Limbic system synaptic dysfunctions associated with prion disease onset
- PMID: 39707496
- PMCID: PMC11662616
- DOI: 10.1186/s40478-024-01905-w
Limbic system synaptic dysfunctions associated with prion disease onset
Abstract
Misfolding of normal prion protein (PrPC) to pathological isoforms (prions) causes prion diseases (PrDs) with clinical manifestations including cognitive decline and mood-related behavioral changes. Cognition and mood are linked to the neurophysiology of the limbic system. Little is known about how the disease affects the synaptic activity in brain parts associated with this system. We hypothesize that the dysfunction of synaptic transmission in the limbic regions correlates with the onset of reduced cognition and behavioral deficits. Here, we studied how prion infection in mice disrupts the synaptic function in three limbic regions, the hippocampus, hypothalamus, and amygdala, at a pre-clinical stage (mid-incubation period) and early clinical onset. PrD caused calcium flux dysregulation associated with lesser spontaneous synchronous neuronal firing and slowing neural oscillation at the pre-clinical stage in the hippocampal CA1, ventral medial hypothalamus, and basolateral amygdala (BLA). At clinical onset, synaptic transmission and synaptic plasticity became significantly disrupted. This correlated with a substantial depletion of the soluble prion protein, loss of total synapses, abnormal neurotransmitter levels and synaptic release, decline in synaptic vesicle recycling, and cytoskeletal damage. Further, the amygdala exhibited distinct disease-related changes in synaptic morphology and physiology compared with the other regions, but generally to a lesser degree, demonstrating how different rates of damage in the limbic system influence the evolution of clinical disease. Overall, PrD causes synaptic damage in three essential limbic regions starting at a preclinical stage and resulting in synaptic plasticity dysfunction correlated with early disease signs. Therapeutic drugs that alleviate these early neuronal dysfunctions may significantly delay clinical onset.
Keywords: Cognition; Emotion; Limbic system; Neurodegeneration; Prion disease; Synaptic transmission.
© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.
Conflict of interest statement
Declarations. Ethics approval and consent to participate: All animal experiments were approved by the Rocky Mountain Laboratories Animal Care and Use Committee under protocols 2019-043 and 2022–045. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests.
Figures






References
-
- Mallucci GR et al (2007) Targeting cellular prion protein reverses early cognitive deficits and neurophysiological dysfunction in prion-infected mice. Neuron 53(3):325–335 - PubMed
-
- Senesi M et al (2023) Tailored behavioural tests reveal early and progressive cognitive deficits in M1000 prion disease. Neurobiol Dis 180:106075 - PubMed
-
- Guenther K et al (2001) Early behavioural changes in scrapie-affected mice and the influence of dapsone. Eur J Neurosci 14(2):401–409 - PubMed
Publication types
MeSH terms
LinkOut - more resources
Full Text Sources
Research Materials
Miscellaneous