vaughan.macefield@monash.edu

Our people

Group Head

Our Work

Our lab performs single-unit nerve recordings from type-identified myelinated sensory axons supplying muscle, skin or joints to understand how forces applied to the hand, for example, are encoded by specific mechanoreceptors in the skin. We can also record from muscle spindle afferents to understand how these intramuscular stretch receptors contribute to proprioception and somatosensory control.

We can also record from unmyelinated axons (C-fibres), both sensory (nociceptors and thermoreceptors) and motor (postganglionic sympathetic axons). Recently, we made the first recordings from the human vagus nerve, by inserting a tungsten microelectrode into the neck under ultrasound guidance. Using this novel approach, we can record from sensory endings in the heart, lungs and airways as well as parasympathetic axons to the heart.

Our lab also uses functional magnetic resonance imaging (fMRI), combined with nerve recordings, to identify cortical and subcortical regions responsible for the generation of sympathetic outflow in health and disease. In addition, we use fMRI to assess how the brain processes pain originating in muscle or skin, both from the limbs and the face. We use experimental models of muscle pain, such as intramuscular infusion of hypertonic saline, or natural models of pain, such as migraine or chronic regional pain syndrome. While we use the 3T MRI facility on Level 4 of The Alfred Centre for much of our work, we also use ultra-high field (7T) MRI facility at Melbourne University.

We also use brain stimulation, e.g. transcranial alternating current stimulation (tcACS) or transcranial magnetic stimulation (TMS), to interrogate the dorsolateral prefrontal cortex (dlPFC), and how it affects sympathetic outflow to muscle or skin.

Our Achievements

For his work on developing the methodology for recording from the human vagus nerve, Vaughan Macefield was awarded the 2022 NHMRC Warren and Marshall Ideas Grant Award for the highest-ranking Ideas Grant. He was also the 2022 recipient of the NHMRC Warren and Marshall Innovation Award for the most innovative and potentially transformative Ideas Grant.

Publications

Below is a selection of some of the published studies reflecting our high-impact work. For a full list of our publications, please visit Pubmed.

Sensorimotor control in the congenital absence of functional muscle spindles. 2023. Macefield VG, Smith LJ, Norcliffe-Kaufmann L, Palma JA, Kaufmann H. Exp Physiol. 2023.

The role of the dorsolateral prefrontal cortex in control of skin sympathetic nerve activity in humans. 2023. Wong R, Sesa-Ashton G, Datta S, McCarthy B, Henderson LA, Dawood T, Macefield VG. Cereb Cortex. bhad112.

Stimulation of the dorsolateral prefrontal cortex modulates muscle sympathetic nerve activity and blood pressure in humans. 2022. Sesa-Ashton G, Wong R, McCarthy B, Datta S, Henderson LA, Dawood T, Macefield VG.  Cereb Cortex Commun. 3(2):tgac017.

Brain and cardiovascular-related changes are associated with aging, hypertension, and atrial fibrillation. 2022. Rim D, Henderson LA, Macefield VG. Clin Auton Res. 32(6):409-422.

Structure and functions of the vagus nerve in mammals. 2022. Ottaviani MM, Macefield VG. Compr Physiol. 12(4):3989-4037.

Recording and quantifying sympathetic outflow to muscle and skin in humans: methods, caveats and challenges. 2021. Macefield VG. Clin Auton Res. 31(1):59-75.

In vivo recordings from the human vagus nerve using ultrasound-guided microneurography. 2020. Ottaviani MM, Wright L, Dawood T, Macefield VG. J Physiol. 598(17):3569-3576. doi: 10.1113/JP280077. Epub 2020 Jul 1. PMID: 32538473.

Differences in regional grey matter volume of the brain are related to mean blood pressure and muscle sympathetic nerve activity in normotensive humans. 2020. Kobuch S, Fatouleh RH, Macefield JM, Henderson LA, Macefield VG.  J Hypertens. 2020 38(2):303-313.

Identification of the human sympathetic connectome involved in blood pressure regulation. 2019. Macefield VG, Henderson LA. Neuroimage. 202:116119.

Functional properties of human muscle spindles. 2018. Macefield VG, Knellwolf TP. J Neurophysiol. 120(2):452-467.