Study finds age-related weakening in hippocampus-prefrontal cortex brain circuit in rats
Researchers using advanced neural recording techniques found that the connection between the hippocampus and medial prefrontal cortex weakens with age in rats, particularly affecting the infralimbic region. This circuit is critical for spatial working memory and decision-making functions. The findings may help explain cognitive decline in aging, including reduced cognitive flexibility.
A study published on bioRxiv examined how aging affects the functional connection between the hippocampus and medial prefrontal cortex (mPFC) in rats by recording neural responses in young (10-12 months) and aged (23-26 months) animals. Using high-density Neuropixels probes, researchers stimulated different hippocampal regions and measured resulting activity in the prefrontal cortex. They found that aging selectively impaired both direct synaptic transmission from the ventral hippocampus to the infralimbic cortex and local circuit responses within the mPFC itself. Notably, the infralimbic region showed particular vulnerability to aging effects. The researchers observed that polysynaptic responses—reflecting local circuit recruitment—were diminished in aged rats, with different patterns depending on which hippocampal region was stimulated. These circuit-level deficits may contribute to age-related cognitive impairments, particularly in cognitive flexibility.
Limitations & open questions
The study's own limitations are not detailed in the abstract provided, such as whether findings in male F344 rats generalize to females or other species, the mechanisms underlying the observed synaptic weakening, or whether these circuit changes directly correlate with behavioral cognitive decline in the same animals.
What different sources said
- bioRxivCenter
Hippocampus-evoked polysynaptic responses in the medial prefrontal cortex are attenuated in aged rats.
Related
Fluorescence Correlation Spectroscopy Used to Monitor Chlamydia Protein Production in Cell-Free System
Researchers used fluorescence correlation spectroscopy (FCS) to track the real-time production of a Chlamydia outer protein (CopB) fused with a fluorescent marker in a cell-free protein synthesis system. The technique allowed them to measure protein concentration, size, aggregation, and maturation rates without requiring protein purification. This approach could streamline the characterization of proteins during synthesis for research and biotechnology applications.
DNA Origami Nanoparticles with Oligolysine Coating Show Promise for Retinal Cell Uptake
Researchers found that coating DNA origami nanoparticles with PEG5K-K10, a cationic polymer, significantly improves their uptake into retinoblastoma cells while maintaining safety and mobility in the eye. The coating was essential for cell internalization and did not impair the particles' ability to diffuse through the vitreous humor. These findings suggest DNA origami nanoparticles could be viable carriers for delivering therapeutic agents to treat eye diseases.
Spatial Clustering of Adhesion-Deficient Cells Controls Epithelial Tissue Rigidity, Study Shows
A computational study using vertex modeling demonstrates that how adhesion-deficient cells are spatially arranged in epithelial tissue—not just their number—determines whether the tissue loses mechanical rigidity. Clustered mutant cells cause sustained mechanical changes through sequential boundary removal, while randomly distributed ones are rapidly eliminated with minimal lasting effects. The findings suggest spatial organization is a key factor in early-stage cancer progression and epithelial-mesenchymal transition.