Synaptotagmin and synaptic transmission alterations in apolipoprotein E-deficient mice

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Apolipoprotein E (apoE) plays a role in lipid transport and neuronal repair.
• Dysregulation of apoE is implicated in cognitive decline and neurodegenerative diseases.
• Synaptic dysfunction is a hallmark of impaired cognitive function.

Purpose of the Study:

• To investigate the cognitive performance of aged apolipoprotein E-deficient mice.
• To explore the relationship between cognitive deficits, electrophysiological changes, and synaptic protein expression in these mice.
• To elucidate the role of apolipoprotein E in synaptic function and neurotransmission.

Main Methods:

• Cognitive function was assessed using the Morris water maze in aged apoE-deficient mice and controls.
• In vivo electrophysiology was performed to measure neuronal activity in the dentate gyrus.
• Expression levels of the synaptic protein synaptotagmin (p65) were analyzed.

Main Results:

• ApoE-deficient mice exhibited significant cognitive impairments compared to age-matched controls.
• In vivo electrophysiological alterations were observed in the dentate gyrus of apoE-deficient mice.
• A significant increase in synaptotagmin expression, a key calcium sensor, was found in apoE-deficient mice.

Conclusions:

• Cognitive impairments in apoE-deficient mice are associated with reduced synaptic excitability in hippocampal neurons.
• Apolipoprotein E may regulate synaptic function through modulation of calcium sensor protein expression.
• These findings highlight the critical role of apoE in maintaining synaptic integrity and cognitive health.