Cingulate Region (cingulate + region)

Distribution by Scientific Domains


Selected Abstracts


Does the cingulate cortex contribute to spatial conditional associative learning in the rat?

HIPPOCAMPUS, Issue 7 2009
Marie St-Laurent
Abstract Rats with lesions to the anterior or posterior (retrosplenial) region of the cingulate cortex and rats with lesions that included both the anterior and posterior cingulate cortex were tested on a visual,spatial conditional task in which they had to learn to approach one of the two objects depending on the spatial context within which they were embedded. Lesions restricted to either the anterior or the retrosplenial cingulate region did not impair learning of this task which is known to be very sensitive to the effects of hippocampal lesions. Complete lesions of the cingulate cortex gave rise to only a minor retardation in learning. In contrast, lesions to the retrosplenial cortex impaired performance on a spatial navigation task and the classic radial maze. These results suggest that the retrosplenial portion of the cingulate region forms part of a hippocampal circuit underlying learning about spatial responses. The dissociation between the effects of lesions of the cingulate region on different classes of behavior known to be associated with hippocampal function suggests that, although this neural structure does play a role in an extended hippocampal circuit underlying spatial learning, its role in such learning may be a selective one. © 2009 Wiley-Liss, Inc. [source]


Posterior cingulate activation during moral dilemma in adolescents

HUMAN BRAIN MAPPING, Issue 8 2008
Jesus Pujol
Abstract Neuroimaging research examining correlates of adolescent behavioral maturation has focused largely on issues related to higher cognitive development. Currently few studies have explored neural correlates of emotional reactivity in adolescent groups. In this study, we sought to examine the nature of posterior cingulate activation during situations of moral dilemma in normal adolescents. We focused on this region because of emerging evidence that suggests its role in emotionally self-relevant mental processing. Ten healthy teenagers, aged from 14 to 16 years, underwent three fMRI sequences designed to examine (i) brain responses during moral dilemma; (ii) brain responses during passive viewing of the moral dilemma outcome; and (iii); "deactivation" during a simple cognitive task compared with resting-state activity. Our main finding was that during moral dilemma, all subjects showed significant activation of the posterior cingulate cortex, and more variable activation of the medial frontal cortex and angular gyrus. Interestingly, these findings were replicated in each subject using the passive viewing task, suggesting that the previous pattern was not specific to moral reasoning or decision making. Finally, six of the ten subjects showed deactivation of the same posterior cingulate region during the cognitive task, indicating some commonality of function between posterior cingulate activity during moral dilemmas and rest. We propose that these posterior cingulate changes may relate to basic neuronal activities associated with processing self-relevant emotional stimuli. Given the high single-subject reproducibility of posterior cingulate activations, our findings may contribute to further characterize adolescent emotional reactivity in developmental neuroimaging studies. Hum Brain Mapp, 2008. © 2007 Wiley-Liss, Inc. [source]


Adding another spectral dimension to 1H magnetic resonance spectroscopy of hepatic encephalopathy,

JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2005
Nader Binesh PhD
Abstract Purpose To evaluate a localized two-dimensional correlated magnetic resonance spectroscopic (L-COSY) technique in patients with hepatic encephalopathy (HE) and healthy subjects, and to correlate the cerebral metabolite changes with neuropsychological (NP) test scores. Materials and Methods Eighteen minimal hepatic encephalopathy (MHE) patients and 21 healthy controls have been investigated. A GE 1.5-T magnetic resonance (MR) scanner was used in combination with a body MR coil for transmission and a 3-inch surface coil for reception. A 27-mL voxel was localized by three slice-selective radio frequency (RF) pulses (90°-180°-90°) in the anterior cingulate region. The total duration of each two-dimensional L-COSY spectrum was approximately 25 minutes. The NP battery included a total of 15 tests, which were grouped into six domains. Results MR spectroscopic results showed a statistically significant decrease in myo-inositol (mI) and choline (Ch) and an increase in glutamate/glutamine (Glx) in patients when compared to healthy controls. There was also an increase in taurine (Tau) in patients. The NP results indicated a significant correlation between motor function assessed by NP tests and mI ratios recorded using two-dimensional L-COSY. Conclusion The study demonstrated the feasibility of evaluating the two-dimensional L-COSY sequence in a clinical environment. The results showed additional cerebral metabolites that can be measured with the technique in comparison to one-dimensional study. J. Magn. Reson. Imaging 2005;21:398,405. © 2005 Wiley-Liss, Inc. [source]