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De Simone MS, Spalletta G, Vecchio D, Bassi A, Carlesimo GA, Piras F. The Role of the Anterior Thalamic Nuclei in the Genesis of Memory Disorders in Alzheimer's Disease: An Exploratory Study. J Alzheimers Dis 2024; 97:507-519. [PMID: 38189755 DOI: 10.3233/jad-230606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
BACKGROUND Increasing evidence is demonstrating that degeneration of specific thalamic nuclei, in addition to the hippocampus, may occur in Alzheimer's disease (AD) from the prodromal stage (mild cognitive impairment - MCI) and contribute to memory impairment. OBJECTIVE Here, we evaluated the presence of macro and micro structural alterations at the level of the anterior thalamic nuclei (ATN) and medio-dorsal thalamic nuclei (MDTN) in AD and amnestic MCI (aMCI) and the possible relationship between such changes and the severity of memory impairment. METHODS For this purpose, a sample of 50 patients with aMCI, 50 with AD, and 50 age- and education-matched healthy controls (HC) were submitted to a 3-T MRI protocol with whole-brain T1-weighted and diffusion tensor imaging and a comprehensive neuropsychological assessment. RESULTS At macro-structural level, both the ATN and MDTN were found significantly smaller in patients with aMCI and AD when compared to HC subjects. At micro-structural level, instead, diffusion alterations that significantly differentiated aMCI and AD patients from HC subjects were found only in the ATN, but not in the MDTN. Moreover, diffusion values of the ATN were significantly associated with poor episodic memory in the overall patients' group. CONCLUSIONS These findings represent the first in vivo evidence of a relevant involvement of ATN in the AD-related neurodegeneration and memory profile and strengthen the importance to look beyond the hippocampus when considering neurological conditions characterized by memory decline.
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Affiliation(s)
- Maria Stefania De Simone
- Department of Clinical Neuroscience and Neurorehabilitation, Laboratory of Neuropsychology of Memory, IRCCS Santa Lucia Foundation, Rome, Italy
- Niccolò Cusano University, Rome, Italy
| | - Gianfranco Spalletta
- Department of Clinical Neuroscience and Neurorehabilitation, Laboratory of Neuropsychiatry, IRCCS Santa Lucia Foundation, Rome, Italy
- Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, USA
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Daniela Vecchio
- Department of Clinical Neuroscience and Neurorehabilitation, Laboratory of Neuropsychiatry, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Andrea Bassi
- Department of Clinical Neuroscience and Neurorehabilitation, Laboratory of Neuropsychiatry, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Giovanni Augusto Carlesimo
- Department of Clinical Neuroscience and Neurorehabilitation, Laboratory of Neuropsychology of Memory, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
- Senior Authors
| | - Fabrizio Piras
- Department of Clinical Neuroscience and Neurorehabilitation, Laboratory of Neuropsychiatry, IRCCS Santa Lucia Foundation, Rome, Italy
- Senior Authors
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Aggleton JP, Vann SD, O'Mara SM. Converging diencephalic and hippocampal supports for episodic memory. Neuropsychologia 2023; 191:108728. [PMID: 37939875 DOI: 10.1016/j.neuropsychologia.2023.108728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/25/2023] [Accepted: 11/03/2023] [Indexed: 11/10/2023]
Abstract
To understand the neural basis of episodic memory it is necessary to appreciate the significance of the fornix. This pathway creates a direct link between those temporal lobe and medial diencephalic sites responsible for anterograde amnesia. A collaboration with Andrew Mayes made it possible to recruit and scan 38 patients with colloid cysts in the third ventricle, a condition associated with variable fornix damage. Complete fornix loss was seen in three patients, who suffered chronic long-term memory problems. Volumetric analyses involving all 38 patients then revealed a highly consistent relationship between mammillary body volume and the recall of episodic memory. That relationship was not seen for working memory or tests of recognition memory. Three different methods all supported a dissociation between recollective-based recognition (impaired) and familiarity-based recognition (spared). This dissociation helped to show how the mammillary body-anterior thalamic nuclei axis, as well as the hippocampus, is vital for episodic memory yet is not required for familiarity-based recognition. These findings set the scene for a reformulation of temporal lobe and diencephalic amnesia. In this revised model, these two regions converge on overlapping cortical areas, including retrosplenial cortex. The united actions of the hippocampal formation and the anterior thalamic nuclei on these cortical areas enable episodic memory encoding and consolidation, impacting on subsequent recall.
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Affiliation(s)
- John P Aggleton
- School of Psychology, Cardiff University, Cardiff, CF10 3AT, Wales, United Kingdom.
| | - Seralynne D Vann
- School of Psychology, Cardiff University, Cardiff, CF10 3AT, Wales, United Kingdom
| | - Shane M O'Mara
- School of Psychology and Trinity College Institute of Neuroscience, Trinity College, Dublin - the University of Dublin, Dublin, D02 PN40, Ireland.
