Methodologic recommendations and possible interpretations of video‐EEG recordings in immature rodents used as experimental controls: A TASK1‐WG2 report of the ILAE/AES Joint Translational Task Force

Abstract

SummaryThe use of immature rodents to study physiologic aspects of cortical development requires high‐quality recordings electroencephalography (EEG) with simultaneous video recording (vEEG) of behavior. Normative developmental vEEG data in control animals are fundamental for the study of abnormal background activity in animal models of seizures or other neurologic disorders. Electrical recordings from immature, freely behaving rodents can be particularly difficult because of the small size of immature rodents, their thin and soft skull, interference with the recording apparatus by the dam, and other technical challenges. In this report of the TASK1 Working Group 2 (WG2) of the International League Against Epilepsy/American Epilepsy Society (ILAE/AES) Joint Translational Task Force, we provide suggestions that aim to optimize future vEEG recordings from immature rodents, as well as their interpretation. We focus on recordings from immature rodents younger than 30 days old used as experimental controls, because the quality and correct interpretation of such recordings is important when interpreting the vEEG results of animals serving as models of neurologic disorders. We discuss the technical aspects of such recordings and compare tethered versus wireless approaches. We also summarize the appearance of common artifacts and various patterns of electrical activity seen in young rodents used as controls as a function of behavioral state, age, and (where known) sex and strain. The information herein will hopefully help improve the methodology of vEEG recordings from immature rodents and may lead to results and interpretations that are more consistent across studies from different laboratories.

Antiepileptogenesis and disease modification: Progress, challenges, and the path forward—Report of the Preclinical Working Group of the 2018 NINDS‐sponsored antiepileptogenesis and disease modification workshop

“…6,7 The three priorities in the vision to transform epilepsy research and care were the development of AEG and DM treatments and treatments for drug-resistant seizures and comorbidities. 6 The ILAE/AES Joint Translational Task Force spearheaded an international collaboration of expert working group members who developed proposals for harmonizing the methodology and interpretation of video-electroencephalography (vEEG) studies in rodent models (TASK1), [8][9][10][11][12][13] undertook a systematic review on outcome measures in preclinical epilepsy studies (TASK2), 14 created preclinical epilepsy research common data elements (CDEs) to improve across-studies comparisons, study reporting, and collaborative research (TASK3), [15][16][17][18][19][20][21] and proposed infrastructure for multicenter preclinical trials for epilepsy therapy development (TASK4). 22…”

Phenotypic analysis of catastrophic childhood epilepsy genes

“…Seizure classifications promoted by the International League Against Epilepsy (ILAE) 33 are largely defined by the presence of unprovoked “self-sustained paroxysmal disorders of brain function” and these classification resources have evolved continuously since the 1960s. However, adaptation of this strategy to animal models 34 , specifically zebrafish models developed for catastrophic epilepsies of childhood, is difficult. Because electrophysiological monitoring is a critical component of clinical diagnosis, we primarily focused our phenotyping effort on describing the full spectrum of electrical events encountered.…”

Phenotypic analysis of catastrophic childhood epilepsy genes: The Epilepsy Zebrafish Project

“…However, adaptation of this classification strategy to animal models 34 , specifically zebrafish models developed for catastrophic epilepsies of childhood, is lacking. Because clinical seizure classifications promoted by the International League Against Epilepsy (ILAE) 33 are defined by the presence of unprovoked "self-sustained paroxysmal disorders of brain function", we focused our phenotyping effort on developing a standardized seizure classification scheme using electrophysiology data.…”