Addiction Research & Therapy

Solvent inhalant abuse is widely spread allover the world; especially among adolescents. Solvent inhalants were found to be

highly toxic and extremely deleterious to the addicts' health and societies. Numerous studies were undertaken to investigate

the neurophysiologic and biochemical mechanisms through which these substances produce their toxicity. Th is study was

devoted to investigate the eff ect of Toluene on brain neurotransmitters aft er its single and repeated inhalation in rats.

Levels of Glutamate, GABA, dopamine and 5 HT were measured in rat's brain homogenate aft er single and repeated daily

inhalation of Toluene in 2 concentrations.

Results revealed that Toluene signifi cantly (P<0.01) increase the level of glutamate of in rat's brain in a concentrationdependent

manner. Besides, single and repeated daily inhalation of the two concentrations of Toluene signifi cantly decreased

GABA level in rat's brain. Single inhalation of Toluene also increased 5-HT level in rat brain, but this increase was insignifi cant

compared to the control group. However, repeated daily inhalation of the two concentrations of Toluene in both concentrations

signifi cantly increased 5-HT level in rat brain. Both single and repeated daily inhalation of the two concentrations of Toluene

also signifi cantly increased dopamine level in rat’s brain.

Th erefore, single and daily repeated Toluene inhalation signifi cantly alter levels of brain neurotransmitters. Toluene

increases levels of glutamate; the "excitatory" neurotransmitter; and decreases levels of GABA; the "inhibitory" neurotransmitter.

Toluene single and repeated daily inhalation increases 5-HT and dopamine levels in rat’s brain. Th ese results could explain the

various behavioral changes induced by inhalation of this toxic solvent inhalant.