Effects of toluene exposure during brain growth spurt on GABA(A) receptor-mediated functions in juvenile rats.
نویسندگان
چکیده
Toluene is a commonly abused inhalant. Its neurobiological effects are, at least in part, mediated by gamma-aminobutyric acid (GABA(A)) receptors. Since GABA(A) receptor function is critical during brain development, the long-term effects of toluene exposure during brain growth spurt were investigated. Spargue-Dawley male rats were administered with toluene (500 mg/kg, i.p.) on postnatal day (PN) 4-9. Behavioral and electrophysiological measures and the levels of messenger RNA (mRNA) expression of GABA(A) receptor subunits were examined on PN 28-32. The seizure sensitivity induced by bicuculline (a GABA(A) receptor antagonist), methyl beta-carboline-3-carboxylate (inverse agonists of the GABA(A)/benzodiazepine receptor) but not 3-mercaptopropionic acid (a glutamate decarboxylase inhibitor) was enhanced by toluene exposure. Toluene exposure had no effect on the performance in the elevated plus-maze and rotarod test but reduced the responses to diazepam in these two tests. In vitro intracellular electrophysiological recordings employing brain slices from rats treated with toluene demonstrated a significant decrease in GABA(A) receptor-mediated inhibitory postsynaptic currents in CA1 neurons but an increased response to GABA perfusion. The relative abundance of the mRNAs encoding various subunits of GABA(A) receptor (alpha1, alpha2, alpha4, alpha5, alpha6, beta2, beta3, gamma2S, gamma2L) was examined in four brain regions (hippocampus, striatum, cortex, and cerebellum) by semiquantitative reverse transcription-PCR. These results demonstrated that subunit- and brain area-selective alterations in GABA(A) receptors after toluene exposure during brain growth spurt. The alterations in GABA(A) receptors might be associated with the neurobehavioral disturbance in offspring of toluene-abusing women.
منابع مشابه
Toluene exposure during the brain growth spurt reduced behavioral responses to nicotine in young adult rats: a potential role for nicotinic acetylcholine receptors in fetal solvent syndrome.
Toluene, an industrial organic solvent, is voluntarily inhaled as drug of abuse. Toluene has been shown to inhibit the nicotinic acetylcholine receptors. Nicotinic receptors play an important role in brain development during brain growth spurt and early adolescence. The long-term effects of neonatal and adolescent toluene exposure on behavioral responses to nicotine in early adulthood were comp...
متن کاملBrain Tissues Oxidative Damage as a Possible Mechanism of Deleterious Effects of Propylthiouracil- Induced Hypothyroidism on Learning and Memory in Neonatal and Juvenile Growth in Rats
Introduction: The role of brain tissues oxidative damage in learning and memory impairments has been well documented. It is also well known that thyroid hormones have a critical role for the brain functions. The purpose of this study was to investigate the role of brain tissues oxidative damage as a possible mechanism of deleterious effects of propylthiouracil (PTU) - induced hypothyroidism on ...
متن کاملFear and anxiety behavior in rats
Fear can be considered as a functional defense behavior to protect living beings against dangerous situation. In our studies we have investigated the fear behavior in rats in elevated plus maze .The increase in two parameters percent of open arm entries (%OAE) and percent of time spent in the open arms (% OAT) and decrease in the percent of time spent in closed arm (%CAT) was considered as fear...
متن کاملFear and anxiety behavior in rats
Fear can be considered as a functional defense behavior to protect living beings against dangerous situation. In our studies we have investigated the fear behavior in rats in elevated plus maze .The increase in two parameters percent of open arm entries (%OAE) and percent of time spent in the open arms (% OAT) and decrease in the percent of time spent in closed arm (%CAT) was considered as fear...
متن کاملEffects of prenatal exposure to different colors on offsprings mood
Objective(s):There is much evidence indicating that depression is influenced by the levels of neurotransmitters such as dopamine, GABA and adrenaline. The current study we designed to investigate the effect of exposure of pregnant rats to different colors on neurotransmitters level, as indicators of mood disorders in off springs. Materials and Methods:Five groups of pregnant female Wistar rats ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Toxicological sciences : an official journal of the Society of Toxicology
دوره 95 2 شماره
صفحات -
تاریخ انتشار 2007