Basic characteristics of epileptiform discharges triggered by lindane in rats
Abstract
Introduction: EEG is a widely used method of epilepsy examination. In order to quantitatively inspect ictal EEG findings, a number of mathematical models have been developed over the years, one of them being the Fast Fourier Transform (FFT). It transforms the signal from time domain into frequency domain, giving information about their power spectral densities (PSD). Lindane is a well-established neurotoxic agent often used in experimental studies as a model of generalized epilepsy. This study aims to quantitatively examine the characteristics of ictal EEG activity in rats on model of generalized epilepsy induced by lindane.
Materials and Methods: Wistar albino rats were used for the study. Electrodes were surgically implanted over the frontal, parietal and occipital cortices of each animal for EEG recording purposes prior to lindane administration in convulsive dose. An 8-channel EEG apparatus was used, combined with a software developed in the Laboratory (NeuroSciLaBG). Ictal EEG epochs were extracted from the original signal and FFT analysis performed to obtain information considering PSD in predefined frequency bands. Amplitude histogram feature of the software was used to differentiate ictal spikes based on their voltage.
Results: FFT analysis has yielded important information regarding spectral powers in frequency domain. Ictal EEG showed considerable stratification, theta frequency band (4-7 Hz) being markedly dominant. Amplitude histogram showed the majority of spikes to be in the voltage ranges up to 250 µV, while higher voltage spikes were rarely observed.
Conclusion: FFT is capable of giving important information about ictal period characteristics. Ictal periods induced by lindane are characterized by dominancy of theta rhythm and spiking activity mostly in amplitude bins up to 250 µV. FFT and amplitude histograms can be of critical importance in the future pharmacological and toxicity studies.
Keywords: seizures, EEG, FFT, lindane, rats
References
Duncan JS, Sander JW, Sisodiya SM, Walker MC. Adult epilepsy. Lancet 2006;367:1087 –100.
Stephen LJ, Brodie MJ. Epilepsy in elderly people. Lancet. 2000; 355:1441–1446.
Singhi P. Infectious causes of seizures and epilepsy in the developing world. Dev Med Child Neurol. 2011;53(7):600-9
Saada F, Wang ZS, Bautista RE. In focus: The everyday lives of families of adult individuals with epilepsy. Epilepsy Behav. 2015;50:10-3.
Thompson R, Kerr M, Glynn M, Linehan C. Caring for a family member with intellectual disability and epilepsy: practical, social and emotional perspectives. Seizure 2014;23:856 –63.
Noachtar S, Rémi J. The role of EEG in epilepsy: a critical review. Epilepsy Behav. 2009;15(1):22-33.
Steinhoff BJ, Scholly J, Dentel C, Staack AM. Is routine electroencephalography (EEG) a useful biomarker for pharmacoresistant epilepsy? Epilepsia. 2013;54 Suppl 2:63-6.
Bassett L, Troncy E, Pouliot M, Paquette D, Ascah A, Authier S. Telemetry video-electroencephalography (EEG) in rats, dogs and non-human primates: methods in follow-up safety pharmacology seizure liability assessments. J Pharmacol Toxicol Methods. 2014;70(3):230-40.
Frost JD Jr, Lee CL, Hrachovy RA, Swann JW. High frequency EEG activity associated with ictal events in an animal model of infantile spasms. Epilepsia. 2011;52(1):53-62.
Smith SJ. EEG in the diagnosis, classification, and management of patients with epilepsy. J Neurol Neurosurg Psychiatry. 2005;76 Suppl 2:ii2-7.
Cascino GD. Electroencephalography and epilepsy. Journal of Epilepsy. 1996;10:16-23.
National Toxicology Program.. Lindane, hexachlorocyclohexane (technical grade), and other hexachlorocyclohexane isomers. Rep Carcinog. 2011;12:256-8.
Lal R, Saxena DM. Accumulation, metabolism, and effects of organochlorine insecticides on microorganisms. Microbiol Rev. 1982;46(1):95-127.
