Biology subjects

Ibaceta-Gonzalez, C.

Publications and source records attributed to Ibaceta-Gonzalez, C..

2 recordsLinked to original sources

bioRxiv2025

Cognitive Resilience in Aging Degus is Linked to CA3 Hippocampal GABAergic Integrity

The preservation of cognitive function during aging remains a key challenge in neuroscience. In this study, we applied an integrative approach, combining behavioral assays with neurophysiological recordings, to investigate hippocampal circuit integrity. We used Octodon degus, a rodent with exceptional longevity (up to 10 years in laboratory conditions), as a natural model of aging and neurodegenerative disease such as Alzheimer. To assess agerelated cognitive changes, we employed three behavioral tasks: Novel Object Recognition (NOR), Open Field (OF), and the Burrowing Test (BT). The BT reflects Activities of Daily Living (ADLs) and is based on species-typical spontaneous burrowing behavior, which has been linked to neurodegenerative markers in degus. We also performed multielectrode electro-physiological recordings to assess GABAergic function in the hippocampus. Aged degus with high BT performance (classified as good burrowers, or GB) showed robust hippocampal activity, especially in the CA3 region, a key hub for signal integration and memory encoding. In contrast, degus with poor BT performance (bad burrowers, or BB) exhibited reduced spontaneous hippocampal activity, suggesting potential compensation via GABA-independent synaptic mechanisms. Altogether, our findings suggest that preserved GABAergic function supports cognitive resilience in aging degus. These results offer new insights into the neural mechanisms underlying healthy cognitive aging and may inform future strategies for preventing or mitigating neurodegeneration.

neuroscience↗

bioRxiv2024

Prefrontal gamma oscillations and fear extinction learning require early postnatal interneuron-oligodendroglia communication

Emerging evidence links oligodendrocyte (OL) lineage cells and myelin to cognitive processes, yet the role of myelination in shaping neuronal networks critical for cognitive tasks remains unknown. We demonstrate in mice that early postnatal GABAergic signaling between interneurons and oligodendrocyte precursor cells (OPCs) is crucial for myelination of parvalbumin (PV) interneurons, which facilitates in vivo low-gamma oscillations in the medial prefrontal cortex (mPFC) and supports fear extinction learning. Disruption of this signaling results in PV interneuron dysmyelination, decreases low-gamma power, and impairs tone fear extinction. These deficits are specific to PV interneuron dysmyelination, as mPFC myelination, high-gamma oscillations and contextual fear extinction are not significantly altered. Increasing PV interneuron activity or enhancing myelination do not reverse the deficits, indicating the long-term consequences of these early myelination impairments. Our findings reveal the role of OPC GABAergic signaling in PV interneuron myelination and mPFC circuit maturation, with lasting impacts on gamma rhythms and cognition. Brief SummaryEarly postnatal interneuron-oligodendroglia communication may shape neuronal networks underlying cognition. Here, the authors show that disrupting this signaling in mice impairs interneuron myelination, gamma rhythms, and fear-related learning.

neuroscience↗