Developmental Neurophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Department of Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
PLoS One. 2013 Dec 20;8(12):e83074. doi: 10.1371/journal.pone.0083074. eCollection 2013.
Due to improved survival rates and outcome of human infants experiencing a hypoxic-ischemic episode, cognitive dysfunctions have become prominent. They might result from abnormal communication within prefrontal-hippocampal networks, as synchrony and directed interactions between the prefrontal cortex and hippocampus account for mnemonic and executive performance. Here, we elucidate the structural and functional impact of hypoxic-ischemic events on developing prefrontal-hippocampal networks in an immature rat model of injury. The magnitude of infarction, cell loss and astrogliosis revealed that an early hypoxic-ischemic episode had either a severe or a mild/moderate outcome. Without affecting the gross morphology, hypoxia-ischemia with mild/moderate outcome diminished prefrontal neuronal firing and gamma network entrainment. This dysfunction resulted from decreased coupling synchrony within prefrontal-hippocampal networks and disruption of hippocampal theta drive. Thus, early hypoxia-ischemia may alter the functional maturation of neuronal networks involved in cognitive processing by disturbing the communication between the neonatal prefrontal cortex and hippocampus.
由于经历缺氧缺血事件的人类婴儿的存活率和预后得到改善，认知功能障碍变得突出。它们可能是由于前额叶-海马网络内的异常通讯引起的，因为前额叶皮层和海马体之间的同步和定向相互作用是记忆和执行表现的基础。在这里，我们在损伤的未成熟大鼠模型中阐明了缺氧缺血事件对发育中的前额叶-海马网络的结构和功能的影响。梗死、细胞丢失和星形胶质增生的程度表明，早期缺氧缺血事件的结果要么是严重的，要么是轻度/中度的。轻度/中度缺氧缺血没有影响大体形态，却降低了前额叶神经元的放电和γ网络的传入。这种功能障碍是由于前额叶-海马网络内的耦合同步减少以及海马θ驱动的中断所致。因此，早期缺氧缺血可能通过干扰新生儿前额叶皮层和海马体之间的通讯，改变参与认知处理的神经网络的功能成熟。
