Congratulations to Dr. Hyungbae Kwon and colleagues whose latest results were recently published in Nature Neuroscience!  

Dr. Seth Blackshaw's group also contributed to this work.

Link to Nature Neuroscience publication: https://www.nature.com/articles/s41593-024-01770-9

This study provides the cellular and circuit level demonstration of behavioral causality in a neuronal ensemble that encodes a goal location during spatial navigation. Understanding neural underpinnings of ‘where-to-go’ decision has been a long-standing challenge in neuroscience, but little is known about a cognitive unit of “goal location” and no study has directly demonstrated a causal role of such cognitive unit in guiding spatial navigation, suggesting current understanding in spatial navigation remains incomplete.

The Kwon lab delineated neuronal mechanisms of goal-memory and memory-guided spatial navigation in the nucleus accumbens (NAc). The Kwon lab showed how dopamine release in the NAc during positive experience at the goal location rapidly forms a goal memory that is reliably manifested to guide spatial navigation upon needs. The study described how a specific spatiotemporal pattern of dopamine signals shapes NAc neuronal population to encode a spatial goal, and the first time goal-directed navigation is fully reconstituted solely by artificially assembling the goal-memory and motivated behavior together. Results report that NAc memory ensemble can control spatial navigation, suggesting a “modular framework of cognition” in memory-guided behaviors.

Figure caption: 

A light-sheet microscope 3D image displays the convergence of dopaminergic transmitter inputs from the ventral tegmental area (green), a midbrain structure associated with reward and motivation, and glutamatergic inputs from the ventral hippocampus (red), an area deep within the brain that helps with navigation, onto the nucleus accumbens. Credit: Kanghoon Jung

Congratulations to Dr. Richard Huganir and colleagues whose latest results on AMPA receptors were just published in Nature!

The following Department of Neuroscience labs also contributed to this work:  Xinzhong Dong, Seth Blackshaw, Dwight E. Bergles, Solange P. Brown

https://www.nature.com/articles/s41586-024-08027-2

The Huganir lab discovered that the presence of calcium-permeable AMPA receptors (CP-AMPARs) contributes to the low feature selectivity of parvalbumin-positive (PV) interneurons across different brain regions and species. The Huganir group found that PV interneurons have a low expression of the GluA2 subunit, leading to an abundance of CP-AMPARs. This low expression is conserved across various species, from ferrets to humans. When CP-AMPARs were replaced with calcium-impermeable AMPARs in PV interneurons, their orientation selectivity in the visual cortex and spatial selectivity in the hippocampus increased. The study also found that inducing CP-AMPAR expression in excitatory neurons, which usually have low CP-AMPAR levels, decreased their orientation selectivity. These findings suggest that CP-AMPARs play a crucial role in maintaining the low selectivity of PV interneurons and that this mechanism is conserved across different species and brain regions.