Diffusion-tensor imaging can be used to observe the microstructure of brain tissue. Fractional sotropy reflects the integrity of white matter fibers. Fractional anisotropy of a young adult brain is low in gray matter, high in white matter, and highest in the splenium of the corpus cal osum. Thus, we selected the anterior and posterior limbs of the internal capsule, head of the caudate nucleus, se-mioval center, thalamus, and corpus cal osum (splenium and genu) as regions of interest when using diffusion-tensor imaging to observe fractional anisotropy of major white matter fiber tracts and the deep gray matter of healthy rhesus monkeys aged 4-8 years. Results showed no laterality ferences in fractional anisotropy values. Fractional anisotropy values were low in the head of date nucleus and thalamus in gray matter. Fractional anisotropy values were highest in the sple-nium of corpus cal osum in the white matter, fol owed by genu of the corpus cal osum and the posterior limb of the internal capsule. Fractional anisotropy values were lowest in the semioval center and posterior limb of internal capsule. These results suggest that fractional anisotropy values in major white matter fibers and the deep gray matter of 4-8-year-old rhesus monkeys are similar to those of healthy young people.

恒河猴异体椎间盘移植组织学活性和生物化学研究

Objective To investigate the histological viability and the biochemical change of fresh allografted intervertebral disc of rhesus monkey.Methods Under general anaesthesia,osteotomies of 12 rhesus monkeys were made at the endplates about 2.0 mm away from the L4～ 5 intervertibral disc,then the fresh discs were transposed in two matched monkeys. The four groups of animals were sampled after the third, sixth,ninth and twelfth month respectively.Histological viability was assessed by 3H Proline incorporation and biochemical changes were measured by water,proteoglycan and collagen content. Results Study of histological viability demonstrated that the DPM (Disintegration Per Minute) of 3H Proline increased at the third month in anulus fibrous and the sixth month in nucleous pulposus.In the nucleus pulposus of implanted disc the study of biochemistry showed that proteoglycan content was not change obviously nine months ago, but proteoglycan content decreased at the twelfth month.Collagen contents increased at the third,sixth and ninth month. Water contents were not change among twelve months. In the annulus fibrous of implanted disc,proteoglycan and water contents decreased at the ninth month, but they were increased at the twelfth month. Collagen content increased at the sixth month,but it decreased at the ninth month again. Conclusions The present results showed the intervertibral disc grafted survived allologous transplantation.The fresh allografted intervertibral disc appeared some ability of regeneration.