Summary: According to research, the retrosplenial cortex ( RSC ) contains two neural circuits that are essential for memory storage and spatial navigation. The M2-projecting road links geographical thought to activity, while the AD-projecting route supports location-specific memory.
Using sophisticated tracking techniques, the group found that inhibiting these wires impaired object-location storage and spatial activities. These findings provide a framework for better understanding of how certain brain regions are affected by neurodegenerative diseases like Alzheimer’s, which could lead to more precise treatments.
Important Facts:
- Two RSC pathways were identified: M2-projecting ( action ) and AD-projecting ( memory ).
- Blocking M2 cells impaired spatial steps, while Advertising cells affected memory understand.
- Perspectives into RSC circuits does guide remedies for Alzheimer’s and mental disorders.
Origin: UC Irvine
The University of California, Irvine experts are the first to demonstrate that geographical transportation and storage store are directly related to two neural circuits in the body’s retrosplenial brain.
By enabling pathway-specific neurological circuits, this discovery could enable more accurate clinical treatments for Alzheimer’s disease and various mental disorders.
The study, just published online in the journal , Molecular Psychiatry, identified two kinds of RSC processes, connected to different parts of the brain, each with its own style of input and features.
Our results provide an anatomical basis for future research and provide new insights about how we learn and remember the place around us, according to guide and co-corresponding artist Xiangmin Xu, UC Irvine Chancellor’s Professor of biology and neurology and director of the school’s Center for Neural Circuit Mapping.
This will help us develop novel treatments and approaches to better understand how conditions like Alzheimer’s disease and other neurodegenerative disorders affect particular brain regions.
Multiple brain regions are connected to the RSC. The team focused on two main pathways, the M2-projecting, which is connected to the secondary motor cortex, and the AD-projecting, which is connected to the anterior thalamus.
The AD neurons are crucial for remembering specific locations, while the M2 neurons are responsible for translating spatial thought into action.
Researchers used sophisticated viral tools to separately map and manipulate the connections and assess the effects in order to observe these circuits in action.
They discovered that it became more difficult to remember where objects were located and how to associate specific locations with actions when M2-projecting neurons were blocked. AD-projecting neurons were only affected by reducing memory of location-related objects.
We are expanding on these findings, looking at how various neuronal types affect memory and spatial orientation, according to Xu.
” Our goal is to build a map of the brain’s ‘ GPS system.’ This will help us identify specific brain cells and their pathways that contribute to various disorders like Alzheimer’s disease and develop treatments that target them in addition to expanding our understanding of how we navigate our world and creating memories of it.
Other team members were Xiaoxiao Lin, Ali Ghafuri, Xiaojun Chen and Musab Kazmi, all current or former members of Xu’s lab, and co-corresponding author Douglas A. Nitz, professor and chair of cognitive science at UC San Diego.
Funding: This work was supported by the National Institutes of Health under grants NS078434, MH120020 and U01AG076791.
About this news from neuroscience research
Author: Patricia Harriman
Source: UC Irvine
Contact: Patricia Harriman – UC Irvine
Image: The image is credited to Neuroscience News
Original Research: Open access.
” Differential contributions to spatial cognition are made by projection-specific retrosplenial cortex circuits.” by Xiangmin Xu et al. Molecular Psychiatry
Abstract
Differential contributions to spatial cognition are made by projection-specific retrosplenial cortex circuits.
Neuropsychiatric and neurodegenerative disorders involve the brain region known as the retrosplenium cortex ( RSC ). Although it has reciprocal connections with a number of cortical and subcortical brain regions, its afferent structure and behavioral function are still a mystery.
It has been suggested that RSC and secondary motor cortex ( M2 ) have semi-independent but parallel connections to each other that affect spatial information processing.
We compared and quantitatively characterize the afferent and efferent distributions of retrosplenial neuron subpopulations projecting to M2 and AD using retrograde and anterograde viral tracers and monosynaptic retrograde rabies virus. AD-projecting and M2-projecting RSC neurons overlap in their collateral projections to other brain regions, but not in their projections to M2 and AD, respectively.
Compared with AD-projecting RSC neurons, M2-projecting RSC neurons received much greater afferent input from the dorsal subiculum, AD, lateral dorsal and lateral posterior thalamus, and somatosensory cortex. The medial septum and the anterior cingulate cortex both provided more input for AD-projecting RSC neurons.
We performed chemogenetic inhibition of M2- and AD-projecting RSC neurons and examined its impact on object-location memory, object-recognition, open-field exploration, and place-action association.
Our findings show that the RSC to AD pathway’s inhibition of M2-projecting RSC neurons only affects object-location memory while M2-projecting RSC neurons inhibit object location memory and place-action association.
The results reveal that RSC is made up of semi-independent circuits that are distinct in terms of their afferent/efferent distributions and cognitive functions that contribute to them.
