Laboratory of Animal and Human Physiology, Department of Biological Applications and Technology, Faculty of Health Sciences, University of Ioannina, 45110, Greece.
Neuroscience. 2024 Apr 5;543:108-120. doi: 10.1016/j.neuroscience.2024.02.019. Epub 2024 Feb 23.
The aim was to investigate the long-term effects of a single episode of immature Status Epilepticus (SE) on the excitability of the septal and temporal hippocampus in vitro, by studying the relationship between interictal-like epileptiform discharges (IEDs) and high-frequency oscillations (HFOs; Ripples, Rs and Fast Ripples, FRs). A pentylenetetrazol-induced Status Epilepticus-(SE)-like generalized seizure was induced at postnatal day 20 in 22 male and female juvenile rats, sacrificed >40 days later to prepare hippocampal slices. Spontaneous IEDs induced by Mg-free ACSF were recorded from the CA3 area of temporal (T) or septal (S) slices. Recordings were band-pass filtered off-line revealing Rs and FRs and a series of measurements were conducted, with mean values compared with those obtained from age-matched controls (CTRs). In CTR S (vs T) slices, we recorded longer R & FR durations, a longer HFO-IED temporal overlap, higher FR peak power and more frequent FR initiation preceding IEDs (% events). Post-SE, in T slices all types of events duration (IED, R, FR) and the time lag between their onsets (R-IED, FR-IED, R-FR) increased, while FR/R peak power decreased; in S slices, the IED 1st population spike and the FR amplitudes, the R and FR peak power and the (percent) events where Rs or FRs preceded IEDs all decreased. The CA3 IED-HFO relationship offers insights to the septal-to-temporal synchronization patterns; its post-juvenile-SE changes indicate permanent modifications in the septotemporal excitability gradient. Moreover, these findings are in line to region-specific regulation of various currents post-SE, as reported in literature.
目的是通过研究发作间期样癫痫样放电（IEDs）与高频振荡（HFOs；Ripples、Rs 和 Fast Ripples、FRs）之间的关系，来研究单次未成熟癫痫持续状态（SE）对体外隔核和颞叶海马兴奋性的长期影响。在 22 只雄性和雌性幼年大鼠出生后第 20 天，用戊四氮诱导 SE 样全身性癫痫发作，然后在 >40 天后处死大鼠，制备海马切片。从颞叶（T）或隔核（S）切片的 CA3 区记录无镁 ACSF 诱导的自发性 IEDs。离线对 Rs 和 FR 进行带通滤波，并进行一系列测量，将平均值与年龄匹配的对照（CTRs）进行比较。在 CTR S（与 T 相比）切片中，我们记录到更长的 R & FR 持续时间、更长的 HFO-IED 时间重叠、更高的 FR 峰值功率以及在 IED 之前更频繁的 FR 起始（%事件）。在 SE 后，T 切片中所有类型的事件持续时间（IED、R、FR）及其起始之间的时间滞后（R-IED、FR-IED、R-FR）增加，而 FR/R 峰值功率降低；在 S 切片中，IED 第 1 个群体峰和 FR 振幅、R 和 FR 峰值功率以及 FR 或 Rs 先于 IED 的（%）事件都减少了。CA3 IED-HFO 关系提供了深入了解隔核到颞叶同步模式的见解；其 SE 后变化表明，在隔核-颞叶兴奋性梯度中存在永久性改变。此外，这些发现与文献中报道的 SE 后各种电流的区域特异性调节一致。
