Journal of neuroscience methods
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J. Neurosci. Methods · Jul 2008
Early behavioral and histological outcomes following a novel traumatic partial nerve lesion.
A new partial nerve lesion (PNL) model is needed to better simulate traumatic lesions seen clinically that result in both dysfunction and neuropathic pain. We assessed surgical variability and several outcome measures including histology during the acute postoperative period. A surgical lesion was created in the rat tibial nerve by removing a segment, later confirmed by myelinated axon counts. ⋯ Replicated experiments confirmed the PMD, muscle atrophy, and formation of neuropathic pain. In conclusion, our partial lesion histologically progresses twofold during the first postoperative week with profound behavioral deficits involving both motor and sensory loss. These results based on sensitive and correlative outcome measures support the application of this novel model in experimental nerve lesion studies.
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J. Neurosci. Methods · Jul 2008
Characterizing regional correlation, laterality and symmetry of amyloid deposition in mild cognitive impairment and Alzheimer's disease with Pittsburgh Compound B.
We evaluated the region-to-region correlation, laterality and asymmetry of amyloid deposition in subjects with mild cognitive impairment (MCI) or Alzheimer's disease (AD) using the amyloid tracer, Pittsburgh Compound B (PiB). Seventeen subjects, including 7 with MCI (MMSE 26.7+/-2.4) and 10 with AD (MMSE of 24.8+/-2.7) underwent PiB imaging. Measures of laterality (i.e., group-wise predilection for right or left) and asymmetry (i.e., group-wise predilection for unequal PiB retention between the two hemispheres) were calculated for 17 Regions of Interest (ROIs). ⋯ Overall, PiB retention was symmetric bilaterally, but there was PiB laterality in MCI in dorsal frontal cortex [(t(6)=3.05, p=0.02, L>R] and sensory-motor area [t(6)=3.10, p=0.02, L>R] and in AD in the occipital pole (t(9)=-2.63, p=0.03, R>L). The most significant asymmetries in PiB retention were found in sub-cortical white matter (t(6)=3.99, p=0.01) and middle precuneus [(t(6)=3.57, p=0.01] in MCI, and in lateral temporal cortex (t(9)=3.02, p=0.01) and anterior ventral striatum [t(9)=2.37, p=0.04] in AD. No group differences (AD versus MCI) were detected in laterality [F (1, 15)=0.15, p=0.7] or asymmetry [F (1, 15)=0.7, p=0.42].
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J. Neurosci. Methods · Jul 2008
Long-range correlation of renal sympathetic nerve activity in both conscious and anesthetized rats.
In this study we employed both detrended fluctuation analysis (DFA) and multiscale entropy (MSE) measurements to compare the long-range temporal correlation (LRTC) of multifibre renal sympathetic nerve activity (RSNA) between conscious and anesthetized Wistar rats. It was found that both methods showed the obvious LRTC properties in conscious state. Moreover, the scaling exponent of the RSNA in conscious rats was significantly higher than that in anesthetized rats. ⋯ This suggests that the fractal properties of underlying dynamics of the system have been reduced by anesthesia. The results demonstrate that apparently random fluctuations in multifibre RSNA are dictated by a complex deterministic process that imparts "long-term" memory to the dynamic system. However, this memory is significantly weakened by anesthesia.