ABSTRACT
Objective To explore the impact of the variable number of tandem repeats of monoamine oxidase A gene (MAOA-uVNTR) on the concentration of gray matter in patients with major depressive disorders.Methods 56 cases of depression, as well as 37 healthy controls who were matched in gender, age and years of education were divided into low-activity genotype (3R or 3R/4R), and high-activity genotype (4R) with the methods of polymerase chain reaction (PCR) amplification and 1.5％ agarose gel electrophoresis separation. 93 cases all were performaned structural magnetic resonance imaging scanning. Results ① The difference of genotype and allele frequency between the depression group and the healthy group was not statistically significant(P＞0.05 ). ②Compared with the healthy,the concentration of gray matter( GMC ) of bilateral caudate nucleus (K = 11/68, Z =3.76/4.76 ), bilateral thalamus ( K = 21/181, Z = 3.26/3.63 ) and right hypothalamus ( K = 38/12, Z = 4.20/3.60) reduced significantly in depressed patients. ③ In patients with depression, cases with the high-activity genotype showed reduced GMC bilateral caudate nucleus (K = 17/33, Z = 3.23/4.36 ), left putamen ( K = 16, Z =3.42 ) and right hypothalamus( K = 12, Z = 3.62 ) in comparision with patients with low-activity genotype. In highactivity genotype group,compared with the healthy,patients with depression had reduced GMC in left caudate nucleus ( K = 11, Z = 4.13 ), bilateral thalamus ( K = 13/14, Z = 3.53/3.23 ) and left parahippocampal gyrus ( K = 13,Z = 4.04). Conclusion High-activity genotype may be an important factor contributing to the structural abnormalitily of the limbic-striatum-globus pallidus-thalamus loop.
ABSTRACT
OBJECTIVE: To identify changes in gray and white matter concentrations (GMC, WMC), and their relation to heterotopic neuron numbers in mesial temporal lobe epilepsy (mTLE). MATERIALS AND METHODS: The gray matter or white matter concentrations of 16 left and 15 right mTLE patients who achieved an excellent surgical outcome were compared with those of 24 healthy volunteers for the left group and with 23 healthy volunteers for the right group, by optimized voxel-based morphometry using unmodulated and modulated images. A histologic count of heterotopic neurons was obtained in the white matter of the anterior temporal lobe originating from the patients' surgical specimens. In addition, the number of heterotopic neurons were tested to determine if there was a correlation with the GMC or WMC. RESULTS: The GMCs of the left and right mTLE groups were reduced in the ipsilateral hippocampi, bilateral thalami, precentral gyri, and in the cerebellum. The WMCs were reduced in the ipsilateral white matter of the anterior temporal lobe, bilateral parahippocampal gyri, and internal capsules, but increased in the pons and bilateral precentral gyri. The heterotopic neuron counts in the left mTLE group showed a positive correlation (r = 0.819, p < 0.0001) with GMCs and a negative correlation (r = -0.839, p < 0.0001) with WMCs in the white matter of the anterior temporal lobe. CONCLUSION: The present study shows the abnormalities of the cortico-thalamo-hippocampal network including a gray matter volume reduction in the anterior frontal lobes and an abnormality of brain tissue concentration in the pontine area. Furthermore, heterotopic neuron numbers were significantly correlated with GMC or WMC in the left white matter of anterior temporal lobe.