Biology subjects

He, J. S.

Publications and source records attributed to He, J. S..

2 recordsLinked to original sources

bioRxiv2025

Stable neuronal representations to repeated stimulation underlie cognitive resilience in Alzheimer's disease pathology

While Alzheimers Disease (AD) typically triggers cognitive decline, some individuals with significant AD pathology maintain normal cognition into late life. Understanding the neuronal underpinnings of such cognitive resilience would propel the development of interventions for delaying dementia. To this end, we used cognitive testing to identify a subset of cognitively resilient 13-month-old TgF344-AD rats (established AD) and their non-transgenic littermates, followed by Neuropixels recording from 8500 neurons during repeated somatosensory stimulation. Cognitively resilient TgF344-AD rats recruited fewer neurons yet displayed more stable neuronal representations during repeated stimulations in cortical excitatory and hippocampal inhibitory ensembles, with reduced excitatory spike burstiness during network activation and a distinct pattern of functional synaptic connectivity. These associations existed independently of amyloid and tau levels. For the first time, our study revealed neuronal population-level hallmarks of maintained cognition that may serve as a novel neurophysiological biomarker of cognitive resilience and a target for stabilizing cognition.

neuroscience↗

bioRxiv2024

Variable responses of alpine-plant communities to warming and loss of dominant species

Responses of ecological communities to perturbations are inherently variable because responses of their constituent populations also vary. Species within a single community may show combinations of no response, positive responses, and negative responses to any given perturbation often canceling each other out resulting in small or no signal that the community level. Here we explore the impacts of warming and loss of the dominant species on alpine ecosystems in a global study. We investigate warming and species-loss treatments on population- and community-level dynamics across alpine-plant communities at two elevations in five globally-distributed mountain locations. Communities showed varied responses to treatments; no community showed strong responses to a single treatment. Rather, most sites were influenced by both perturbations. Populations within these communities responded idiosyncratically, suggesting that constituent species are not all equally robust to perturbations even when community-level effects appear weak. Our results highlight the challenge of making general predictions about population- and community-level responses of alpine ecosystems in the face of present and future perturbations.

ecology↗