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Menno P Witter - One of the best experts on this subject based on the ideXlab platform.
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SPECIAL ISSUE CONTRIBUTIONS OF THALAMIC NUCLEI TO DECLARATIVE MEMORY FUNCTIONING
2015Co-Authors: D. Van, J Jolles, Menno P Witter, Der Werf, Harry B M UylingsAbstract:In spite of the acknowledged role that the thalamus plays in declarative memory, details about the precise memory processes it is involved in and which are the structures of the thalamus that contribute to these processes remain unknown. An overview is presented of human clinical and animal experimental findings showing the involvement of the thalamus, at the level of white matter tracts and separate nuclei, in aspects of memory functioning. The region in the thalamus that contributes to declarative memory is the anterior and medial division, containing the anterior nuclei, the medial dorsal Nucleus and the intralaminar and midline nuclei. A lesion to the anterior nuclei or their afferent white matter tract, the mammillothalamic tract, results in deficits of encoding of new stimuli. Lesions to the medial dorsal Nucleus affect executive processes pertaining to declarative memory, such as the use of memory strategies for retrieval; damage to the intralaminar and midline nuclei results in decreased arousal and thus affects the declarative memory process. Based on anatomical and functional data, a theory is proposed of how the thalamus might play a role at different levels of declarative memory functioning. Firstly, the anterior and Mediodorsal Nucleus ar
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neurotoxic lesions of the thalamic reuniens or Mediodorsal Nucleus in rats affect non mnemonic aspects of watermaze learning
Brain Structure & Function, 2009Co-Authors: Margriet Dollemanvan Der J Weel, Menno P Witter, Richard G M MorrisAbstract:Rats with bilateral neurotoxic reuniens (RE), Mediodorsal (MD), hippocampal (HIPP) or sham (SH) lesions were tested in a standard watermaze task, together with unoperated rats. RE-rats and SH-controls readily learned to swim directly to a hidden platform. In contrast, MD-rats displayed a transient deficit characterized initially by thigmotaxis. Like in previous studies, HIPP-rats had long latencies throughout training and displayed more random swims than the other groups. In a memory probe test with the platform removed, SH- and RE-rats approached the correct location relatively directly but, whereas SH-controls persistently searched in the training quadrant, RE-rats switched to searching all over the pool. The MD-group swam in loops to the platform, but then displayed persistent searching in the training quadrant. The HIPP-group performed at chance. These distinct patterns indicate that, although their search strategies were different, RE- and MD-rats had acquired sufficient knowledge about the platform location and could recall information in the probe test. All groups performed well in a subsequent cue test with a visible platform, with RE-rats initially escaping faster than the SH- and HIPP-groups, and MD-rats improving from an initially poorer level of performance to control level. This indicates that there were no sensorimotor or motivational deficits associated with any of the lesions. In conclusion, while the RE and MD nuclei seem not to be critical for the learning and memory of a standard watermaze task, they may contribute to non-mnemonic strategy shifting when animals are challenged in ways that do not occur during training.
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contributions of thalamic nuclei to declarative memory functioning
Cortex, 2003Co-Authors: Ysbrand D Van Der Werf, J Jolles, Menno P Witter, Harry B M UylingsAbstract:In spite of the acknowledged role that the thalamus plays in declarative memory, details about the precise memory processes it is involved in and which are the structures of the thalamus that contribute to these processes remain unknown. An overview is presented of human clinical and animal experimental findings showing the involvement of the thalamus, at the level of white matter tracts and separate nuclei, in aspects of memory functioning. The region in the thalamus that contributes to declarative memory is the anterior and medial division, containing the anterior nuclei, the medial dorsal Nucleus and the intralaminar and midline nuclei. A lesion to the anterior nuclei or their afferent white matter tract, the mammillothalamic tract, results in deficits of encoding of new stimuli. Lesions to the medial dorsal Nucleus affect executive processes pertaining to declarative memory, such as the use of memory strategies for retrieval; damage to the intralaminar and midline nuclei results in decreased arousal and thus affects the declarative memory process. Based on anatomical and functional data, a theory is proposed of how the thalamus might play a role at different levels of declarative memory functioning. Firstly, the anterior and Mediodorsal Nucleus are involved in processing the contents of the stimuli for storage and recall. The anterior nuclei influence the selection of material to be stored and remembered, whereas the Mediodorsal Nucleus is involved in the coordination and selection of the strategies used to retrieve material. Secondly, the intralaminar and midline nuclei and specifically the lateral and ventral components, maintain a necessary state of the cortical regions involved in the ongoing memory processes. The two types of function subserved by these groups of thalamic nuclei, focussing on contents vs. state, need to work in parallel to mediate and allow memory functioning, respectively.
