Department of Bioinformatics, Graduate School of Engineering, Soka University, 1-236 Tangi-cho, Hachioji, Tokyo, Japan.
Epilepsy Res. 2011 Jun;95(1-2):144-51. doi: 10.1016/j.eplepsyres.2011.03.015. Epub 2011 Apr 16.
Kindling is a widely used animal model of intractable temporal lobe epilepsy. In the present study, we performed fast Fourier transformation (FFT) analysis of kindling-induced afterdischarge (AD) in the rabbit hippocampus. Ten adult rabbits were used. Kindling stimulation to the right hippocampus was delivered as a train of biphasic pulses (1 ms duration each) of 50 Hz for 1s, with suprathreshold intensity for AD. Motor responses were classified into five stages according to the conventional criteria. Of 10 animals, five developed stage 5 convulsions with a mean of 21 stimulations (kindled (K) group), while the remaining five animals did not (incomplete kindling (IK) group). We standardized each ratio of power spectral density of lower frequency band component (LFB: 0-9 Hz) and the higher frequency band (HFB: 12-30 Hz) in the initial stage as 1.0. The IK group exhibited small decrements (0.99 and 0.94 times) in LFB and HFB components at the final stage. In contrast, the K group exhibited a significantly (p<0.05) large decrement (0.49 times) in the LFB component and a very large increment (4.45 times) of HFB component at the final stage. Correlation analyses were performed between alteration of power spectral density ratio of the HFB component and AD duration, interictal discharge frequency, and behavioral stage during kindling progression. Fairly strong positive correlations were found in all cases in the K group. FFT analysis of kindling-induced AD demonstrated an important role of the HFB component: enhancement of the HFB component is associated with kindled stage, while decrement of it is associated with incomplete kindling stage. These findings suggest that FFT analysis of stimulus-induced and spontaneous seizure discharges is useful for examination of the progression of epileptic disorders.
点燃是一种广泛使用的难治性颞叶癫痫动物模型。在本研究中，我们对兔海马点燃诱导的后放电（AD）进行了快速傅里叶变换（FFT）分析。使用 10 只成年兔。对右侧海马进行双相脉冲（每个脉冲持续 1 ms）刺激，频率为 50 Hz，强度超过 AD 阈值。根据传统标准，将运动反应分为五个阶段。在 10 只动物中，有 5 只发展为 5 级抽搐，平均需要 21 次刺激（点燃（K）组），而其余 5 只动物则没有（不完全点燃（IK）组）。我们将初始阶段低频带成分（LFB：0-9 Hz）和高频带（HFB：12-30 Hz）的功率谱密度比标准化为 1.0。IK 组在最后阶段 LFB 和 HFB 成分的减少幅度较小（0.99 和 0.94 倍）。相比之下，K 组在最后阶段 LFB 成分的减少幅度显著（p<0.05）（0.49 倍），HFB 成分的增加幅度非常大（4.45 倍）。在 K 组中，对 HFB 成分功率谱密度比的变化与 AD 持续时间、发作间期放电频率和点燃进展期间的行为阶段进行了相关性分析。在所有情况下都发现了相当强的正相关。对点燃诱导 AD 的 FFT 分析表明 HFB 成分的重要作用：HFB 成分的增强与点燃阶段有关，而其减少与不完全点燃阶段有关。这些发现表明，刺激诱导和自发性癫痫放电的 FFT 分析有助于检查癫痫疾病的进展。
