The Experts below are selected from a list of 24081 Experts worldwide ranked by ideXlab platform
Michael H. Buonocore - One of the best experts on this subject based on the ideXlab platform.
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Posterior Cingulate cortex activation by emotional words fmri evidence from a valence decision task
Human Brain Mapping, 2003Co-Authors: Richard J. Maddock, Amy Garrett, Michael H. BuonocoreAbstract:Functional imaging studies consistently find that emotional stimuli activate the Posterior Cingulate cortex, a region that appears to have memory-related functions. However, prior imaging studies have not controlled for non-emotional stimulus features that might activate this region by engaging memory processes unrelated to emotion. This study examined whether emotional words activated the Posterior Cingulate cortex when these potentially confounding factors were controlled. Sixty-four pleasant and 64 unpleasant words were matched with neutral words on non-emotional features known to influence memory. Eight subjects underwent block-designed functional magnetic resonance imaging scans while evaluating the valence of these words. The Posterior Cingulate cortex was significantly activated bilaterally during both unpleasant and pleasant compared to neutral words. The strongest activation peak with both unpleasant and pleasant words was observed in the left subgenual Cingulate cortex. Anteromedial orbital and left inferior and middle frontal cortices were also activated by both pleasant and unpleasant words. Right amygdala and auditory cortex were activated only by unpleasant words, while left frontal pole was activated only by pleasant words. The results show that activation of the Posterior Cingulate cortex by emotional stimuli cannot be attributed to the memory-enhancing effects of non-emotional stimulus features. The findings are consistent with the suggestion that this region may mediate interactions of emotional and memory-related processes. The results also extend prior findings that evaluating emotional words consistently activates the subgenual Cingulate cortex, and suggest a means of probing this region in patients with mood disorders. Hum. Brain Mapping 18:30 - 41, 2003. © 2002 Wiley-Liss, Inc.
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Posterior Cingulate cortex activation by emotional words fmri evidence from a valence decision task
Human Brain Mapping, 2003Co-Authors: Richard J. Maddock, Amy Garrett, Michael H. BuonocoreAbstract:Functional imaging studies consistently find that emotional stimuli activate the Posterior Cingulate cortex, a region that appears to have memory-related functions. However, prior imaging studies have not controlled for non-emotional stimulus features that might activate this region by engaging memory processes unrelated to emotion. This study examined whether emotional words activated the Posterior Cingulate cortex when these potentially confounding factors were controlled. Sixty-four pleasant and 64 unpleasant words were matched with neutral words on non-emotional features known to influence memory. Eight subjects underwent block-designed functional magnetic resonance imaging scans while evaluating the valence of these words. The Posterior Cingulate cortex was significantly activated bilaterally during both unpleasant and pleasant compared to neutral words. The strongest activation peak with both unpleasant and pleasant words was observed in the left subgenual Cingulate cortex. Anteromedial orbital and left inferior and middle frontal cortices were also activated by both pleasant and unpleasant words. Right amygdala and auditory cortex were activated only by unpleasant words, while left frontal pole was activated only by pleasant words. The results show that activation of the Posterior Cingulate cortex by emotional stimuli cannot be attributed to the memory-enhancing effects of non-emotional stimulus features. The findings are consistent with the suggestion that this region may mediate interactions of emotional and memory-related processes. The results also extend prior findings that evaluating emotional words consistently activates the subgenual Cingulate cortex, and suggest a means of probing this region in patients with mood disorders.
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Remembering familiar people: the Posterior Cingulate cortex and autobiographical memory retrieval.
