Running induces widespread structural alterations in the hippocampus and entorhinal cortex

Area of Science:

• Neuroscience
• Neurobiology
• Exercise Science

Background:

• Physical activity is known to improve hippocampal function.
• Neuronal structural adaptations to exercise are less understood, particularly outside the dentate gyrus.

Purpose of the Study:

• To investigate the effects of long-term voluntary running on neuronal structure in the hippocampus and entorhinal cortex.
• To determine if exercise influences dendritic spine density and morphology.

Main Methods:

• Adult rats underwent long-term voluntary running.
• Golgi impregnation and DiI lipophilic tracer were used to visualize neuronal structures.
• Dendritic spine density, arborization, and morphology were analyzed in specific hippocampal and entorhinal cortex regions.

Main Results:

• Voluntary running increased dendritic spine density in the dentate gyrus granule neurons, CA1 pyramidal neurons, and layer III entorhinal cortex pyramidal neurons.
• CA1 pyramidal neurons exhibited changes in dendritic arborization and spine morphology.
• These structural modifications were observed in both the hippocampus and its afferent entorhinal cortex.

Conclusions:

• Physical activity has widespread effects on neuronal morphology within the hippocampus and entorhinal cortex.
• Exercise-induced structural plasticity in these brain regions may underlie improvements in cognitive function.