Monte S. Buchsbaum - One of the best experts on this subject based on the ideXlab platform.
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metabolic disconnection between the Mediodorsal Nucleus of the thalamus and cortical brodmann s areas of the left hemisphere in schizophrenia
American Journal of Psychiatry, 2005Co-Authors: Serge A Mitelman, Erin A. Hazlett, William Byne, Eileen Kemether, Monte S. BuchsbaumAbstract:OBJECTIVE: The authors’ goal was to examine interregional correlations of thalamocortical metabolic activity during a verbal learning task in schizophrenia. METHOD: They used [18F]fluorodeoxyglucose positron emission tomography in 41 unmedicated patients with schizophrenia and 59 normal comparison subjects. RESULTS: A metabolic disconnection was observed in patients with schizophrenia in the left hemisphere between the Mediodorsal Nucleus and widespread frontotemporal cortical regions, and stronger-than-normal intercorrelations were found between the pulvinar and superior temporal, selected parietal, posterior cingulate, and occipital areas. CONCLUSIONS: Deficits in the functional interrelationships between the left frontotemporal cortices and the left Mediodorsal Nucleus of the thalamus complement inferences from postmortem and magnetic resonance imaging volumetric studies identifying a thalamic diathesis in schizophrenia.
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Abnormal glucose metabolism in the Mediodorsal Nucleus of the thalamus in schizophrenia.
The American journal of psychiatry, 2004Co-Authors: Erin A. Hazlett, Cheuk Y Tang, Monte S. Buchsbaum, Eileen Kemether, Rachel Bloom, Jimcy Platholi, Adam M. Brickman, Lina Shihabuddin, William ByneAbstract:OBJECTIVE: Three thalamic nuclei—the Mediodorsal Nucleus, pulvinar, and centromedian Nucleus—each have unique reciprocal circuitry with cortical and subcortical areas known to be affected in schizophrenia. To determine if the disorder is also associated with dysfunction in the Mediodorsal Nucleus, pulvinar, and centromedian Nucleus, relative glucose metabolism in these regions was measured in a large group of unmedicated patients with schizophrenia. METHOD: [18F]-deoxyglucose positron emission tomography (PET) and matching T1-weighted magnetic resonance imaging (MRI) scans were obtained for 41 unmedicated patients with schizophrenia and 60 age- and sex-matched healthy subjects. The PET and MRI images for each subject were coregistered, and the whole thalamus, Mediodorsal Nucleus, pulvinar, and centromedian Nucleus were traced on the MRI image. Relative glucose metabolism in these regions was assessed. RESULTS: Patients with schizophrenia showed significantly lower relative glucose metabolism in the mediod...
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magnetic resonance imaging of the thalamic Mediodorsal Nucleus and pulvinar in schizophrenia and schizotypal personality disorder
Archives of General Psychiatry, 2001Co-Authors: William Byne, Monte S. Buchsbaum, Erin A. Hazlett, Eileen Kemether, Akbar Shinwari, Vivian Mitropoulou, Larry J SieverAbstract:Background: The importance of neuronal interactions in development, the cortical dependence of many thalamic nuclei, and the phenomenon of transsynaptic degeneration suggest possible abnormalities in thalamic nuclei with connections to other brain regions implicated in schizophrenia. Because frontal and temporal lobe volumes are diminished in schizophrenia, volume loss could characterize their primary thalamic relay nuclei (Mediodorsal Nucleus [MDN] and pulvinar). Methods: Tracers delineated the thalamus, MDN, and pulvinar on contiguous 1.2-mm magnetic resonance images in 12 schizophrenic patients, 12 with schizotypal personality disorder (SPD), and 12 normal control subjects. The MDN and pulvinar were rendered visible by means of a Sobel intensity-gradient filter. Results: Pixel overlap for delineation of all structures by independent tracers was at least 80%; intraclass correlations were r=0.78 for MDN and r=0.83 for pulvi
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three dimensional analysis with mri and pet of the size shape and function of the thalamus in the schizophrenia spectrum
American Journal of Psychiatry, 1999Co-Authors: Erin A. Hazlett, Monte S. Buchsbaum, William Byne, Lina Shihabuddin, Tsechung Wei, Jacqueline Spiegelcohen, Craig Geneve, Rayzel Kinderlehrer, Mehmet M Haznedar, Larry J SieverAbstract:OBJECTIVE: In an exploration of the schizophrenia spectrum, the authors compared thalamic size, shape, and metabolic activity in unmedicated patients with schizophrenia and schizotypal personality disorder to findings in age- and sex-matched healthy control subjects. METHOD: Coregistered magnetic resonance imaging (MRI) and positron emission tomography scans were obtained in 27 schizophrenic patients, 13 patients with schizotypal personality disorder, and 32 control subjects who performed a serial verbal learning test during tracer uptake. After thalamus edges were outlined on 1.2-mm MRI scans, a radial warping program yielded significance probability mapping in three dimensions. RESULTS: Significance probability mapping (with resampling) identified an area in the region of the Mediodorsal Nucleus bilaterally with significantly lower relative metabolism in the schizophrenia group than in either the control or schizotypal personality disorder groups, which did not differ from each other. The three groups d...
