WHAT WE DO
Whether it be walking, running, dancing, or writing, all of our voluntary movements require the precise coordination of numerous muscle groups throughout the body. As the brain generates these motor actions, it must do so in such a way that they are still flexible and robust enough to be maintained when there are sudden changes to the body or external environment.
Consider running along a rocky, uneven path. As your nervous system generates the simple motor commands for running, it must modify each step to precisely place your foot to avoid obstacles, whilst seamlessly responding to any unexpected slip or trip you may make. While you achieve this with little conscious thought, this represents a vast computational challenge for the brain, which must integrate previous experience with many different types of sensory input in order to make the correct adjustments to ongoing motor commands.
Understanding this type of behaviour forms the basis for the research of the Murray research group.
'The Man Who Suddenly Fell Over'
- Michael Andrews
Neural circuits in the brainstem influence spinal motor output and provide the critical link between the volitional and cognitive motor circuits of the cortex and basal ganglia and the motor execution circuits of the spinal cord. In particular, interactions of brainstem circuits with sensory feedback, cortical, cerebellar and basal ganglia circuits provide the main mechanism by which the brain can make online modifications to motor output. The goal of the Murray lab is therefore to understand how the nervous system generates the adaptive and flexible movement that is required for survival in a dynamic environment. We focus on the brainstem as we believe that this region provides the key link between higher and lower motor centres, and by unravelling the logic of brainstem motor circuits we will give ourselves the best opportunity to understand motor control in its entirety.
Anatomy of the human vestibular organs located inside the inner ear (yellow, labelled), adjoining the cochlea (green, labelled). These organs sense angular and linear directional changes by the movement of hair cells (box, inset), and send this information to the brain via the vestibulo-cochlear nerve (pink, labelled). This information is crucial to our sense of balance and for navigating the environment around us.
Schematic drawn by: Amanda Mathews
The lateral vestibular nucleus (LVN) is one of the pathways in the brain that we think helps us maintain our balance as we move. This image shows the location of the LVN (labelled) within the mouse brainstem, and some of the inputs (vestibular, orange; somatosensory, red) and outputs (spinal cord, green) of the pathway.
Schematic adapted from: Witts and Murray, 2019