||Hiroyoshi Doi, Taito Matsuda, Atsuhiko Sakai, Shuzo Matsubara, Sumio Hoka, Ken Yamaura, Kinichi Nakashima, Early-life midazolam exposure persistently changes chromatin accessibility to impair adult hippocampal neurogenesis and cognition., Proceedings of the National Academy of Sciences of the United States of America, 10.1073/pnas.2107596118, 118, 38, 2021.09, Linkage between early-life exposure to anesthesia and subsequent learning disabilities is of great concern to children and their families. Here we show that early-life exposure to midazolam (MDZ), a widely used drug in pediatric anesthesia, persistently alters chromatin accessibility and the expression of quiescence-associated genes in neural stem cells (NSCs) in the mouse hippocampus. The alterations led to a sustained restriction of NSC proliferation toward adulthood, resulting in a reduction of neurogenesis that was associated with the impairment of hippocampal-dependent memory functions. Moreover, we found that voluntary exercise restored hippocampal neurogenesis, normalized the MDZ-perturbed transcriptome, and ameliorated cognitive ability in MDZ-exposed mice. Our findings thus explain how pediatric anesthesia provokes long-term adverse effects on brain function and provide a possible therapeutic strategy for countering them..
||Atsuhiko Sakai, Taito Matsuda, Hiroyoshi Doi, Yukiko Nagaishi, Kiyoko Kato, Kinichi Nakashima, Ectopic neurogenesis induced by prenatal antiepileptic drug exposure augments seizure susceptibility in adult mice., Proceedings of the National Academy of Sciences of the United States of America, 10.1073/pnas.1716479115, 115, 16, 4270-4275, 2018.04, Epilepsy is a neurological disorder often associated with seizure that affects ∼0.7% of pregnant women. During pregnancy, most epileptic patients are prescribed antiepileptic drugs (AEDs) such as valproic acid (VPA) to control seizure activity. Here, we show that prenatal exposure to VPA in mice increases seizure susceptibility in adult offspring through mislocalization of newborn neurons in the hippocampus. We confirmed that neurons newly generated from neural stem/progenitor cells (NS/PCs) are integrated into the granular cell layer in the adult hippocampus; however, prenatal VPA treatment altered the expression in NS/PCs of genes associated with cell migration, including CXC motif chemokine receptor 4 (Cxcr4), consequently increasing the ectopic localization of newborn neurons in the hilus. We also found that voluntary exercise in a running wheel suppressed this ectopic neurogenesis and countered the enhanced seizure susceptibility caused by prenatal VPA exposure, probably by normalizing the VPA-disrupted expression of multiple genes including Cxcr4 in adult NS/PCs. Replenishing Cxcr4 expression alone in NS/PCs was sufficient to overcome the aberrant migration of newborn neurons and increased seizure susceptibility in VPA-exposed mice. Thus, prenatal exposure to an AED, VPA, has a long-term effect on the behavior of NS/PCs in offspring, but this effect can be counteracted by a simple physical activity. Our findings offer a step to developing strategies for managing detrimental effects in offspring exposed to VPA in utero..