Synaptosomal GABA uptake decreases in paraoxon-treated rat brain

The Dynamics of Autism Spectrum Disorders: How Neurotoxic Compounds and Neurotransmitters Interact

“…These results were confirmed by a study by Mohammadi et al . [78], reporting a significant decrease of GABA uptake by synaptosomes derived from the hippocampus and cortex of adult male Wistar rats after exposure to 0.1, 0.3 and 0.7 mg/kg of paraoxon. However, an increase in synaptosomal GABA uptake was reported after exposure of synaptosomes from male Wistar rats to lower concentrations (10 −8 –10 −6 M) of paraoxon for 20 min while GABA uptake was decreased after exposure to higher concentrations (10 −5 –10 −3 M).…”

Comments on Quaak, et al. The Dynamics of Autism Spectrum Disorders: How Neurotoxic Compounds and Neurotransmitters Interact. Int. J. Environ. Res. Public Health 2013, 10, 3384–3408

“…Although the authors present findings of our studies published in 2007 [2] and 2008 [3], there are some errors in the interpretation of our results that should be explained as follows:…”

“…The authors indicated “Mohammadi et al reported a significant decrease of GABA uptake by synaptosomes derived from the hippocampus and cortex of adult male Wistar rats after exposure to 0.1, 0.3 and 0.7 mg/kg of paraoxon”. In the study conducted by Mohammadi et al [3], male Wistar rats were given a single intraperitoneal injection of one of three doses of paraoxon (0.1, 0.3, or 0.7 mg/kg) and [ 3 H]GABA uptake was measured in synaptosomes prepared from cerebral cortex and hippocampus. The results showed that the GABA uptake was significantly reduced by both cerebral and hippocampal synaptosomes, only in animals treated with the convulsive dose (0.7 mg/kg) of paraoxon.…”

Low concentrations of methamidophos do not alter AChE activity but modulate neurotransmitters uptake in hippocampus and striatum in vitro

“…However many studies regarding the relationship between GABA levels or GABA uptake and neurotoxicants are still contradictory. Paraoxon has been reported to decrease GABA uptake in rat cerebellar, cortical and hippocampal synaptosomes (Shahroukhi et al, 2007;Mohammadi et al, 2008). Using Soman in an ex vivo model, Shih and McDonough (1997) have demonstrated an increase in GABA content in various brain regions measured 20 and 80 min post seizure development, indicating increase in GABA release.…”

“…Controlling this neuronal excitability is one of the roles of the inhibitory neurotransmitter GABA (Mazurkiewicz et al, 1999;Bahena-Trujillo and Arias-Montano, 1999). Some studies have shown that Paraoxon intoxication can alter GABA uptake and its levels in rat brain, triggering seizures when administered in rodents (Kar and Matin, 1972;Mohammadi et al, 2008).…”