William Byne - One of the best experts on this subject based on the ideXlab platform.
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metabolic disconnection between the Mediodorsal Nucleus of the thalamus and cortical brodmann s areas of the left hemisphere in schizophrenia
American Journal of Psychiatry, 2005Co-Authors: Serge A Mitelman, Erin A. Hazlett, William Byne, Eileen Kemether, Monte S. BuchsbaumAbstract:OBJECTIVE: The authors’ goal was to examine interregional correlations of thalamocortical metabolic activity during a verbal learning task in schizophrenia. METHOD: They used [18F]fluorodeoxyglucose positron emission tomography in 41 unmedicated patients with schizophrenia and 59 normal comparison subjects. RESULTS: A metabolic disconnection was observed in patients with schizophrenia in the left hemisphere between the Mediodorsal Nucleus and widespread frontotemporal cortical regions, and stronger-than-normal intercorrelations were found between the pulvinar and superior temporal, selected parietal, posterior cingulate, and occipital areas. CONCLUSIONS: Deficits in the functional interrelationships between the left frontotemporal cortices and the left Mediodorsal Nucleus of the thalamus complement inferences from postmortem and magnetic resonance imaging volumetric studies identifying a thalamic diathesis in schizophrenia.
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Abnormal glucose metabolism in the Mediodorsal Nucleus of the thalamus in schizophrenia.
The American journal of psychiatry, 2004Co-Authors: Erin A. Hazlett, Cheuk Y Tang, Monte S. Buchsbaum, Eileen Kemether, Rachel Bloom, Jimcy Platholi, Adam M. Brickman, Lina Shihabuddin, William ByneAbstract:OBJECTIVE: Three thalamic nuclei—the Mediodorsal Nucleus, pulvinar, and centromedian Nucleus—each have unique reciprocal circuitry with cortical and subcortical areas known to be affected in schizophrenia. To determine if the disorder is also associated with dysfunction in the Mediodorsal Nucleus, pulvinar, and centromedian Nucleus, relative glucose metabolism in these regions was measured in a large group of unmedicated patients with schizophrenia. METHOD: [18F]-deoxyglucose positron emission tomography (PET) and matching T1-weighted magnetic resonance imaging (MRI) scans were obtained for 41 unmedicated patients with schizophrenia and 60 age- and sex-matched healthy subjects. The PET and MRI images for each subject were coregistered, and the whole thalamus, Mediodorsal Nucleus, pulvinar, and centromedian Nucleus were traced on the MRI image. Relative glucose metabolism in these regions was assessed. RESULTS: Patients with schizophrenia showed significantly lower relative glucose metabolism in the mediod...
