Researchers have discovered that two neural circuits found in the retrosplenial cortex of the brain are closely associated with how we navigate space and store memories. This breakthrough might enable more targeted medical treatments for Alzheimer’s disease and other cognitive impairments by focusing on specific neural circuits.
Researchers from the University of California, Irvine have made a pivotal discovery about two neural circuits in the brain’s retrosplenial cortex that are intricately tied to spatial navigation and memory retention. This finding could pave the way for more targeted medical therapies for Alzheimer’s and similar cognitive disorders by allowing treatments to hone in on specific neural pathways.
A study published in the journal Molecular Psychiatry has pinpointed two distinct RSC pathways, each connected to various brain regions and exhibiting unique input patterns and functions.
“By illustrating how specific circuits in the RSC influence different cognitive functions, our research lays a foundational structure for future investigations and sheds light on how we learn and remember our surroundings,” explained lead author Xiangmin Xu, UC Irvine Chancellor’s Professor of anatomy and neurobiology and head of the Center for Neural Circuit Mapping. “Understanding how conditions like Alzheimer’s affect specific brain areas is a crucial step toward developing new treatment methods.”
The RSC connects to various brain regions, with the research focusing on two primary pathways: M2-projecting, linked to the secondary motor cortex, and AD-projecting, associated with the anterior thalamus. M2 neurons play a role in translating spatial thoughts into action, whereas AD neurons are essential for recalling specific locations.
To investigate these circuits, the researchers employed advanced viral tools to individually map and manipulate the connections and assess the outcomes. They discovered that inhibiting M2-projecting neurons impaired the ability to remember where objects were situated and to link specific places with actions. On the other hand, suppressing AD-projecting neurons only affected the memory of object locations.
“We are building upon these findings by exploring more pathways within the RSC to understand how different neuron types influence memory and spatial awareness,” Xu added. “Our aim is to create a comprehensive map of the brain’s ‘GPS system.’ This will enhance our comprehension of how we navigate our environment and form memories, as well as help identify specific brain cells and pathways involved in disorders such as Alzheimer’s, leading to targeted therapies.”
Additional researchers involved in this project include Xiaoxiao Lin, Ali Ghafuri, Xiaojun Chen, and Musab Kazmi, all associated with Xu’s lab, along with co-corresponding author Douglas A. Nitz, professor and chair of cognitive science at UC San Diego.
This research received support from the National Institutes of Health through grants NS078434, MH120020, and U01AG076791.
