In conclusion, SHR provide a good model for ADHD symptoms. Disturbances that have been identified in the central nervous system of SHR have provided insight into the possible neurogenesis of the behavioral disturbances of ADHD. Evidence suggests that the most frequently prescribed psychostimulants, D-amphetamine and methylphenidate, alleviate ADHD symptoms by blocking dopamine reuptake, which increases dopamine availability at postsy-naptic and extrasynaptic receptors not only following impulse-triggered release of dopamine from mesolimbic, mesocortical, and nigrostriatal dopamine nerve terminals, but also following glutamate-stimulated release of dopamine from mesolimbic terminals in the nucleus accumbens shell. The nucleus accumbens shell plays an important role in the integration of afferent signals from limbic areas of the brain, particularly the amygdala, hippocampal formation, prefrontal cortex, and cingulate cortex. Transmission of these signals to motor areas of the brain is modulated by mesolimbic dopamine input, which gives rise to reinforcement of appropriate behavior (71). The evidence is consistent with a deficiency in the dopaminergic sytem contributing to the behavioral disturbances of SHR.
Was this article helpful?