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magnetic resonance imaging of the thalamic Mediodorsal Nucleus and pulvinar in schizophrenia and schizotypal personality disorder
Archives of General Psychiatry, 2001Co-Authors: William Byne, Monte S. Buchsbaum, Erin A. Hazlett, Eileen Kemether, Akbar Shinwari, Vivian Mitropoulou, Larry J SieverAbstract:Background: The importance of neuronal interactions in development, the cortical dependence of many thalamic nuclei, and the phenomenon of transsynaptic degeneration suggest possible abnormalities in thalamic nuclei with connections to other brain regions implicated in schizophrenia. Because frontal and temporal lobe volumes are diminished in schizophrenia, volume loss could characterize their primary thalamic relay nuclei (Mediodorsal Nucleus [MDN] and pulvinar). Methods: Tracers delineated the thalamus, MDN, and pulvinar on contiguous 1.2-mm magnetic resonance images in 12 schizophrenic patients, 12 with schizotypal personality disorder (SPD), and 12 normal control subjects. The MDN and pulvinar were rendered visible by means of a Sobel intensity-gradient filter. Results: Pixel overlap for delineation of all structures by independent tracers was at least 80%; intraclass correlations were r=0.78 for MDN and r=0.83 for pulvi
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three dimensional analysis with mri and pet of the size shape and function of the thalamus in the schizophrenia spectrum
American Journal of Psychiatry, 1999Co-Authors: Erin A. Hazlett, Monte S. Buchsbaum, William Byne, Lina Shihabuddin, Tsechung Wei, Jacqueline Spiegelcohen, Craig Geneve, Rayzel Kinderlehrer, Mehmet M Haznedar, Larry J SieverAbstract:OBJECTIVE: In an exploration of the schizophrenia spectrum, the authors compared thalamic size, shape, and metabolic activity in unmedicated patients with schizophrenia and schizotypal personality disorder to findings in age- and sex-matched healthy control subjects. METHOD: Coregistered magnetic resonance imaging (MRI) and positron emission tomography scans were obtained in 27 schizophrenic patients, 13 patients with schizotypal personality disorder, and 32 control subjects who performed a serial verbal learning test during tracer uptake. After thalamus edges were outlined on 1.2-mm MRI scans, a radial warping program yielded significance probability mapping in three dimensions. RESULTS: Significance probability mapping (with resampling) identified an area in the region of the Mediodorsal Nucleus bilaterally with significantly lower relative metabolism in the schizophrenia group than in either the control or schizotypal personality disorder groups, which did not differ from each other. The three groups d...
Shintaro Funahashi - One of the best experts on this subject based on the ideXlab platform.
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2016Co-Authors: Yumiko Funahashi, Shintaro Funahashi, Yumiko Watanabe, Thalamic Mediodorsal Nucleus, Working MemoryAbstract:Title Thalamic Mediodorsal Nucleus and working memory
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thalamic Mediodorsal Nucleus and its participation in spatial working memory processes comparison with the prefrontal cortex
Frontiers in Systems Neuroscience, 2013Co-Authors: Shintaro FunahashiAbstract:Working memory is a dynamic neural system that includes processes for temporarily maintaining and processing information. Working memory plays a significant role in a variety of cognitive functions, such as thinking, reasoning, decision-making, and language comprehension. Although the prefrontal cortex (PFC) is known to play an important role in working memory, several lines of evidence indicate that the thalamic Mediodorsal Nucleus (MD) also participates in this process. While monkeys perform spatial working memory tasks, MD neurons exhibit directionally selective delay-period activity, which is considered to be a neural correlate for the temporary maintenance of information in PFC neurons. Studies have also shown that, while most MD neurons maintain prospective motor information, some maintain retrospective sensory information. Thus, the MD plays a greater role in prospective motor aspects of working memory processes than the PFC, which participates more in retrospective aspects. For the performance of spatial working memory tasks, the information provided by a sensory cue needs to be transformed into motor information to give an appropriate response. A population vector analysis using neural activities revealed that, although the transformation of sensory-to-motor information occurred during the delay period in both the PFC and the MD, PFC activities maintained sensory information until the late phase of the delay period, while MD activities initially represented sensory information but then started to represent motor information in the earlier phase of the delay period. These results indicate that long-range neural interactions supported by reciprocal connections between the MD and the PFC could play an important role in the transformation of maintained information in working memory processes.
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thalamic Mediodorsal Nucleus and working memory
Neuroscience & Biobehavioral Reviews, 2012Co-Authors: Yumiko Watanabe, Shintaro FunahashiAbstract:Abstract Working memory is a dynamic neural system for temporarily maintaining and processing information. The prefrontal cortex (PFC) plays an important role in working memory. However, several evidences indicate that the thalamic Mediodorsal Nucleus (MD) also participates in working memory. Neurophysiological studies revealed that MD neurons exhibit sustained delay activity, which is considered to be a neural correlate of the temporary maintenance of information. Most MD neurons with delay activity represented information regarding motor responses, whereas some represented information regarding visual cues, suggesting that the MD participates more in prospective aspects of working memory, in contrast to the PFC, in which a minority participates in prospective aspects of working memory. A population vector analysis revealed that the transformation of sensory-to-motor information occurred during the earlier phase of the delay period in the MD compared with the PFC. These results indicate that reverberating neural circuits constructed by reciprocal connections between the MD and the PFC could be an important component for constructing prospective information in the PFC.
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neuronal activity throughout the primate Mediodorsal Nucleus of the thalamus during oculomotor delayed responses i cue delay and response period activity
Journal of Neurophysiology, 2004Co-Authors: Yumiko Watanabe, Shintaro FunahashiAbstract:The thalamic Mediodorsal Nucleus (MD) has strong reciprocal connections with the dorsolateral prefrontal cortex (DLPFC), suggesting that the MD, like the DLPFC, participates in higher cognitive fun...
