Using electrocorticogram (ECoG) analysis, we compared age-related dynamics of general neuronal activity and convulsive epileptiform responsiveness induced by intracortical microinjections of 4-aminopyridine (4-AP) in control Wistar rats and those subjected to prenatal hypoxia (Hx; E14; 7% O2, 3 h). The studies were carried out in three age periods roughly corresponding to childhood (P20-27), adolescence (P30-45), and adulthood (P90-120). It was found that in the process of postnatal development of the control rats, the peak of the ECoG power spectrum density (PSD) of the theta rhythm during wakefulness shifted from the low to the higher frequency, while in the Hx rats this shift had the opposite direction. Moreover, the Hx rats had different frequency characteristics of the ECoG PSD and longer episodes of spike-and-wave discharges caused by 4-AP injections compared to the controls. The total ECoG PSD of slow-wave sleep (1-5 Hz) was also dramatically decreased in the process of development of the Hx rats. Such alterations in PSD could be explained by the changes in balance of the excitation and inhibition processes in the cortical networks. Analyzing protein levels of neurotransmitter transporters in the brain structures of the Hx rats, we found that the content of the glutamate transporter EAAT1 was higher in the parietal cortex in all age groups of Hx rats while in the hippocampus it decreased during postnatal development compared to controls. Furthermore, the content of the vesicular acetylcholine transporter in the parietal cortex, and of the inhibitory GABA transporter 1 in the hippocampus, was also affected by prenatal Hx. These data suggest that prenatal Hx results in a shift in the excitatory and inhibitory balance in the rat cortex towards excitation, making the rat's brain more vulnerable to the effects of proconvulsant drugs and predisposing animals to epileptogenesis during postnatal life.

中文翻译：

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产前缺氧大鼠的年龄依赖性脑电图动力学和癫痫反应性。

使用脑电图（ECoG）分析，我们比较了对照Wistar大鼠和遭受产前低氧（Hx; E14; 7）的大鼠皮层内注射4-氨基吡啶（4-AP）诱导的一般神经元活动和惊厥性癫痫样反应的年龄相关动力学。 ％O2，3 h）。该研究在三个年龄段进行，大致对应于儿童期（P20-27），青春期（P30-45）和成年期（P90-120）。发现在对照组大鼠的产后发育过程中，清醒时θ节律的ECoG功率谱密度（PSD）的峰值从低频移到了较高频率，而在Hx大鼠中，这种偏移具有相反的方向。此外，与对照组相比，Hx大鼠的ECoG PSD的频率特征不同，并且由4-AP注射引起的尖峰和波放电的发作时间更长。在Hx大鼠的发育过程中，慢波睡眠（1-5 Hz）的总ECoG PSD也显着降低。PSD的这种变化可以用皮质网络中激发和抑制过程的平衡变化来解释。分析Hx大鼠脑结构中神经递质转运蛋白的蛋白水平，我们发现，Hx大鼠所有年龄组的顶叶皮层中谷氨酸转运蛋白EAAT1的含量均较高，而海马中谷氨酸转运蛋白EAAT1的含量在出生后发育过程中比对照组下降。此外，顶叶皮层中水泡乙酰胆碱转运蛋白的含量 和海马中的抑制性GABA转运蛋白1也受到产前Hx的影响。这些数据表明，产前Hx导致大鼠皮层的兴奋性和抑制性平衡朝着兴奋的方向转移，使大鼠的大脑更容易受到惊厥药的影响，并使动物在出生后的生命中容易发生癫痫。