Postnatal high-protein diet improves learning and memory in premature rats via activation of mTOR signaling

Area of Science:

• Neuroscience
• Developmental Biology
• Nutritional Science

Background:

• Premature birth can lead to cognitive deficits, including impaired spatial learning and memory.
• Mammalian target of rapamycin (mTOR) signaling plays a crucial role in neuronal development and synaptic plasticity.
• Dietary interventions are being explored to mitigate developmental impairments.

Purpose of the Study:

• To investigate the effect of a high-protein diet (HPD) on spatial learning and memory in premature rats.
• To determine if HPD modulates the mammalian target of rapamycin (mTOR) signaling pathway in the hippocampus.
• To assess the potential of HPD to restore cognitive deficits associated with prematurity.

Main Methods:

• Premature and full-term Sprague-Dawley rat pups were fed either a normal (18% protein) or HPD (30% protein) for 6 or 8 weeks post-weaning.
• Spatial learning and memory were evaluated using the Morris water maze test.
• Hippocampal mTOR signaling pathway components (p70S6K and 4EBP1 phosphorylation) were analyzed via western blotting.

Main Results:

• Premature rats exhibited lower spatial memory than full-term rats at 6 weeks, correlating with reduced hippocampal p70S6K and 4EBP1 phosphorylation.
• Spatial memory significantly improved in premature rats fed an HPD for 8 weeks compared to those on a normal diet.
• HPD consumption normalized hippocampal p70S6K and 4EBP1 phosphorylation levels in premature rats to levels seen in full-term rats on an HPD.

Conclusions:

• Long-term HPD consumption can ameliorate spatial learning and memory impairments in pre-term rats.
• The restorative effects are mediated through the upregulation of the mTOR/p70S6K signaling pathway in the hippocampus.
• Dietary protein intake is a potential therapeutic strategy for cognitive deficits in premature offspring.