Perinatal Protein Restriction Induces Anhedonic-Like Behavior: Disturbed Hippocampal Neurotrophic Signaling and...

Area of Science:

• Neuroscience
• Developmental Biology
• Nutritional Psychiatry

Background:

• Early life nutrition significantly impacts brain development and function.
• Protein malnutrition during critical developmental periods can lead to lasting neurobiological changes.
• Anhedonia, a core symptom of depression, is associated with alterations in the brain's reward circuitry.

Purpose of the Study:

• To investigate the effects of maternal protein restriction on anhedonia in adult rats.
• To examine the role of hippocampal brain-derived neurotrophic factor (BDNF)-TrkB signaling in protein-restriction-induced anhedonia.
• To assess structural plasticity changes in the CA1 subregion of the dorsal hippocampus.

Main Methods:

• Adult rats exposed to protein restriction from gestation to postnatal day 30 (PR-rats) were compared to control rats.
• Sucrose preference test (SPT) was used to measure anhedonia.
• Levels of BDNF, phosphorylated TrkB (p-TrkB), and dendritic spine density in the dorsal hippocampus (DH) CA1 region were assessed.

Main Results:

• PR-rats exhibited significantly reduced sucrose preference, indicating anhedonia.
• Anhedonia in PR-rats correlated with decreased BDNF and p-TrkB levels in the DH.
• Reduced dendritic spine density, particularly mature spines (stubby and mushroom), was observed in CA1 pyramidal neurons of PR-rats.

Conclusions:

• Perinatal protein restriction contributes to anhedonia by impairing hippocampal BDNF-TrkB signaling.
• Structural remodeling, including reduced dendritic spine density in the CA1 region, may underlie the anhedonic phenotype.
• These findings highlight the long-term vulnerability to anhedonia resulting from early-life nutritional deficits.