Director's Seminar Series: Dr Clarissa Whitmire

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Abstract:

Sensory organs provide the sole interface between the brain and the external world. Decades of work have identified how individual peripheral sensory neurons encode well controlled, stereotyped stimuli. In contrast, we know comparatively little about how populations of sensory neurons coordinate their activity to signal biologically meaningful information. This gap is particularly striking for the somatosensory system. Despite the skin being the body’s largest sensory organ, population level sensory signalling during behaviour has remained largely inaccessible. Here, we addressed this by performing in vivo two photon calcium imaging of the fourth lumbar dorsal root ganglion in awake and anesthetized mice expressing calcium indicators in diverse sensory neuron populations. Population recordings have revealed coordinated activity across peripheral sensory neurons in response to thermosensory, mechanosensory, and proprioceptive conditions. Individual neurons exhibited response profiles robustly coupled to the stimuli including applied thermal and mechanical stimuli as well as self-generated phase of movement, with both increases and decreases in activity. These findings provide a new framework for understanding how the peripheral nervous system constructs representations of the external environment through the body, and raise fundamental questions about how these sensory signals are integrated and interpreted by the brain.

Bio:

Dr. Whitmire is a group leader at the Queensland Brain Institute (QBI) and a senior lecturer in Electrical Engineering and Computer Science (EECS) at The University of Queensland (UQ). She is a leading expert in understanding how sensory information is represented along the neuraxis from the neurons in the skin that sense external stimuli to the central representation in the thalamocortical circuit. She operates at the interface of neuroscience and engineering to generate novel insights into information representation in the brain. Her laboratory uses a combination of tools to record from populations of neurons, manipulate the activity of those neurons, and model the underlying neural circuitry. Dr. Whitmire trained as a Biomedical Engineer at North Carolina State University (B. S.) and Georgia Institute of Technology/Emory Universty (Ph.D.). Following postdoctoral work at the Max Delbrück Center for Molecular Medicine, she established her own laboratory at The University of Queensland in 2023.