Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL, USA.
Department of Physiology, Wayne State University, Detroit, MI, USA.
Epilepsy Behav. 2021 Jan;114(Pt A):107652. doi: 10.1016/j.yebeh.2020.107652. Epub 2020 Dec 10.
Epilepsy is a debilitating neurological condition characterized by spontaneous seizures as well as significant comorbid behavioral abnormalities. In addition to seizures, epileptic patients exhibit interictal spikes far more frequently than seizures, often, but not always observed in the same brain areas. The exact relationship between spiking and seizures as well as their respective effects on behavior are not well understood. In fact, spiking without overt seizures is seen in various psychiatric conditions including attention-deficit hyperactivity disorder.
In order to study the effects of spiking and seizures on behavior in an epileptic animal model, we used long-term video-electroencephalography recordings at six cortical recording sites together with behavioral activity monitoring. Animals received unilateral injections of tetanus toxin into either the somatosensory or motor cortex.
Somatosensory cortex-injected animals developed progressive spiking ipsilateral to the injection site, while those receiving the injection into the motor cortex developed mostly contralateral spiking and spontaneous seizures. Animals with spiking but no seizures displayed a hyperactive phenotype, while animals with both spiking and seizures displayed a hypoactive phenotype. Not all spikes were equivalent as spike location strongly correlated with distinct locomotor behaviors including ambulatory distance, vertical movements, and rotatory movement.
Together, our results demonstrate relationships between brain region-specific spiking, seizures, and behaviors in rodents that could translate into a better understanding for patients with epileptic behavioral comorbidities and other neuropsychiatric disorders.
癫痫是一种使人衰弱的神经疾病，其特征是自发性发作以及严重的共患行为异常。除了发作外，癫痫患者的发作间期棘波比发作更为频繁，这些棘波经常出现在同一脑区，但并非总是如此。棘波与发作之间的确切关系以及它们各自对行为的影响还不是很清楚。事实上，在各种精神疾病中，包括注意力缺陷多动障碍，都可见到没有明显发作的棘波。
为了在癫痫动物模型中研究棘波和发作对行为的影响，我们使用了在六个皮质记录部位进行的长期视频脑电图记录以及行为活动监测。动物接受了破伤风毒素单侧注射，注射部位分别在体感或运动皮质。
体感皮质注射的动物出现了与注射部位同侧的进行性棘波，而接受运动皮质注射的动物则主要出现对侧棘波和自发性发作。只有棘波而没有发作的动物表现出多动表型，而既有棘波又有发作的动物表现出活动减少表型。并非所有的棘波都是等同的，因为棘波的位置与不同的运动行为密切相关，包括步行距离、垂直运动和旋转运动。
总的来说，我们的结果表明，在啮齿动物中，特定脑区的棘波、发作和行为之间存在关系，这可能有助于更好地理解癫痫伴行为障碍和其他神经精神疾病患者。
