Methods: Using a pilocarpine-induced epileptic mouse model, sensory-motor and visual cortical slices were prepared, and the whole-cell patch clamp technique was used to record spontaneous inhibitory post-synaptic currents (sIPSCs).
Results: The primary finding was that the mean amplitude of sIPSC from the sensory-motor cortex increased significantly in epileptic mice when the recording pipette contained MK-801 compared to control mice, whereas the mean sIPSC frequency was not significantly different, indicating that post-synaptic mechanisms are involved. However, there was no significant pre-synaptic inhibition through preNMDARs in the acute brain slices from pilocarpine-induced epileptic mice.
Conclusion: In the acute case of epilepsy, a compensatory mechanism of post-synaptic inhibition, possibly from ambient GABA, was observed through changes in the amplitude without significant changes in the frequency of sIPSC compared to control mice. The role of preNMDAR-mediated inhibition in epileptogenesis during the chronic condition or in the juvenile stage warrants further investigation.
METHODS: The behavioral and neurophysiological effects of MFA were investigated in mice with and without FMZ pre-treatment. The elevated zero maze (EZM) and marble burying tests were used to assess anxiety-like behaviors and burying activities, respectively. The standard bar test was used to evaluate catalepsy, while the actophotometer test was used to measure locomotor activity. Seizure intensity was scored, and fatalities were counted.
RESULTS: Without FMZ pre-treatment, MFA induced behavioral and neurophysiological effects in a dose-dependent manner as follows: At a dose of 20 mg/kg, i.p, MFA-treated mice exhibited anxiety-like behaviors, which was determined by a significant increase in the time spent in the closed areas and a significant decrease in the number of entries to the open areas of the EZM apparatus. These mice also showed a significant decrease in the burying activity, manifested as a significant decrease in the number of buried marbles. At 40 mg/kg, i.p., MFA-treated mice showed catalepsy that was associated with a significant decrease in locomotor activity. At a dose of 80 mg/kg, i.p., mice developed fatal tonic-clonic seizures (seizure score = 4). Pre-treatment with FMZ (5 mg/kg, i.p.) significantly reversed the anxiety-like behaviors and restored marble-burying activity. Additionally, FMZ prevented catalepsy, significantly restored locomotor activity, reduced seizure intensity (seizure score = 0.3) and significantly reduced mortalities.
CONCLUSIONS: The present study's findings indicate that activation of the GABAAR is involved in the CNS toxicity of MFA, and FMZ reverses MFA toxicity by interfering with this receptor.
Materials and Methods: The study started with the identification of selected LAB by 16S rRNA, followed by optimization of GABA production by culture conditions using different initial pH, temperature, glutamate concentration, incubation time, carbon, and nitrogen sources. 16S rRNA polymerase chain reaction and analysis by phylogenetic were used to identify Lactobacillus plantarum (coded as N5) responsible for the production of GABA.
Results: GABA production by high-performance liquid chromatography was highest at pH of 5.5, temperature of 36°C, glutamate concentration of 500 mM, and incubation time of 84 h. Peptone and glucose served as the nitrogen and carbon sources, respectively, whereas GABA was produced at optimum fermentation condition of 211.169 mM.
Conclusion: Production of GABA by L. plantarum N5 was influenced by initial pH of 5.5, glutamic acid concentration, nitrogen source, glucose as carbon source, and incubation temperature and time.