Biophysical Kv3 channel alterations dampen excitability of cortical PV interneurons and contribute to network hyperexcitability in early Alzheimer's
Abstract
In Alzheimer's disease (AD), a multitude of genetic risk factors and early biomarkers are known. Nevertheless, the causal factors responsible for initiating cognitive decline in AD remain controversial. Toxic plaques and tangles correlate with progressive neuropathology, yet disruptions in circuit activity emerge before their deposition in AD models and patients. Parvalbumin (PV) interneurons are potential candidates for dysregulating cortical excitability, as they display altered AP firing before neighboring excitatory neurons in prodromal AD. Here we report a novel mechanism responsible for PV hypoexcitability in young adult familial AD mice. We found that biophysical modulation of Kv3 channels, but not changes in their mRNA or protein expression, were responsible for dampened excitability in young 5xFAD mice. These K+ conductances could efficiently regulate near-threshold AP firing, resulting in gamma-frequency specific network hyperexcitability. Thus biophysical ion channel alterations alone may reshape cortical network activity prior to changes in their expression levels. Our findings demonstrate an opportunity to design a novel class of targeted therapies to ameliorate cortical circuit hyperexcitability in early AD.
Data availability
We share access to our original code for simulations (single cell, reduced single cell in network, and layer 5 cortical network used in this manuscript for reviewers and the public here: https://github.com/ViktorJOlah/KDR-in-FS-PV. This code dataset has been made publicly available here: https://doi.org/10.5061/dryad.08kprr557For Mass Spec data, full source data has been provided for Supplementary Figure 4 (Related to Main figure 4).
-
Biophysical Kv channel alterations dampen excitability of cortical PV interneurons and contribute to network hyperexcitability in early Alzheimer'sDryad Digital Repository, doi:10.5061/dryad.08kprr557.
Article and author information
Author details
Funding
National Institutes of Health (R56AG072473)
- Matthew JM Rowan
National Institutes of Health (RF1AG062181)
- Nicholas T Seyfried
National Institutes of Health (F32AG064862)
- Sruti Rayaprolu
National Institutes of Health (R01MH111529)
- Jordane Dimidschstein
National Institutes of Health (UG3MH120096)
- Jordane Dimidschstein
Alzheimer's Disease Research Center, Emory University (00100569)
- Matthew JM Rowan
National Institutes of Health (R01NS114130)
- Srikant Rangaraju
National Institutes of Health (R01AG075820)
- Srikant Rangaraju
National Institutes of Health (RF1AG071587)
- Srikant Rangaraju
National Institutes of Health (RF1AG071587)
- Nicholas T Seyfried
National Institutes of Health (R01AG061800)
- Nicholas T Seyfried
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All of the animals were handled according to approved Emory University institutional animal care and use committee (IACUC) protocols (#201800199). Every effort was made to reduce animal useage and to minimize suffering.
Copyright
© 2022, Olah et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 1,781
- views
-
- 449
- downloads
-
- 21
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Neuroscience
People selectively help others based on perceptions of their merit or need. Here, we develop a neurocomputational account of how these social perceptions translate into social choice. Using a novel fMRI social perception task, we show that both merit and need perceptions recruited the brain’s social inference network. A behavioral computational model identified two non-exclusive mechanisms underlying variance in social perceptions: a consistent tendency to perceive others as meritorious/needy (bias) and a propensity to sample and integrate normative evidence distinguishing high from low merit/need in other people (sensitivity). Variance in people’s merit (but not need) bias and sensitivity independently predicted distinct aspects of altruism in a social choice task completed months later. An individual’s merit bias predicted context-independent variance in people’s overall other-regard during altruistic choice, biasing people toward prosocial actions. An individual’s merit sensitivity predicted context-sensitive discrimination in generosity toward high and low merit recipients by influencing other- and self-regard during altruistic decision-making. This context-sensitive perception–action link was associated with activation in the right temporoparietal junction. Together, these findings point toward stable, biologically based individual differences in perceptual processes related to abstract social concepts like merit, and suggest that these differences may have important behavioral implications for an individual’s tendency toward favoritism or discrimination in social settings.
-
- Neuroscience
Mice lacking two neuropeptides thought to be essential for processing pain show no change in how they respond to a wide range of harmful stimuli.