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neuronal activity throughout the primate Mediodorsal Nucleus of the thalamus during oculomotor delayed responses ii activity encoding visual versus motor signal
Journal of Neurophysiology, 2004Co-Authors: Yumiko Watanabe, Shintaro FunahashiAbstract:We collected single-neuron activity from the Mediodorsal (MD) Nucleus of the thalamus, examined the information that was represented by task-related activity during performance of a spatial working...
Harry B M Uylings - One of the best experts on this subject based on the ideXlab platform.
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SPECIAL ISSUE CONTRIBUTIONS OF THALAMIC NUCLEI TO DECLARATIVE MEMORY FUNCTIONING
2015Co-Authors: D. Van, J Jolles, Menno P Witter, Der Werf, Harry B M UylingsAbstract:In spite of the acknowledged role that the thalamus plays in declarative memory, details about the precise memory processes it is involved in and which are the structures of the thalamus that contribute to these processes remain unknown. An overview is presented of human clinical and animal experimental findings showing the involvement of the thalamus, at the level of white matter tracts and separate nuclei, in aspects of memory functioning. The region in the thalamus that contributes to declarative memory is the anterior and medial division, containing the anterior nuclei, the medial dorsal Nucleus and the intralaminar and midline nuclei. A lesion to the anterior nuclei or their afferent white matter tract, the mammillothalamic tract, results in deficits of encoding of new stimuli. Lesions to the medial dorsal Nucleus affect executive processes pertaining to declarative memory, such as the use of memory strategies for retrieval; damage to the intralaminar and midline nuclei results in decreased arousal and thus affects the declarative memory process. Based on anatomical and functional data, a theory is proposed of how the thalamus might play a role at different levels of declarative memory functioning. Firstly, the anterior and Mediodorsal Nucleus ar
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contributions of thalamic nuclei to declarative memory functioning
Cortex, 2003Co-Authors: Ysbrand D Van Der Werf, J Jolles, Menno P Witter, Harry B M UylingsAbstract:In spite of the acknowledged role that the thalamus plays in declarative memory, details about the precise memory processes it is involved in and which are the structures of the thalamus that contribute to these processes remain unknown. An overview is presented of human clinical and animal experimental findings showing the involvement of the thalamus, at the level of white matter tracts and separate nuclei, in aspects of memory functioning. The region in the thalamus that contributes to declarative memory is the anterior and medial division, containing the anterior nuclei, the medial dorsal Nucleus and the intralaminar and midline nuclei. A lesion to the anterior nuclei or their afferent white matter tract, the mammillothalamic tract, results in deficits of encoding of new stimuli. Lesions to the medial dorsal Nucleus affect executive processes pertaining to declarative memory, such as the use of memory strategies for retrieval; damage to the intralaminar and midline nuclei results in decreased arousal and thus affects the declarative memory process. Based on anatomical and functional data, a theory is proposed of how the thalamus might play a role at different levels of declarative memory functioning. Firstly, the anterior and Mediodorsal Nucleus are involved in processing the contents of the stimuli for storage and recall. The anterior nuclei influence the selection of material to be stored and remembered, whereas the Mediodorsal Nucleus is involved in the coordination and selection of the strategies used to retrieve material. Secondly, the intralaminar and midline nuclei and specifically the lateral and ventral components, maintain a necessary state of the cortical regions involved in the ongoing memory processes. The two types of function subserved by these groups of thalamic nuclei, focussing on contents vs. state, need to work in parallel to mediate and allow memory functioning, respectively.
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neuropsychology of infarctions in the thalamus a review
Neuropsychologia, 2000Co-Authors: Ysbrand D Van Der Werf, Harry B M Uylings, Menno P Witte, J JollesAbstract:From a review of the literature on the consequences of thalamic infarctions, it may be concluded that memory problems taking the form of an amnesic syndrome are dependent upon the integrity of the mammillo-thalamic tract (MTT). Memory problems incompatible with an amnesic syndrome however, appear to result from thalamic infarctions involving other areas of the thalamus but which leave MTT intact. In contrast, executive dysfunctions could not be shown so readily to depend upon a single structure of the thalamus. The results indicate that damage to the Mediodorsal Nucleus of the thalamus, the midline nuclei or the intralaminar nuclei, or a combined lesion of these structures may be responsible for deficits of executive functioning. # 2000 Elsevier Science Ltd. All rights reserved.