Mario Dipoppa (Miller Lab)
Abstract: The role of cell types in the functions of the primary visual cortex

Cortical neurons can be divided into tenths of molecularly defined cell types. However, a mechanistic understanding of how cell types contribute to cortical functions is often lacking due to the intricacy of their recurrent interactions. To address this challenge, we developed data-driven techniques to infer the unknown parameters of the recurrent circuit (Dipoppa et al., 2018, Keller, Dipoppa et al., 2020, Schmidt et al., 2021). The analysis of our circuit models demonstrated that cell types control how visual responses of the primary visual cortex are modulated by the behavioral or visual context. In particular, cell types controlled contextual modulation of visual stimuli through a disinhibitory circuit, by enhancing recurrent excitation from the local Pyramidal neurons (Keller, Dipoppa et al., 2020).

Jeffrey Lopez-Rojas (Siegelbaum Lab)

Abstract: A direct lateral entorhinal cortex to hippocampal CA2 circuit conveys social information required for social memory

The hippocampus is essential for forming and storing declarative memories, including social memory, the ability of an animal to recognize and remember a conspecific. To serve this mnemonic function, the hippocampus relies on a variety of external inputs. Despite recent advances in our understanding of the brain circuits supporting social memory, little is known about the role of the entorhinal cortex, which provides the primary source of multimodal sensory input from neocortex to hippocampus. We found that social memory depends on the direct relay of social information from entorhinal cortex to dorsal CA2. Moreover, the information routed to CA2 is specifically provided by inputs from the lateral entorhinal cortex, rather than from medial entorhinal cortex.