Kim Eun Jung, Nip Kaila, Blanco Cynthia, Kim Jun Hee
Department of Cellular and Integrative Physiology, University of Texas Health Science Center, San Antonio, TX, United States.
Department of Pediatrics, University of Texas Health Science Center, San Antonio, TX, United States.
Front Cell Neurosci. 2021 Apr 9;15:648562. doi: 10.3389/fncel.2021.648562. eCollection 2021.
Children born prematurely suffer from learning disabilities and exhibit reading, speech, and cognitive difficulties, which are associated with an auditory processing disorder. However, it is unknown whether gestational age at delivery and the unnatural auditory environment in neonatal intensive care units (NICU) collectively affect proper auditory development and neuronal circuitry in premature newborns. We morphologically characterized fetal development of the medial superior olivary nucleus (MSO), an area important for binaural hearing and sound localization, in the auditory brainstem of baboon neonates at different gestational ages. Axonal and synaptic structures and the tonotopic differentiation of ion channels in the MSO underwent profound refinements after hearing onset in the uterus. These developmental refinements of the MSO were significantly altered in preterm baboon neonates in the NICU. Thus, the maternal environment in uterus is critical for auditory nervous system development during the last trimester of pregnancy and critically affects the anatomic and functional formation of synapses and neural circuitry in the preterm newborn brain.
早产儿存在学习障碍，表现出阅读、言语和认知困难，这些与听觉处理障碍有关。然而，分娩时的胎龄和新生儿重症监护病房（NICU）中不自然的听觉环境是否共同影响早产儿正常的听觉发育和神经回路尚不清楚。我们对不同胎龄狒狒新生儿听觉脑干中内侧上橄榄核（MSO）的胎儿发育进行了形态学特征分析，MSO是对双耳听觉和声音定位很重要的区域。在子宫内开始听觉后，MSO中的轴突和突触结构以及离子通道的音调拓扑分化经历了深刻的细化。NICU中早产狒狒新生儿的MSO这些发育细化发生了显著改变。因此，子宫内的母体环境对于妊娠晚期听觉神经系统的发育至关重要，并严重影响早产儿大脑中突触和神经回路的解剖和功能形成。