Solomon LM, Fahrner L, West DP. Gamma benzene hexachloride toxicity: a review. Arch Dermatol 1977;113:353–357.
Wilkinson C. Is the treatment of scabies hazardous? J R Coll Gen Pract. 1988;38(315):468-9.
Danopoulos E, Melissinos K, Katsas G. Serious poisoning by hexachlorocyclohexane. Arch Indiist Hyg Chicago 1953;8:582–587.
Portig J, Schnorr C. The potency of gamma-1,2,3,4,5,6-hexachlorohexane(lindane). Toxicology 1988;52:309–321.
Aspinwall LS, Bermudez I, King LA, Wafford KA. The interactions of hexachlorocyclohexane isomers with human gamma-aminobutyric acid(A) receptors expressed in Xenopus oocytes. J Pharmacol Exp Ther. 1997;282(3):1557-64.
Hrnčić D, Rašić-Marković A, Djuric D, Šušić V, Stanojlović O. The role of nitric oxide in convulsions induced by lindane in rats. Food and Chemical Toxicology 2011; 49: 947-954.
Vucević D, Hrncić D, Radosavljević T, et al. Correlation between electrocorticographic and motor phenomena in lindane-induced experimental epilepsy in rats. Can J Physiol Pharmacol. 2008;86(4):173-9.
Stanojlović O, Nikolić T, Hrnčić D, Radonjić N, Rašić-Marković A, MladenovićD, Petronijević N. Ontogenetic influence on rat susceptibility to lindane seizure after pretreatment with phencyclidine. Environ Toxicol Pharmacol. 2013;35(2):161-70.
Stam CJ. Nonlinear dynamical analysis of EEG and MEG: review of an emerging field. Clin Neurophysiol. 2005; 116(10):2266-301.
Campbell IG. EEG recording and analysis for sleep research. Curr Protoc Neurosci. 2009; 49(1):10-2.
Honda R, Saito Y, Okumura A, et al. Characterization of ictal slow waves in epileptic spasms. Epileptic Disord. 2015;17(4):425-35.
Tononi G, Cirelli C. Time to be SHY? Some comments on sleep and synaptic homeostasis. Neural Plast. 2012;2012:415250.
Assenza G, Di Lazzaro V. A useful electroencephalography (EEG) marker of brain plasticity: delta waves. Neural Regen Res. 2015;10(8):1216-7.
Assenza G, Zappasodi F, Squitti R, et al. Neuronal functionality assessed by magnetoencephalography is related to oxidative stress system in acute ischemic stroke. Neuroimage 2009;44:1267-1273.
Finnigan SP, Rose SE, Chalk JB. Contralateral hemisphere delta EEG in acute stroke precedes worsening of symptoms and death. Clin Neurophysiol 2008;119:1690-1694.
Green, JD; Arduini A. Hippocampal activity in arousal. J Neurophysiol. 1954;17(6): 533–57.
Greenberg JA, Burke JF, Haque R, Kahana MJ, Zaghloul KA. Decreases in theta and increases in high frequency activity underlie associative memory encoding. Neuroimage. 2015;114:257-63.
Scholz S, Schneider SL, Rose M. Differential effects of ongoing EEG beta and theta power on memory formation. PLoS One. 2017;12(2):e0171913
Dadashi M, Birashk B, Taremian F, Asgarnejad AA, Momtazi S. Effects of Increase in Amplitude of Occipital Alpha & Theta Brain Waves on Global Functioning Level of Patients with GAD. Basic Clin Neurosci. 2015;6(1):14-20.
Wang R, Wang J, Yu H, Wei X, Yang C, Deng B. Power spectral density and coherence analysis of Alzheimer's EEG. Cogn Neurodyn. 2015;9(3):291-304.
Jeong J. EEG dynamics in patients with Alzheimer’s disease. Clin Neurophysiol 2004;115:1490–1505.
Moretti DV, Fracassi C, Pievani M, et al. Increase of theta/ gamma ratio is associated with memory impairment. Clin Neurophysiol 2009 ;120:295–303.