Neuroscience, 2001Co-Authors: Richard J. Maddock, Amy Garrett, Michael H. BuonocoreAbstract:Most functional imaging studies of memory retrieval investigate memory for standardized laboratory stimuli. However, naturally acquired autobiographical memories differ from memories of standardized stimuli in important ways. Neuroimaging studies of natural memories may reveal distinctive patterns of brain activation and may have particular value in assessing clinical disorders of memory. This study used functional magnetic resonance imaging to investigate brain activation during successful retrieval of autobiographical memories elicited by name-cued recall of family members and friends. The caudal part of the left Posterior Cingulate cortex was the most strongly activated region and was significantly activated in all eight subjects studied. Most subjects also showed significant activation of the left anterior orbitomedial, anterior middle frontal, precuneus, cuneus, and Posterior inferior parietal cortices, and the right Posterior Cingulate and motor cortices.Our findings are consistent with prior studies showing Posterior Cingulate cortex activation during autobiographical memory retrieval. This region is also consistently activated during retrieval of standardized memory stimuli when experimental designs emphasizing successful retrieval are employed. Our results support the hypothesis that the Posterior Cingulate cortex plays an important role in successful memory retrieval. The Posterior Cingulate cortex has strong reciprocal connections with entorhinal and parahippocampal cortices. Studies of early Alzheimer's disease, temporal lobectomy, and hypoxic amnesia show that hypometabolism of the Posterior Cingulate cortex is an early and prominent indicator of pathology in these patients. Our findings suggest that autobiographical memory retrieval tasks could be used to probe the functional status of the Posterior Cingulate cortex in patients with early Alzheimer's disease or at risk for that condition.
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activation of left Posterior Cingulate gyrus by the auditory presentation ofthreat related words an fmri study
Psychiatry Research-neuroimaging, 1997Co-Authors: Richard J. Maddock, Michael H. BuonocoreAbstract:This study investigated the cortical response to hearing threat-related and neutral words using functional magnetic resonance imaging (fMRI) in 16 coronal planes. Right-handed volunteers listened to (i) neutral words alternating with no words as the control condition, and (ii) neutral words alternating with threat-related words as the experimental condition. Threat-related words compared to neutral words activated left Posterior Cingulate gyrus in eight of 10 subjects with activation most prominent in the retrosplenial region. Patterns of activation produced by neutral words compared to no words included bilateral temporal and frontal regions but not Posterior Cingulate. The retrosplenial Cingulate region has recently been implicated in episodic memory processes. We discuss the possible role of the Posterior Cingulate cortex in processes involving emotion and memory and in anxiety disorders.
Michael L Platt - One of the best experts on this subject based on the ideXlab platform.
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neuronal activity in the Posterior Cingulate cortex signals environmental information and predicts behavioral variability during trapline foraging
The Journal of Neuroscience, 2021Co-Authors: David L Barack, Michael L PlattAbstract:Animals engage in routine behavior in order to efficiently navigate their environments. This routine behavior may be influenced by the state of the environment, such as the location and size of rewards. The neural circuits tracking environmental information and how that information impacts decisions to deviate from routines remains unexplored. To investigate the representation of environmental information during routine foraging, we recorded the activity of single neurons in Posterior Cingulate cortex (PCC) in two male monkeys searching through an array of targets in which the location of rewards was unknown. Outside the laboratory, people and animals solve such traveling salesman problems by following routine traplines that connect nearest-neighbor locations. In our task, monkeys also deployed traplining routines, but as the environment became better known, they deviate from them despite the reduction in foraging efficiency. While foraging, PCC neurons tracked environmental information but not reward and predicted variability in the pattern of choices. Together, these findings suggest that PCC may mediate the influence of information on variability in choice behavior. Significance statement Many animals seek information to better guide their decisions and update behavioral routines. In our study, subjects visually searched through a set of targets on every trial to gather two rewards. Greater amounts of information about the distribution of rewards predicted less variability in choice patterns, whereas smaller amounts predicted greater variability. We recorded from the Posterior Cingulate cortex, an area implicated in the coding of reward and uncertainty, and discovered that these neurons signaled the expected information about the distribution of rewards instead of signaling expected rewards. The activity in these cells also predicted the amount of variability in choice behavior. These findings suggest that the Posterior Cingulate helps direct the search for information in order to augment routines.
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neuronal activity in the Posterior Cingulate cortex signals environmental information and predicts behavioral variability during routine foraging
bioRxiv, 2018Co-Authors: Michael L Platt, David L BarackAbstract:Abstract Animals engage in routine behavior in order to efficiently navigate their environments. This routine behavior may be influenced by the state of the environment, such as the location and size of rewards. The neural circuits tracking environmental information and how that information impacts decisions to diverge from routines remains unexplored. To investigate the representation of environmental information during routine foraging, we recorded the activity of single neurons in Posterior Cingulate cortex (PCC) in monkeys searching through an array of targets in which the location of rewards was unknown. Outside the laboratory, people and animals solve such traveling salesman problems by following routine traplines that connect nearest-neighbor locations. In our task, monkeys also deployed traplining routines, but as the environment became better known, they diverged from them despite the reduction in foraging efficiency. While foraging, PCC neurons tracked environmental information but not reward and predicted variability in the pattern of choices. Together, these findings suggest that PCC mediates the influence of information on variability in choice behavior.
