Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Mexico.
Behav Neurol. 2020 Mar 9;2020:4385706. doi: 10.1155/2020/4385706. eCollection 2020.
Physiological behaviours such as the sleep-wake cycle and exploratory behaviours are important parameters in intact and sham-operated animals and are usually thought to be unaffected by experimental protocols in which neurosurgery is performed. However, there is insufficient evidence in the literature on the behavioural and cognitive effects observed after deep microelectrode implantation surgery in animal models of neurological diseases. Similarly, in studies that utilize animal models of neurological diseases, the impact of surgery on the pathological phenomena being studied is often minimized. Based on these considerations, we performed a temporal analysis of the effects of deep microelectrode implantation surgery in the hippocampus of rats on quiet wakefulness, sleep, and exploratory activity and the pathological behaviours such as convulsive seizures according to the Racine scale. Male Wistar rats (210-300 g) were used and grouped in sham and epileptic animals. Single doses of pilocarpine hydrochloride (2.4 mg/2 l; i.c.v.) were administered to the animals to generate spontaneous and recurrent seizures. Deep microelectrode implantation surgeries in both groups and analysis of Fast ripples were performed. Physiological and pathological behaviours were recorded through direct video monitoring of animals (24/7). Our principal findings showed that in epileptic animals, one of the main behaviours affected by surgery is sleep; as a consequence of this behavioural change, a decrease in exploratory activity was also found as well as the mean time spent daily in seizures of scale 4 and the number of seizure events of scales 4 and 5 was increased after surgery. No significant correlations between the occurrence of FR and seizure events of scale 4 (rho 0.63, value 0.25) or 5 (rho -0.7, value 0.18) were observed. In conclusion, microelectrode implantation surgeries modified some physiological and pathological behaviours; therefore, it is important to consider this fact when it is working with animal models.
生理行为，如睡眠-觉醒周期和探索行为，是完整和假手术动物的重要参数，通常认为不受神经外科手术实验方案的影响。然而，在神经疾病动物模型中，深部微电极植入手术后观察到的行为和认知影响的文献证据不足。同样，在利用神经疾病动物模型的研究中，手术对正在研究的病理现象的影响往往被最小化。基于这些考虑，我们根据 Racine 量表对大鼠海马深部微电极植入手术对安静觉醒、睡眠和探索活动以及癫痫发作等病理性行为的影响进行了时间分析。使用雄性 Wistar 大鼠（210-300g），并分为假手术和癫痫动物组。向动物单次给予盐酸毛果芸香碱（2.4mg/2l；icv）以产生自发性和复发性癫痫发作。对两组动物进行深部微电极植入手术，并进行快速涟漪分析。通过对动物的直接视频监测记录生理和病理行为（24/7）。我们的主要发现表明，在癫痫动物中，手术主要影响的行为之一是睡眠；由于这种行为改变，还发现探索活动减少，以及每天处于 4 级癫痫发作的平均时间和 4 级和 5 级癫痫发作事件的数量增加。未观察到 FR 的发生与 4 级（rho 0.63， 值 0.25）或 5 级（rho -0.7， 值 0.18）癫痫发作事件之间存在显著相关性。总之，微电极植入手术改变了一些生理和病理行为；因此，在使用动物模型时，考虑到这一事实非常重要。
