[P3-17] The Effects of the expression of corticosterone and glucocorticoid receptor in brain regions of young SHR on attention maintenance
Objective: To explore the expression of corticosterone(CORT) and glucocorticoid receptor(GR) in spontaneously hypertensive rat (SHR) by methylphenidate(MPH).
Method: P21(postnatal day 21) male SHR were randomly divided into MPH group and control group, 20 rats in each group respectively. The MPH group rats were administrated by MPH 4mg/kg.d twice a day for 14 days. The levels of CORT in CSF were tested by high performance liquid chromatography, while the expression of serum CORT and GR in brain were tested by immunohistochemical analysis. The open-field test and the LAT maze were evaluated the hyperactivity and attention behavior of the rats.
Results: (1) After intervention with MPH, the behavior performances had improved both in the open-field test and the LAT maze.(2) The CORT level in the hippocampus (6.60±2.97ng/ml) had obviously increased after MPH administration(P= 0.002).(3)The expression of GR/CORT in hippocampus (16.35 ± 6.27 ng/ml; 160.60± 77.06)and the prefrontal region (15.66 ± 8.30 ng/ml; 157.84 ± 41.90) had both increased(P<0.05) by MPH. (4) Correlation analysis showed that the CORT levels and GR expression in the hippocampus had an negatively correlated with behavioral performance.The lower serum CORT levels, the more obvious the symptoms of ADHD.
Conclusion: MPH can increase the expression of CORT/GR, then improve ADHD core symptom. The lower GR expression may contribute to the lower activity of HPA axis in ADHD model.
Keywords: attention deficit hyperactivity disorder, corticosterone, glucocorticoid receptor, spontaneously hypertensive rats
Acknowledgements
Supported by the grant from National Natural Science Funds of China (81371262)
Method: P21(postnatal day 21) male SHR were randomly divided into MPH group and control group, 20 rats in each group respectively. The MPH group rats were administrated by MPH 4mg/kg.d twice a day for 14 days. The levels of CORT in CSF were tested by high performance liquid chromatography, while the expression of serum CORT and GR in brain were tested by immunohistochemical analysis. The open-field test and the LAT maze were evaluated the hyperactivity and attention behavior of the rats.
Results: (1) After intervention with MPH, the behavior performances had improved both in the open-field test and the LAT maze.(2) The CORT level in the hippocampus (6.60±2.97ng/ml) had obviously increased after MPH administration(P= 0.002).(3)The expression of GR/CORT in hippocampus (16.35 ± 6.27 ng/ml; 160.60± 77.06)and the prefrontal region (15.66 ± 8.30 ng/ml; 157.84 ± 41.90) had both increased(P<0.05) by MPH. (4) Correlation analysis showed that the CORT levels and GR expression in the hippocampus had an negatively correlated with behavioral performance.The lower serum CORT levels, the more obvious the symptoms of ADHD.
Conclusion: MPH can increase the expression of CORT/GR, then improve ADHD core symptom. The lower GR expression may contribute to the lower activity of HPA axis in ADHD model.
Keywords: attention deficit hyperactivity disorder, corticosterone, glucocorticoid receptor, spontaneously hypertensive rats
Acknowledgements
Supported by the grant from National Natural Science Funds of China (81371262)