Altered brain development in fetal and neonatal piglets following maternal porcine respiratory and reproductive syndrome virus (PRRSV) infection

Abstract

Maternal infection during pregnancy is a risk factor for neurological disorders in children. To study the effect of infection in a species with brain development similar to humans, pregnant sows were given saline or PRRSV intranasal at gestational day (GD) 77. PRRSV+ sows were febrile and anorectic for 2 wks. On GD112, 45 control fetuses and 31 fetuses from PRRSV sows were obtained by c-section and PRRSV status was determined by RT-PCR. Control fetuses were PRRSV−, 10 fetuses from PRRSV sows were PRRSV+ and 21 were PRRSV−. PRRSV+ fetuses had decreased brain weight ( p . 004 ) compared to controls. Hippocampal tissue from PRRSV−/+ fetuses revealed a decrease in neurons in the subiculum and dentate gyrus ( p 0.001 ) compared to controls. Increased GFAP staining was observed in the hilar region ( p . 04 ) of PRRSV− fetuses. To assess postnatal brain development following maternal infection, 29 control piglets and 27 piglets from PRRSV sows were artificially reared until postnatal day (PD) 28. Twenty-one piglets from PRRSV sows were PRRSV+ and 6 were PRRSV−. The PRRSV+ piglets were febrile and anorectic PD7 to PD14 ( p . 001 ); and had reduced body weight and brain weight at PD28. PRRSV+/− piglets from PRRSV sows had increased Ki-67+ cells in the hilar region ( p . 03 ) compared to controls. Thus maternal infection may affect neural development in piglets, reducing the number of hippocampal neurons and increasing the number of glia.