Lallemend Lab - research focus

We are interested in understanding how the sensory signals are processed to initiate behavioral responses.

Collage of two illustrations.
Left: Modified cross section through a crista ampullaris of the vestibular system (Image: Laura Fontanet). Right: Cross section through dorsal root ganglia showing molecular types of neurons (Image: Haohao Wu).

Research focus

Our research addresses the development, organization and function of the neuronal circuits that underlie auditory perception and proprioception (or the sense of body position).

The sensation and processing of sensory information are necessary for almost every activity that we perform and affect our behavior. In this context, research in my lab is focusing on understanding the organization principles, function and plasticity of the sensory circuits. We leverage advanced single cell transcriptomics and circuit-interrogation technology to identify the structurally- and molecularly-defined neuronal elements for auditory perception and proprioception, in physiological and pathological conditions. We are also exploring the mechanisms by which experience-driven neuronal activity shapes the developing mammalian sensory systems. We are very interested in understanding whether such neuronal plasticity is retained in adult and if its modulation can lead to a gain of sensory function or to its deterioration during disorders or with aging.  

To this end, we have worked to identify and characterize the various cell types constituting the primary neurons of the peripheral auditory system, also called the sensory neurons of the cochlea, and of the proprioceptive system, i.e. the proprioceptive neurons located in the sensory ganglia along the spinal cord. The cochlear neurons encode sound signals and convey the auditory information to the central nervous system via the auditory nerve. The proprioceptive neurons are activated by muscle activity and provide sensory feedback to the spinal cord and higher brain center. Proprioception is mostly an unconscious sense, yet it is necessary for coordinating all our movements. To address the role of each individual type of sensory cells in processing auditory and proprioceptive sensation, we are using a combination of high precision micro-surgery and advanced viral-based trans-synaptic tract tracing techniques. State-of the art reconstruction of the brain connectivity can then disentangle the circuitry down to the cellular level. Eventually, identified circuits elements are functionally tested using intersectional mouse genetics and behavioral assessments of motor coordination as well as auditory measurements.

Eventually, we aim at increasing our understanding of how the brain receives and integrates information from several modalities to initiate appropriate behavioral response.