Prenatal Exposure to Alcohol Alters TLR4 Mediated Signaling in the Prefrontal Cortex in Rats

Prenatal alcohol exposure (PAE) can lead to developmental disorders of the central nervous system (CNS) and mental retardation. Toll-like receptor (TLR) 4 plays an important role in the development of defects in the nervous system caused by PAE. However, how PAE affects the TLR4 response in the brain remains unclear. Using the model of semi-forced alcoholization of pregnant rats, we have investigated TLR4-mediated signaling on the 30th day of postnatal development in their offspring. Rats exposed to PAE showed a higher expression of proinflammatory cytokines in the prefrontal cortex, but TLR4-mediated signaling in response to lipopolysaccharide (LPS) was weakened. These data suggest that PAE can lead to neuroinflammation and suppression of the TLR4-mediated response to LPS in the prefrontal cortex of young rats. Since innate immunity plays an important role in brain development, PAE-induced suppression of the TLR4-mediated response may be one of the mechanisms for the development of CNS pathology.