Journal of neuroscience methods
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J. Neurosci. Methods · Sep 2008
Blocking pterygopalatine arterial blood flow decreases infarct volume variability in a mouse model of intraluminal suture middle cerebral artery occlusion.
The mouse model of intraluminal suture middle cerebral artery occlusion (MCAO) is still associated with several issues, such as variability of infarction volume and survival. Thus, the method is far from standardization. The effect of blood flow in the pterygopalatine artery (PPA) in the mouse MCAO model remains obscure. ⋯ Although mean infarct volume did not obviously differ between the MCAO-U and other two groups, infarct volumes varied significantly more within the MCAO-U, than in the other two groups (p<0.05). We concluded that collateral circulation from the PPA to the brain significantly influences the MCAO model, and cannot be ignored. An approximately consistent mouse MCAO model can be generated using commercially available silicone-coated sutures while blocking PPA blood flow during occlusion.
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J. Neurosci. Methods · Aug 2008
CatWalk gait analysis in assessment of functional recovery after sciatic nerve injury.
Following peripheral nerve injury repair, improved behavioural outcome may be the most important evidence of functionality of axon regeneration after any repair strategy. A range of behavioural testing paradigms have been developed for peripheral nerve injury research. Complete injury of the adult rat sciatic nerve is frequently used in combination with walking track analysis. ⋯ Using the sciatic nerve crush injury model (validated with the static sciatic index) and a follow-up period of 12 weeks, we now show that CatWalk can also measure behavioural recovery. In particular dynamic gait parameters, coordination measures, and the intensity of paw prints are of interest in detecting recovery as far as these parameters completely return to pre-operative values after crush injury. We conclude that CatWalk can be used as a complementary approach to other behavioural testing paradigms to assess clinically relevant behavioural benefits, with a main advantage that CatWalk demonstrates both static and dynamic gait parameters at the same time.
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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.