Relationship of Dopamine of the Nucleus Accumbens with Intra-infralimbic Apomorphine Microinjection

Abstract

<br/><br/><em><span style="font-size: xx-small;">Objective(s): </span></em><br/><span style="font-family: Cambria Math,Cambria Math; font-size: xx-small;">The dopamine level of the nucleus accumbens changes during some stereotyped behaviors. To study dopamine level of the nucleus accumbens in intra infralimbic apomorphine-induced climbing, microdialysis probes were implanted into the nucleus accumbens shell of male Sprague Dawley rats weighting 275–400 g. </span><br/> <br/>Materials and Methods: <br/><span style="font-family: Cambria Math,Cambria Math; font-size: xx-small;"><span style="font-family: Cambria Math,Cambria Math; font-size: xx-small;">The rats were divided into two groups (apomorphine and control) of least eleven rats in each group. Apomorphine at dose of 5 μg/0.5 μl or its vehicle was microinjected into the infralimbic in apomorphine and control groups respectively. Then, changes in dopamine levels in the nucleus accumbens shell were monitored. The concentration of dopamine was measured by High-Performance Liquid Chromatography-Electochemical (HPLC-ECD). Finally, the stereotyped behaviors were recorded. </span></span><br/>Results: <br/><span style="font-family: Cambria Math,Cambria Math; font-size: xx-small;"><span style="font-family: Cambria Math,Cambria Math; font-size: xx-small;">The mean of dopamine levels for all of after microinjection period in control and drug groups were 450% and 150% respectively compared to those of before microinjection period. However, there was no significant difference between groups of apomorphine and control. In addition, the return of dopamine level to the baseline was faster in apomorphine group than the control group. </span></span><br/>Conclusion: <br/><span style="font-family: Cambria Math,Cambria Math; font-size: xx-small;"><span style="font-family: Cambria Math,Cambria Math; font-size: xx-small;">The intra infralimbic apomorphine -induced climbing at dose of 5 μg/0.5 μl was not modulated via the increase of dopamine level in the nucleus accumbens area. </span></span>