Gary Marsat, PhD

Research Interests

Our research focuses on understanding how sensory signals are processed by the nervous system. A key element of this endeavor is to understand how neural codes package the sensory information efficiently. Some would describe this task as "cracking the neural code". Using gymnotiform weakly electric fish as a model system we concentrate on characterizing how communication signals are encoded in the sensory system. To guide behavior, the relevant information present in these signals must be extracted and transmitted to higher brain areas. From the receptors, to the primary sensory area in the hindbrain (ELL) to midbrain and forebrain, the transformations that the signal undergoes in each neural population must be understood.

The ELL has been the focus of our research so far. We use a combination of in vivo electrophysiology, computational neuroscience tools, behavioral assays, histology, imaging, pharmacological manipulations and comparative studies. We characterized the way ELL neurons encode communication signals. We revealed how cellular and network dynamics influence the transformation operated by the system. We demonstrated how the coding scheme and the transformation implemented by the system are tailored to the behavioral aptitudes of the fish. We are examining how spatial information and localization of a social partner is shaped by the network and population dynamics of sensory neurons. The research in our lab is at the intersection of three connected areas of neuroscience: Systems Neuroscience, Computational Neuroscience and Neuroethology. For this reason, we find it very important to relate neural activity with behavior, to characterize mathematically the process implemented by the neural network, and identify the cellular and network mechanisms that dictate how signals are processed.

For more information visit: https://www.marsat.org/research

Publications

Selected Publications

• Milam O, Ramachandra KL and Marsat G (2019).  Behavioral and neural aspects of the spatial processing of conspecifics in the electrosensory systems. Behav Neurosci, 133(3): 282-296
• Motipally SI, Allen KM, Williamson DK and Marsat G (2019). Differences in sodium channel densities in the apical dendrites of pyramidal cells of the electrosensory lateral line lobe. Front. Neural Circuits, 13:41
• Allen KM and Marsat G (2019). Neural processing of communication signals: The extent of sender-receiver matching varies across species of Apteronotus. eNeuro, 6(2):eneuro0392-18.2019
• Neeley B, Overholt T, Artz E, Kinsey S and Marsat G (2018). Behavioral effect of cannabinoid agonist on the social and communication behavior of weakly electric fish as a function of context. Brain Behav & Evol 91:214-227
• Allen KM and Marsat G (2018). Task-specific sensory coding strategies are matched to detection and discrimination performance. J Exp Biol 221:jeb170563
• Marsat G, Longtin L and Maler L (2012). Cellular and circuit properties supporting different sensory coding strategies in electric fish and other systems. Curr Opin Neurobiol, 22:1-7.
• Bol K, Marsat G, Harvey-Girard E, Longtin A and Maler L (2011). Frequency-tuned cerebellar channels and burst-induced LTD lead to the cancellation of redundant sensory inputs. J Neurosci, 31:11028-11038.
• Marsat G and Maler L (2010). Neural heterogeneity and efficient population codes for communication signals. J Neurophysiol, 104:2543-2555.
• Marsat G** and Pollack GS (2006). A behavioral role for feature detection by sensory bursts. J Neurosci, 26:10542-10547. 

Full list of publications: https://www.marsat.org/publications