Astasheva Elena, Astashev Maksim, Kitchigina Valentina
Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow District, Russia.
Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow District, Russia; Institute of Cell Biophysics, Russian Academy of Sciences, Puchshino, Moscow District, Russia; Pushchino State Institute of Life Sciences, Pushchino, Moscow District, Russia.
Epilepsy Res. 2015 Jan;109:134-45. doi: 10.1016/j.eplepsyres.2014.10.022. Epub 2014 Nov 6.
Although the presence and importance of oscillations in cortical structures is well-documented, little is known about this rhythmic activity in subcortical areas. In waking guinea pigs, during their inattentive rest, local field potentials (LFPs) were recorded simultaneously in eight brain structures. In the cortical areas (prefrontal and entorhinal fields, hippocampus, dentate gyrus) and subcortical ones (medial and lateral septal nuclei, central nucleus of amygdala, and supramammillary nucleus), different types of oscillations were observed: delta (0.5-4Hz), theta (4-8), alpha (10-12), gamma (40-80), and high-frequency, presumable ripples (100-200Hz). In all structures, low-frequency oscillations (delta and theta) were more powerful than high-frequency ones. Structural communications in different bands of rhythmic activity were expressed differently. On the whole they were the more intensive, the stronger were the oscillations, however, this was not the absolute rule. A long-term (about a month) daily injection of l-glutamate into the medial septal region induced significant changes in theta, gamma, and high-frequency oscillations in most regions examined. The correlations of some structures also changed; they significantly decreased between the entorhinal cortex and hippocampus in the theta band and between the medial septum and central amygdala in the gamma band. During permanent septal glutamate infusion, distinct signs of epileptogenesis were revealed (epileptiform activity, seizure behavior of animals, and formation of aberrant fibers in the hippocampus). Thus, we believe that the glutamatergic system of medial septum can participate in the development of epilepsy. The earliest sign of pathology in electrical activity was alterations in high-frequency oscillations in the dentate gyrus and medial septum, but the strongest changes were in theta and especially gamma rhythms in many structures. The data obtained help to advance our understanding of the basic mechanisms of brain functioning and its disturbances in seizure pathology.
尽管皮质结构中振荡的存在及其重要性已有充分记录，但对于皮质下区域的这种节律性活动却知之甚少。在清醒的豚鼠处于非专注休息状态时，同时在八个脑结构中记录了局部场电位（LFP）。在皮质区域（前额叶和内嗅区、海马体、齿状回）和皮质下区域（内侧和外侧隔核、杏仁核中央核以及乳头体上核），观察到了不同类型的振荡：δ波（0.5 - 4Hz）、θ波（4 - 8Hz）、α波（10 - 12Hz）、γ波（40 - 80Hz）以及高频的、可能是涟漪波（100 - 200Hz）。在所有结构中，低频振荡（δ波和θ波）比高频振荡更强。不同节律活动频段中的结构通信表现各异。总体而言，振荡越强，通信就越密集，但这并非绝对规律。在内侧隔区每日长期（约一个月）注射L - 谷氨酸会在大多数检测区域引起θ波、γ波和高频振荡的显著变化。一些结构之间的相关性也发生了变化；在θ频段内嗅皮质与海马体之间以及γ频段内侧隔区与杏仁核中央核之间的相关性显著降低。在持续注入隔区谷氨酸期间，出现了明显的癫痫发生迹象（癫痫样活动、动物的癫痫发作行为以及海马体中异常纤维的形成）。因此，我们认为内侧隔区的谷氨酸能系统可能参与癫痫的发展。电活动中病理的最早迹象是齿状回和内侧隔区高频振荡的改变，但许多结构中最强的变化是在θ波，尤其是γ波节律中。所获得的数据有助于推进我们对大脑功能基本机制及其在癫痫病理中的紊乱的理解。