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Posterior Cingulate neurons dynamically signal decisions to disengage during foraging
Neuron, 2017Co-Authors: David L Barack, Steve W C Chang, Michael L PlattAbstract:Foraging for resources is a fundamental behavior balancing systematic search and strategic disengagement. The foraging behavior of primates is especially complex and requires long-term memory, value comparison, strategic planning, and decision-making. Here we provide evidence from two different foraging tasks that neurons in primate Posterior Cingulate cortex (PCC) signal decision salience during foraging to motivate disengagement from the current strategy. In our foraging tasks, salience refers to the difference between decision thresholds and the net harvested reward. Salience signals were stronger in poor foraging contexts than rich ones, suggesting low harvest rates recruit mechanisms in PCC that regulate strategic disengagement and exploration during foraging.
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causal evidence of performance monitoring by neurons in Posterior Cingulate cortex during learning
Neuron, 2013Co-Authors: Sarah R Heilbronner, Michael L PlattAbstract:The Posterior Cingulate cortex (CGp) is a major hub of the default mode network (DMN), a set of cortical areas with high resting activity that declines during task performance. This relationship suggests that DMN activity contributes to mental processes that are antagonistic to performance. Alternatively, DMN may detect conditions under which performance is poor and marshal cognitive resources for improvement. To test this idea, we recorded activity of CGp neurons in monkeys performing a learning task while varying reward size and novelty. We found that CGp neurons responded to errors, and this activity was magnified by small reward and novel stimuli. Inactivating CGp with muscimol impaired new learning when rewards were small but had no effect when rewards were large; inactivation did not affect performance on well-learned associations. Thus, CGp, and by extension the DMN, may support learning, and possibly other cognitive processes, by monitoring performance and motivating exploration.
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decision salience signals in Posterior Cingulate cortex
Frontiers in Neuroscience, 2011Co-Authors: Sarah R Heilbronner, Benjamin Y Hayden, Michael L PlattAbstract:Despite its phylogenetic antiquity and clinical importance, the Posterior Cingulate cortex (CGp) remains an enigmatic nexus of attention, memory, motivation, and decision making. Here we show that CGp neurons track decision salience—the degree to which an option differs from a standard—but not the subjective value of a decision. To do this, we recorded the spiking activity of CGp neurons in monkeys choosing between options varying in reward-related risk, delay to reward, and social outcomes, each of which varied in level of decision salience. Firing rates were higher when monkeys chose the risky option, consistent with their risk-seeking preferences, but were also higher when monkeys chose the delayed and social options, contradicting their preferences. Thus, across decision contexts, neuronal activity was uncorrelated with how much monkeys valued a given option, as inferred from choice. Instead, neuronal activity signaled the deviation of the chosen option from the standard, independently of how it differed. The observed decision salience signals suggest a role for CGp in the flexible allocation of neural resources to motivationally significant information, akin to the role of attention in selective processing of sensory inputs.
Richard J. Maddock - One of the best experts on this subject based on the ideXlab platform.
