Rewarded Maze Training Increases Approach Behavior in Rats Through Neurogenesis-Dependent Growth of Ventral...

Area of Science:

• Neuroscience
• Neuroplasticity
• Behavioral Biology

Background:

• Human studies show learning complex routes increases hippocampal volume.
• The cellular mechanisms and broader behavioral impacts of this growth are unclear.

Purpose of the Study:

• To investigate the impact of navigational learning on brain structure and behavior in rats.
• To explore the role of adult neurogenesis and the ventral CA1 (vCA1)-to-prelimbic pathway in these changes.

Main Methods:

• Rats were trained in mazes with or without adult neurogenesis suppression.
• Brain volumes (hippocampus, prelimbic cortex), neuronal/astrocyte morphology, and novelty approach behavior were assessed.
• The vCA1-to-prelimbic pathway's activation and role were examined using immediate-early genes and DREADDs.

Main Results:

• Maze training increased vCA1 and prelimbic cortex volumes and enhanced neuronal/astrocyte growth.
• Trained rats showed increased novelty approach behavior.
• Neurogenesis suppression blocked structural and behavioral changes without affecting maze learning.
• The vCA1-to-prelimbic pathway was more activated in trained rats, and its suppression reduced approach behavior.

Conclusions:

• Rewarded navigation learning drives structural and functional plasticity in the hippocampus and prelimbic cortex.
• Adult neurogenesis is essential for experience-induced structural and behavioral changes, including enhanced novelty exploration.
• The vCA1-to-prelimbic circuit is critical for mediating the behavioral effects of navigational learning.