Maternal diet during early gestation influences postnatal taste activity-dependent pruning by microglia

Area of Science:

• Neuroscience
• Developmental Biology
• Immunology

Background:

• Central sensory circuit development relies on activity-dependent pruning of neural connections.
• The nucleus of the solitary tract (NST) processes gustatory information and undergoes significant maturation postnatally.

Purpose of the Study:

• To investigate the role of maternal diet and myeloid cells in gustatory terminal field pruning in the developing mouse brain.
• To understand the timing and mechanisms underlying activity-dependent pruning in the gustatory system.

Main Methods:

• Studied gustatory terminal field maturation in postnatal mice under normal conditions and following maternal low NaCl diet.
• Assessed pruning by examining complement system involvement and taste activity.
• Investigated the role of myeloid cells by activating or inhibiting their function.

Main Results:

• Normal pruning of gustatory terminals involves the complement system and NaCl-elicited taste activity.
• Maternal low NaCl diet during a critical embryonic period impaired gustatory terminal pruning.
• Pruning deficits were rescued by postnatal myeloid cell activation and exacerbated by myeloid cell dysfunction.
• Altered pruning and myeloid cell function appear programmed early, linked to embryonic microglia colonization.

Conclusions:

• Early life nutritional environment critically influences sensory circuit development and pruning.
• Myeloid cells, particularly microglia, play a vital role in activity-dependent synaptic pruning.
• The timing of these events suggests prenatal programming of postnatal circuit refinement.