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Posterior Cingulate cortex activation by emotional words fmri evidence from a valence decision task
Human Brain Mapping, 2003Co-Authors: Richard J. Maddock, Amy Garrett, Michael H. BuonocoreAbstract:Functional imaging studies consistently find that emotional stimuli activate the Posterior Cingulate cortex, a region that appears to have memory-related functions. However, prior imaging studies have not controlled for non-emotional stimulus features that might activate this region by engaging memory processes unrelated to emotion. This study examined whether emotional words activated the Posterior Cingulate cortex when these potentially confounding factors were controlled. Sixty-four pleasant and 64 unpleasant words were matched with neutral words on non-emotional features known to influence memory. Eight subjects underwent block-designed functional magnetic resonance imaging scans while evaluating the valence of these words. The Posterior Cingulate cortex was significantly activated bilaterally during both unpleasant and pleasant compared to neutral words. The strongest activation peak with both unpleasant and pleasant words was observed in the left subgenual Cingulate cortex. Anteromedial orbital and left inferior and middle frontal cortices were also activated by both pleasant and unpleasant words. Right amygdala and auditory cortex were activated only by unpleasant words, while left frontal pole was activated only by pleasant words. The results show that activation of the Posterior Cingulate cortex by emotional stimuli cannot be attributed to the memory-enhancing effects of non-emotional stimulus features. The findings are consistent with the suggestion that this region may mediate interactions of emotional and memory-related processes. The results also extend prior findings that evaluating emotional words consistently activates the subgenual Cingulate cortex, and suggest a means of probing this region in patients with mood disorders. Hum. Brain Mapping 18:30 - 41, 2003. © 2002 Wiley-Liss, Inc.
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Posterior Cingulate cortex activation by emotional words fmri evidence from a valence decision task
Human Brain Mapping, 2003Co-Authors: Richard J. Maddock, Amy Garrett, Michael H. BuonocoreAbstract:Functional imaging studies consistently find that emotional stimuli activate the Posterior Cingulate cortex, a region that appears to have memory-related functions. However, prior imaging studies have not controlled for non-emotional stimulus features that might activate this region by engaging memory processes unrelated to emotion. This study examined whether emotional words activated the Posterior Cingulate cortex when these potentially confounding factors were controlled. Sixty-four pleasant and 64 unpleasant words were matched with neutral words on non-emotional features known to influence memory. Eight subjects underwent block-designed functional magnetic resonance imaging scans while evaluating the valence of these words. The Posterior Cingulate cortex was significantly activated bilaterally during both unpleasant and pleasant compared to neutral words. The strongest activation peak with both unpleasant and pleasant words was observed in the left subgenual Cingulate cortex. Anteromedial orbital and left inferior and middle frontal cortices were also activated by both pleasant and unpleasant words. Right amygdala and auditory cortex were activated only by unpleasant words, while left frontal pole was activated only by pleasant words. The results show that activation of the Posterior Cingulate cortex by emotional stimuli cannot be attributed to the memory-enhancing effects of non-emotional stimulus features. The findings are consistent with the suggestion that this region may mediate interactions of emotional and memory-related processes. The results also extend prior findings that evaluating emotional words consistently activates the subgenual Cingulate cortex, and suggest a means of probing this region in patients with mood disorders.
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Remembering familiar people: the Posterior Cingulate cortex and autobiographical memory retrieval.
Neuroscience, 2001Co-Authors: Richard J. Maddock, Amy Garrett, Michael H. BuonocoreAbstract:Most functional imaging studies of memory retrieval investigate memory for standardized laboratory stimuli. However, naturally acquired autobiographical memories differ from memories of standardized stimuli in important ways. Neuroimaging studies of natural memories may reveal distinctive patterns of brain activation and may have particular value in assessing clinical disorders of memory. This study used functional magnetic resonance imaging to investigate brain activation during successful retrieval of autobiographical memories elicited by name-cued recall of family members and friends. The caudal part of the left Posterior Cingulate cortex was the most strongly activated region and was significantly activated in all eight subjects studied. Most subjects also showed significant activation of the left anterior orbitomedial, anterior middle frontal, precuneus, cuneus, and Posterior inferior parietal cortices, and the right Posterior Cingulate and motor cortices.Our findings are consistent with prior studies showing Posterior Cingulate cortex activation during autobiographical memory retrieval. This region is also consistently activated during retrieval of standardized memory stimuli when experimental designs emphasizing successful retrieval are employed. Our results support the hypothesis that the Posterior Cingulate cortex plays an important role in successful memory retrieval. The Posterior Cingulate cortex has strong reciprocal connections with entorhinal and parahippocampal cortices. Studies of early Alzheimer's disease, temporal lobectomy, and hypoxic amnesia show that hypometabolism of the Posterior Cingulate cortex is an early and prominent indicator of pathology in these patients. Our findings suggest that autobiographical memory retrieval tasks could be used to probe the functional status of the Posterior Cingulate cortex in patients with early Alzheimer's disease or at risk for that condition.
