Measurement of Monoaminergic Activity by Drugs Acting on Adrenergic α2-Receptors in Rat Hippocampus and Primary Visual Cortex

Previous studies have suggested that the primary visual cortex plays a role in regulating depression, and that increases in the concentrations of the a 2-adrenoreceptor and imidazoline receptor constituted the main cause of depression. However, this hypothesis has not been scientifically proven. Hence, in this study, the selective reactants and antagonists for the a 2-adrenoceptor and imidazoline receptor were injected into rats, in order to observe any changes in the monoamine nervous. The awakening animal microdialysis technique that obstains the extracellular nerve transfer substance, while maintaining the free mobile condition of the rat, was used, in order to observe the changes in the norepinephrine, serotonin and extracellular metabolites over time, using high-performance chromatography and an electrochemical detector placed within the hippocampus and occipital cortex region. Clonidine predominantly decresed the release of MHPG, norepinephrine, DOPAC and 5-HIAA in both the dorsal hippocampus and occipital cortex regions. Yohimbine and idazoxan increased the release of MHPG, norepinephrine, DOPAC and 5- HIAA, however, the idazoxan injection group demonstrated more interference and a greater exacerbation pattern than the yohimbine injection group associated with the release of norepinephrine and 5-HIAA in the occipital cortex region. This effect was more pronounced in the primary visual cortex region. The release and replacement of the monoamine nerve transfer substance within the rat hippocampus and occipital cortex regions were increased by the selective a 2-adrenoceptor antagonist, however, the release of serotonin and norepinephrine was further hindered by this drug agent, which simultaneously antagonized the imidazoline receptor, and this effect was stronger in the occipital cortex region than in the hippocampus. This suggests that any drug which functions as an a 2-adrenoceptor antagonist could have an influence on the imidazoline receptor, and that this would be of potential value in inducing the various medical reactions associated with an antidepressant. In this study, the main function of the primary visual cortex was the maintenance and control of the level of depression, and this area of the brain was shown to be the main focus of the reactions of the antidepressant.