Hippocampal Wdr1 Deficit Impairs Learning and Memory by Perturbing F-actin Depolymerization in Mice

Area of Science:

• Neuroscience
• Molecular Biology
• Cell Biology

Background:

• WD repeat protein 1 (Wdr1) is a conserved eukaryotic protein that acts as a cofactor for actin-depolymerizing factor (ADF)/cofilin.
• Wdr1 plays a critical role in the dynamic reorganization of the actin cytoskeleton.
• The specific function of Wdr1 within the central nervous system, particularly in relation to cognitive functions, remained largely unknown.

Purpose of the Study:

• To investigate the role of Wdr1 in the central nervous system, focusing on its involvement in synaptic plasticity and memory.
• To elucidate the molecular mechanisms by which Wdr1 influences neuronal function and behavior.

Main Methods:

• Utilized Wdr1 conditional knockout (CKO) mice to study the effects of Wdr1 deficiency in the brain.
• Assessed behavioral phenotypes, including spatial learning and fear responses.
• Examined synaptic structure and function, including spine morphology, long-term potentiation (LTP), and long-term depression (LTD) in hippocampal CA1 neurons.
• Investigated the impact of Wdr1 deficiency on actin rearrangement and ADF/cofilin activity.

Main Results:

• Wdr1 CKO mice displayed significant deficits in reversal spatial learning and altered fear responses.
• Abnormalities in dendritic spine morphology and synaptic function were observed in Wdr1-deficient mice.
• Enhanced hippocampal LTP and impaired LTD were noted in Wdr1 CKO mice.
• Wdr1 deficiency disrupted actin rearrangement by modulating ADF/cofilin activity.

Conclusions:

• Wdr1 in the hippocampal CA1 area is essential for regulating actin dynamics.
• These actin dynamics are critical for associative learning and maintaining postsynaptic receptor availability.
• Wdr1 plays a significant role in synaptic plasticity and memory formation within the central nervous system.