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activation of left Posterior Cingulate gyrus by the auditory presentation ofthreat related words an fmri study
Psychiatry Research-neuroimaging, 1997Co-Authors: Richard J. Maddock, Michael H. BuonocoreAbstract:This study investigated the cortical response to hearing threat-related and neutral words using functional magnetic resonance imaging (fMRI) in 16 coronal planes. Right-handed volunteers listened to (i) neutral words alternating with no words as the control condition, and (ii) neutral words alternating with threat-related words as the experimental condition. Threat-related words compared to neutral words activated left Posterior Cingulate gyrus in eight of 10 subjects with activation most prominent in the retrosplenial region. Patterns of activation produced by neutral words compared to no words included bilateral temporal and frontal regions but not Posterior Cingulate. The retrosplenial Cingulate region has recently been implicated in episodic memory processes. We discuss the possible role of the Posterior Cingulate cortex in processes involving emotion and memory and in anxiety disorders.
Winnie S Liang - One of the best experts on this subject based on the ideXlab platform.
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circular rna expression and regulatory network prediction in Posterior Cingulate astrocytes in elderly subjects
BMC Genomics, 2018Co-Authors: Winnie S Liang, Shobana Sekar, Lori Cuyugan, Jonathan Adkins, Philipp GeigerAbstract:Circular RNAs (circRNAs) are a novel class of endogenous, non-coding RNAs that form covalently closed continuous loops and that are both highly conserved and abundant in the mammalian brain. A role for circRNAs in sponging microRNAs (miRNAs) has been proposed, but the circRNA-miRNA-mRNA interaction networks in human brain cells have not been defined. Therefore, we identified circRNAs in RNA sequencing data previously generated from astrocytes microdissected from the Posterior Cingulate (PC) of Alzheimer’s disease (AD) patients (N = 10) and healthy elderly controls (N = 10) using four circRNA prediction algorithms - CIRI, CIRCexplorer, find_circ and KNIFE. Overall, utilizing these four tools, we identified a union of 4438 unique circRNAs across all samples, of which 70.3% were derived from exonic regions. Notably, the widely reported CDR1as circRNA was detected in all samples across both groups by find_circ. Given the putative miRNA regulatory function of circRNAs, we identified potential miRNA targets of circRNAs, and further, delineated circRNA-miRNA-mRNA networks using in silico methods. Pathway analysis of the genes regulated by these miRNAs identified significantly enriched immune response pathways, which is consistent with the known function of astrocytes as immune sensors in the brain. In this study, we performed circRNA detection on cell-specific transcriptomic data and identified potential circRNA-miRNA-mRNA regulatory networks in PC astrocytes. Given the known function of astrocytes in cerebral innate immunity and our identification of significantly enriched immune response pathways, the circRNAs we identified may be associated with such key functions. While we did not detect recurrent differentially expressed circRNAs in the context of healthy controls or AD, we report for the first time circRNAs and their potential regulatory impact in a cell-specific and region-specific manner in aged subjects. These predicted regulatory network and pathway analyses may help provide new insights into transcriptional regulation in the brain.
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circular rna expression and regulatory network prediction in Posterior Cingulate astrocytes in elderly subjects
bioRxiv, 2018Co-Authors: Shobana Sekar, Lori Cuyugan, Jonathan Adkins, Philipp Geiger, Winnie S LiangAbstract:Background: Circular RNAs (circRNAs) are a novel class of endogenous, non-coding RNAs that form covalently closed continuous loops and are both highly conserved and abundant in the mammalian brain. A role for circRNAs in sponging microRNAs (miRNAs) has been proposed, but the circRNA-miRNA-mRNA interaction networks in human brain cells have not been defined. Therefore, we identified circRNAs in RNA sequencing data previously generated from astrocytes microdissected from the Posterior Cingulate (PC) of Alzheimer′s disease (AD) patients (N=10) and healthy elderly controls (N=10) using four circRNA prediction algorithms - CIRI, CIRCexplorer, find_circ and KNIFE. Results: Overall, utilizing these four tools, we identified a union of 4,438 unique circRNAs across all samples, of which 70.3% were derived from exonic regions. Notably, the widely reported CDR1as circRNA was detected in all samples across both groups by find_circ. Given the putative miRNA regulatory function of circRNAs, we identified potential miRNA targets of circRNAs, and further, delineated circRNA-miRNA-mRNA networks using in silico methods. Pathway analysis of the genes regulated by these miRNAs identified significantly enriched immune response pathways, which is consistent with the known function of astrocytes as immune sensors in the brain. Conclusions: In this study, we performed circRNA detection on cell-specific transcriptomic data and identified potential circRNA-miRNA-mRNA regulatory networks in PC astrocytes. Given the known function of astrocytes in cerebral innate immunity and our identification of significantly enriched immune response pathways, the circRNAs we identified may be associated with such key functions. While we did not detect recurrent differentially expressed circRNAs in the context of healthy controls or Alzheimer′s, we report for the first time circRNAs and their potential regulatory impact in a cell-specific and region-specific manner in aged subjects. These predicted regulatory network and pathway analyses may help provide new insights into transcriptional regulation in the brain.
