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Object: The purpose of our study was to investigate the microstructural changes of the medial temporal cortex in mild cognitive impairment (MCI) patients with cerebral small vascular disease (cSVD) using diffusion kurtosis imaging (DKI) and to examine whether DKI parameters are correlated with MCI.Method: A total of 82 cSVD patients admitted to the Department of Neurology Beijing Chaoyang Hospital, Capital Medical University, were retrospectively enrolled in this study. The Montreal cognitive assessment scale (MoCA) score was used to assess overall cognitive function. According to the presence or absence of MCI, these patients were divided into an MCI group (n = 48) and a non-MCI group (n = 34). The general clinical data of the two groups were collected and analyzed. The regions of interest (ROIs) in the medial temporal cortex were selected for investigation. The averaged values of DKI parameters were measured in each ROI and compared between the two groups, and the correlations between DKI parameters and MoCA score and between diffusion and kurtosis parameters were examined.Results: Compared to the non-MCI group, MCI patients showed significantly increased mean diffusion (MD) and radial diffusion (RD) and significantly decreased mean kurtosis (MK) in the left hippocampus (P = 0.005, 0.006, 0.002, respectively). In the left hippocampus, fractional anisotropy (FA), MK, radial kurtosis (RK), and kurtosis fractional anisotropy (KFA) showed significantly positive correlations with MoCA score (r = 0.374, 0.37, 0.392, 0.242, respectively, all P < 0.05), while MK and RD were negatively correlated with MoCA score (r = −0.227, −0.255, respectively, both P < 0.05). In the left parahippocampal region, axial kurtosis (AK) and KFA were positively correlated with MoCA score (r = 0.228, 0.282, respectively, both P < 0.05), while RK was positively correlated with MoCA score in the right parahippocampal region (r = 0.231, P < 0.05). Significant correlations of MD with MK, RD with RK, and FA with KFA were observed in the medial temporal cortex (r = −0.254, −0.395, 0.807, respectively, all P < 0.05) but not of axial diffusion (AD) with AK.Conclusion: The DKI technique can be used to observe microstructural changes of the medial temporal cortex in MCI patients with cSVD. The DKI-derived parameters might be a feasible means of evaluating patients with MCI.

Objective: Synaptic vesicles (SVs) are essential organelles that store and release neurotransmitters within presynaptic terminals. Isolated and purified SVs can be used to investigate their biochemical, structural, and functional characteristics, to elucidate the neurotransmission process. This paper describes a method for obtaining purified and functional SVs. Methods: SVs were isolated from the brains of Sprague--Dawley rats using differential and density-gradient centrifugation. Their morphology was observed with electron microscopy. The amount of protein in the SV fraction was determined by the Bradford assay. Specific SVs were purified using magnetic beads and immunoisolation, and immunoblot assays were used to measure levels of SV markers. SV glutamate uptake was assayed by radiotracer efflux assays. Results: A total of 10 mg SV protein was purified from 22 g of hippocampal and cerebral cortex tissue. The purified SVs were homogenous small spherical vesicles with a diameter of ~40 nm as assessed with electron microscopy, and they were rich in the protein SV protein 2 (SV2), vesicular glutamate transporter 1 (VGLUT1), and VGLUT2, but not VGLUT3. The SV2-specific SVs obtained by immunoadsorption with nearly 83% yield could uptake L- glutamate. Rose Bengal, a VGLUT inhibitor, prevented SV2-specific SVs from taking-up L- glutamate. Conclusions: This study describes a successful method for obtaining purified SVs that retained their structure and ability to perform their primary in vivo functions. These SVs can be used to understand SV composition and function, and the process of neurotransmitter release, and to evaluate therapeutic drugs for nervous system diseases. [ABSTRACT FROM AUTHOR]