Two Types of Seizures in Homocysteine Thiolactone-Treated Adult Rats, Behavioral and Electroencephalographic Study

Abstract

D,L-homocysteine thiolactone (H), a reactive homocysteine metabolite, contributes to total homocysteine pool. The aim of the present study was to determine the effects of H after acute application in increasing doses to rats. Adult Wistar rat were intraperitoneally administered saline or H in increasing doses (5.5, 8.0, or 11.0 mmol/kg). For electroencephalographic (EEG) recordings, three gold-plated screws were implanted into the skull and animals were supervised. We observed H-induced two types of seizures, the coexistence of convulsive and nonconvulsive epilepsy. Dose-related increase in the number and severity (0-4) of displaying convulsions was recorded. In H(5.5) group, the majority of seizure episodes were grade 1 (62.5 and 0% lethality), in H(8) 40% grade 2, and in H(11) grade 4 in 42.11% (100% lethal outcome). EEGs recordings in convulsive animals showed a high-voltage spike-wave and polyspikes complexes. The second, absence-like, nonconvulsive seizures were accompanied by the EEGs mostly with 6-8 Hz spikes-and-wave discharges (SWD). Latency time to the generalized clonic-tonic seizures overlapped with the time of the maximal median number and median duration of the SWD per 15 min during 90-min observing period. The results show that acute H administration significantly changes neurons, EEG tracings, and behavioral responses and suggests a possible model for studying petit mal epilepsy.

Finasteride improves motor, EEG, and cellular changes in rat brain in thioacetamide-induced hepatic encephalopathy

“…Ambient noise was eliminated using a 50-Hz notch filter. Data acquisition and signal processing were performed with LabVIEW platform software developed in the Laboratory NeuroSciLaBG (26,53). EEG was analyzed every 30 min in the period 22-24 h after the administration of the last dose of TAA (at time points 22.5, 23, and 23.5 h).…”

Homocysteine: Neurotoxicity and mechanisms of induced hyperexcitability

“…Hyperhomocysteinemia in awake adult male Wistar rats induced a generalised seizure disorder characterised by recurrent unprovoked clonic-tonic convulsions and absence-like seizures as well as epileptic electrical discharges. In addition to a prolonged median latency to the first seizure, the seizure incidence, median seizure episode severity and median number of seizure episodes per rat were significantly higher in all Hcy treated groups (39). Non-convulsive status epilepticus can occur from a variety of causes, including primarily generalised absence epilepsy, genetic origins (Wakayama or tremor epileptic rats) or pharmacologically (penicillin, pentylenetetrazole or γ-hydroxy-butyric acid) induced models (40).…”

“…Following the work of Djuric's study, Stanojlovic et al administered homocysteine (i.p.) to adult rats, and for the first time, convulsive and non-convulsive seizures were recorded (39). This form of epilepsy was followed by two-wave patterns of seizures with one replacing the other.…”

“…This form of epilepsy was followed by two-wave patterns of seizures with one replacing the other. It has been suggested that D,L-homocysteine thiolactone may be considered as an excitatory metabolite, which is capable of becoming a natural convulsant if accumulated to a great extent in the brain (39). Hyperhomocysteinemia in awake adult male Wistar rats induced a generalised seizure disorder characterised by recurrent unprovoked clonic-tonic convulsions and absence-like seizures as well as epileptic electrical discharges.…”

Exploratory behavior alteration as an epileptic comorbidity in elevated plus maze test

“…The seizures were assessed by their incidence severity, duration and latency. Seizure intensity was determined by a modified descriptive rating scale reported by Stanojlović et al (12) with grades defined as: grade 1 -head nodding, lower jaw twitching; grade 2 -myoclonic body jerks (hot plate reaction), bilateral forelimb clonus with full rearing (Kangaroo position); grade 3 -progression to generalized clonic convulsions followed by tonic extension of fore-and hind limbs and tail and grade 4 -prolonged severe tonic-clonic convulsions lasting over 10 sec (status epilepticus) or frequent repeated episodes of clonic convulsions for an ex-…”