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alzheimer s disease is associated with reduced expression of energy metabolism genes in Posterior Cingulate neurons
Proceedings of the National Academy of Sciences of the United States of America, 2008Co-Authors: Winnie S Liang, Jon Valla, Thomas G Beach, Eric M Reiman, Travis Dunckley, Andrew Grover, Tracey L Niedzielko, Lonnie Schneider, Diego Mastroeni, Richard J CaselliAbstract:Alzheimer's disease (AD) is associated with regional reductions in fluorodeoxyglucose positron emission tomography (FDG PET) measurements of the cerebral metabolic rate for glucose, which may begin long before the onset of histopathological or clinical features, especially in carriers of a common AD susceptibility gene. Molecular evaluation of cells from metabolically affected brain regions could provide new information about the pathogenesis of AD and new targets at which to aim disease-slowing and prevention therapies. Data from a genome-wide transcriptomic study were used to compare the expression of 80 metabolically relevant nuclear genes from laser-capture microdissected non-tangle-bearing neurons from autopsy brains of AD cases and normal controls in Posterior Cingulate cortex, which is metabolically affected in the earliest stages; other brain regions metabolically affected in PET studies of AD or normal aging; and visual cortex, which is relatively spared. Compared with controls, AD cases had significantly lower expression of 70% of the nuclear genes encoding subunits of the mitochondrial electron transport chain in Posterior Cingulate cortex, 65% of those in the middle temporal gyrus, 61% of those in hippocampal CA1, 23% of those in entorhinal cortex, 16% of those in visual cortex, and 5% of those in the superior frontal gyrus. Western blots confirmed underexpression of those complex I–V subunits assessed at the protein level. Cerebral metabolic rate for glucose abnormalities in FDG PET studies of AD may be associated with reduced neuronal expression of nuclear genes encoding subunits of the mitochondrial electron transport chain.
Guillaume Marrelec - One of the best experts on this subject based on the ideXlab platform.
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the precuneus Posterior Cingulate cortex plays a pivotal role in the default mode network evidence from a partial correlation network analysis
NeuroImage, 2008Co-Authors: Peter Fransson, Guillaume MarrelecAbstract:Abstract Recent research has shown that intrinsic brain activity as observed by functional magnetic resonance imaging (fMRI) manifest itself as coherent signal changes in networks encompassing brain regions that span long-range neuronal pathways. One of these networks, the so called default mode network, has become the primary target in recent investigations to link intrinsic activity to cognition and how intrinsic signal changes may be altered in disease. In this study we assessed functional connectivity within the default mode network during both rest and a continuous working memory task on a region-by-region basis using partial correlation analysis, a data-driven method that provides insight into effective connectivity within neuronal networks. Prominent features of functional connectivity within the default mode network included an overall strong level of interaction between the precuneus/Posterior Cingulate region and the rest of the default mode network, as well as a high degree of interaction between the left and right medial temporal lobes combined with weak interactions between the medial temporal lobes and the rest of the default mode network. Additionally, we found support for strong interactions between the precuneus/Posterior Cingulate cortex and the left inferior parietal lobe as well as between the dorsal and ventral sections of the medial prefrontal cortex. The suggested pivotal role of the precuneus/Posterior Cingulate cortex in the default mode network is discussed.