Abstract& These experiments use functional magnetic resonance imaging (fMRI) to reveal neural activity uniquely associated with perception of biological motion. We isolated brain areas activated during the viewing of point-light figures, then compared those areas to regions known to be involved in coherent-motion perception and kinetic-boundary perception.

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Background and aims: Irritable bowel syndrome (IBS) is a disorder of intestinal hypersensitivity and altered motility, exacerbated by stress. Functional magnetic resonance imaging (fMRI) during painful rectal distension in IBS has demonstrated greater activation of the anterior cingulate cortex (ACC), an area relevant to pain and emotions. Tricyclic antidepressants are effective for IBS. The aim of this study was to determine if low dose amitriptyline reduces ACC activation during painful rectal distension in IBS to confer clinical benefits. Secondary aims were to identify other brain regions altered by amitriptyline, and to determine if reductions in cerebral activation are greater during mental stress. Methods: Nineteen women with painful IBS were randomised to amitriptyline 50 mg or placebo for one month and then crossed over to the alternate treatment after washout. Cerebral activation during rectal distension was compared between placebo and amitriptyline groups by fMRI. Distensions were performed alternately during auditory stress and relaxing music. Results: Rectal pain induced significant activation of the perigenual ACC, right insula, and right prefrontal cortex. Amitriptyline was associated with reduced pain related cerebral activations in the perigenual ACC and the left posterior parietal cortex, but only during stress. Conclusions: The tricyclic antidepressant amitriptyline reduces brain activation during pain in the perigenual (limbic) anterior cingulated cortex and parietal association cortex. These reductions are only seen during stress. Amitriptyline is likely to work in the central nervous system rather than peripherally to blunt pain and other symptoms exacerbated by stress in IBS.

ower (amplitude) CDS has significant potential to contribute to improved understanding of tumor vascularity and blood flow in vivo. 1 However, its inability to quantitate blood flow is a major current limitation. It was the purpose of this study to devise and test a 2D and 3D a-CDS system designed to quantitate tumor vascularity and flow as they correlate with histologic determinations of vascularity. In addition, changes in flow after intravenous infusion of CM-101 were studied as a means to evaluate possible effects (within 1 h) in tumor blood flow. This exotoxin has been reported to affect tumor vascularity in our previously reported study and was used as a means to produce changes in vascularity that might be detected by 3D a-CDS. This study was designed to evaluate the accuracy of a system to quantitate tumor vascularity with amplitude (power) color Doppler sonography twoand three-dimensionally. The vascularity of 20 transplanted murine tumors was determined with quantitated amplitude color Doppler sonography both two-and three-dimensionally and compared to tumor vascularity estimated by histologic examination. Serial examinations were performed 15, 30, 45, and 60 min after the injection of the exotoxin CM-101 and saline solution to assess changes in tumor vascularity. Three-dimensional amplitude color Doppler sonography best depicted the overall vascularity of tumor when compared to histologic estimation of vessel density. However, neither twonor three-dimensional amplitude color power angiography correlated well to the microvessel count, probably a reflection of the difference in the method for vessel quantification using sonographic versus histologic techniques. Three-dimensional amplitude Doppler sonography correlated better with counts of large vessels (> 100 µm) as opposed to small vessels (> 15 µm). Time-activity curves showed no difference in tumor flow at the times measured in the experimental group injected with CM-101 or when compared to saline solutions in either the peripheral or central portions of the tumor. This three-dimensional amplitude color Doppler sonographic system affords global quantification of tumor vascularity and flow that may, in turn, be useful in determining the probability of malignancy (by determination of branching patterns and vessel regularity) or tumor response or both to treatment. KEY WORDS: Color Doppler sonography; Tumor, vascularity; Vascularity, tumor.