Advances in computer technology have allowed quantification of the electroencephalogram (EEG) and expansion of quantitative EEG (qEEG) analysis in neurophysiology, as well as clinical neurology, with great success. Among the variety of techniques in this field, frequency (spectral) analysis using Fast Fourier Transforms (FFT) provides a sensitive tool for time-course studies of different compounds acting on particular neurotransmitter systems. Studies presented here include Electrocorticogram (ECoG) analysis following exposure to a glutamic acid analogue - domoic acid (DOM), psychoactive indole alkaloid - ibogaine, as well as cocaine and gamma-hydroxybutyrate (GHB). The ECoG was recorded in conscious rats via a tether and swivel system. The EEG signal frequency analysis revealed an association between slow-wave EEG activity delta and theta and the type of behavioral seizures following DOM administration. Analyses of power spectra obtained in rats exposed to cocaine alone or after pretreatment with ibogaine indicated the contribution of the serotonergic system in ibogaine mediated response to cocaine (increased power in alpha1 band). Ibogaine also lowered the threshold for cocaine-induced electrographic seizures (increased power in the low-frequency bands, delta and theta). Daily intraperitoneal administration of cocaine for two weeks was associated with a reduction in slow-wave ECoG activity 24 hrs following the last injection when compared with controls. Similar decreased cortical activity in low-frequency bands observed in chronic cocaine users has been associated with reduced metabolic activity in the frontal cortex. The FFT analyses of power spectra relative to baseline indicated a significant energy increase over all except beta2 frequency bands following exposure to 400 and 800 mg/kg GHB. The EEG alterations detected in rats following exposure to GHB resemble absence seizures observed in human petit mal epilepsy. Spectral analysis of the EEG signals combined with behavioral observations may prove to be a useful approach in studying chronic exposure to drugs of abuse and treatment of drug dependence.
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机译：计算机技术的进步已使脑电图（EEG）的量化和神经生理学以及临床神经病学中定量脑电图（qEEG）分析的扩展得到了极大的成功。在该领域的各种技术中，使用快速傅立叶变换（FFT）进行频率（频谱）分析为敏感于特定神经递质系统的不同化合物的时程研究提供了灵敏的工具。本文介绍的研究包括暴露于谷氨酸类似物-十二烷酸（DOM），精神活性吲哚生物碱-伊博加因以及可卡因和γ-羟基丁酸酯（GHB）后的皮质电图（ECoG）分析。 ECoG通过系链和旋转系统记录在清醒大鼠中。脑电信号频率分析表明慢波脑电活动三角洲和θ与DOM管理后的行为性癫痫发作类型之间的关联。对单独暴露于可卡因或用伊博加因预处理的大鼠进行的功率谱分析表明，血清素能系统在伊波加因介导的对可卡因的反应中的贡献（α1谱带的功率增加）。依博加因还降低了可卡因引起的电图发作的阈值（低频频带，三角洲和θ的功率增加）。与对照相比，在最后一次注射后24小时，每天腹膜内给予可卡因两周与慢波ECoG活性降低有关。在慢性可卡因使用者中观察到的低频频带中类似的皮层活动减少与额叶皮层的代谢活动减少有关。相对于基线的功率谱的FFT分析表明，暴露于400和800 mg / kg GHB之后，除beta2频段以外的所有频段能量均显着增加。暴露于GHB后在大鼠中检测到的脑电图改变类似于在人类小癫痫病中观察到的癫痫发作。脑电信号的频谱分析与行为观察相结合可能被证明是研究慢性暴露于滥用药物和药物依赖治疗的有用方法。
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