Overactive Neuronal eEF2K/eEF2 signaling is associated with cognitive impairment and apathy-like behavior

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Dysregulated protein synthesis is linked to neurodevelopmental, neurodegenerative, and neuropsychiatric diseases.
• eukaryotic elongation factor 2 (eEF2) phosphorylation by eEF2K regulates protein synthesis and is implicated in cognitive function and ketamine's antidepressant effects.

Purpose of the Study:

• To investigate the causal relationship between overactive eEF2K/eEF2 signaling and impaired synaptic and cognitive function.
• To generate and analyze a transgenic mouse model (eEF2K-cKI) overexpressing eEF2K in excitatory neurons.

Main Methods:

• Assessment of hippocampal-dependent learning and memory in eEF2K-cKI mice.
• Evaluation of neuropsychiatric behaviors including despair, anhedonia, apathy, anxiety, and sociability.
• Analysis of long-term potentiation, dendritic spine morphology, synaptic structure, and proteomic changes.

Main Results:

• eEF2K-cKI mice displayed significant learning and memory impairments.
• A robust apathy-like phenotype was observed, without other depression-like behaviors.
• Impaired long-term potentiation, altered hippocampal synaptic morphology, and changes in neuropsychiatric disorder-associated proteins were identified.

Conclusions:

• Aberrant eEF2K/eEF2 signaling plays a pathophysiological role in brain function.
• Findings provide insights into mechanisms underlying dementia and neuropsychiatric symptoms.
• This study suggests novel therapeutic avenues for neuronal diseases involving cognitive and mood impairments.