The Impact of Early Growth Response 1 (Egr1) on Hippocampal Synaptic Plasticity and Cognitive Function: Narrative Review

Abstract

Introduction: EGR1 (Early Growth Response 1) gene expression is a molecular response that occurs in the brain as a result of synaptic activity and environmental stimuli. Early growth response 1 (EGR1) expression can be affected by several factors, including exercise or physical training. This review aims to determine the effect of EGR 1 expression on hippocampal synaptic plasticity function. Method: Literature search using data-based Pubmed, Science Direct, and Scopus online. The data used is from the year 1978 until the year 2022. Searched using English keywords such as EGR 1 and hippocampus. Results: Animal and human studies show that physical exercise can increase the expression of the EGR1 gene in the brain. This enhanced EGR1 expression is associated with increased synaptic plasticity, which includes changes in the strength and connectivity of synapses between neurons. Synaptic plasticity refers to the ability of the nervous system to change the strength and efficiency of communication between neurons. Physical exercise has been shown to increase synaptic plasticity by increasing dendritic growth and continuity, increasing neurogenesis (the formation of new neurons), and increasing synaptic connections between neurons. Physical exercise can increase EGR1 expression and synaptic plasticity. Increased EGR1 expression and synaptic plasticity induced by physical exercise are associated with improvements in cognitive functions, including memory, learning, and thinking ability. Conclusion: There is evidence that exercise can increase EGR1 expression and synaptic plasticity in the brain, especially in the hippocampus, to improve cognitive function.