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Venkatesh P, Wolfe C, Lega B. Neuromodulation of the anterior thalamus: Current approaches and opportunities for the future. CURRENT RESEARCH IN NEUROBIOLOGY 2023; 5:100109. [PMID: 38020810 PMCID: PMC10663132 DOI: 10.1016/j.crneur.2023.100109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 08/28/2023] [Accepted: 08/31/2023] [Indexed: 12/01/2023] Open
Abstract
The role of thalamocortical circuits in memory has driven a recent burst of scholarship, especially in animal models. Investigating this circuitry in humans is more challenging. And yet, the development of new recording and stimulation technologies deployed for clinical indications has created novel opportunities for data collection to elucidate the cognitive roles of thalamic structures. These technologies include stereoelectroencephalography (SEEG), deep brain stimulation (DBS), and responsive neurostimulation (RNS), all of which have been applied to memory-related thalamic regions, specifically for seizure localization and treatment. This review seeks to summarize the existing applications of neuromodulation of the anterior thalamic nuclei (ANT) and highlight several devices and their capabilities that can allow cognitive researchers to design experiments to assay its functionality. Our goal is to introduce to investigators, who may not be familiar with these clinical devices, the capabilities, and limitations of these tools for understanding the neurophysiology of the ANT as it pertains to memory and other behaviors. We also briefly cover the targeting of other thalamic regions including the centromedian (CM) nucleus, dorsomedial (DM) nucleus, and pulvinar, with associated potential avenues of experimentation.
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Affiliation(s)
- Pooja Venkatesh
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Cody Wolfe
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Bradley Lega
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
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Guo D, Chen H, Wang L, Yang J. Effects of prior knowledge on brain activation and functional connectivity during memory retrieval. Sci Rep 2023; 13:13650. [PMID: 37608065 PMCID: PMC10444832 DOI: 10.1038/s41598-023-40966-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 08/19/2023] [Indexed: 08/24/2023] Open
Abstract
Previous studies have shown that the ventral medial prefrontal cortex (vmPFC) plays an important role in schema-related memory. However, there is an intensive debate to what extent the activation of subregions of the hippocampus is involved in retrieving schema-related memory. In addition, it is unclear how the functional connectivity (FC) between the vmPFC and the hippocampus, as well as the connectivity of the vmPFC with other regions, are modulated by prior knowledge (PK) during memory retrieval over time. To address these issues, participants learned paragraphs that described features of each unfamiliar word from familiar and unfamiliar categories (i.e., high and low PK conditions) 20 min, 1 day, and 1 week before the test. They then performed a recognition task to judge whether the sentences were old in the scanner. The results showed that the activation of the anterior-medial hippocampus (amHPC) cluster was stronger when the old sentences with high (vs. low) PK were correctly retrieved. The activation of the posterior hippocampus (pHPC) cluster, as well as the vmPFC, was stronger when the new sentences with high (vs. low) PK were correctly rejected (i.e., CR trials), whereas the cluster of anterior-lateral hippocampus (alHPC) showed the opposite. The FC of the vmPFC with the amHPC and perirhinal cortex/inferior temporal gyrus was stronger in the high (vs. low) PK condition, whereas the FC of the vmPFC with the alHPC, thalamus and frontal regions showed the opposite for the CR trials. This study highlighted that different brain networks, which were associated with the vmPFC, subregions of the hippocampus and cognitive control regions, were responsible for retrieving the information with high and low PK.
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Affiliation(s)
- Dingrong Guo
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, 100871, China
| | - Haoyu Chen
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, 100871, China
| | - Lingwei Wang
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, 100871, China
| | - Jiongjiong Yang
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, 100871, China.
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Liyana Arachige M, Seneviratne U, John N, Ma H, Phan TG. Mapping topography and network of brain injury in patients with disorders of consciousness. Front Neurol 2023; 14:1027160. [PMID: 37064187 PMCID: PMC10090673 DOI: 10.3389/fneur.2023.1027160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 03/14/2023] [Indexed: 03/31/2023] Open
Abstract
BackgroundThere is a growing interest in the topography of brain regions associated with disorders of consciousness. This has caused increased research output, yielding many publications investigating the topic with varying methodologies. The objective of this study was to ascertain the topographical regions of the brain most frequently associated with disorders of consciousness.MethodsWe performed a cross-sectional text-mining analysis of disorders of consciousness studies. A text mining algorithm built in the Python programming language searched documents for anatomical brain terminology. We reviewed primary PubMed studies between January 1st 2000 to 8th February 2023 for the search query “Disorders of Consciousness.” The frequency of brain regions mentioned in these articles was recorded, ranked, then built into a graphical network. Subgroup analysis was performed by evaluating the impact on our results if analyses were based on abstracts, full-texts, or topic-modeled groups (non-negative matrix factorization was used to create subgroups of each collection based on their key topics). Brain terms were ranked by their frequency and concordance was measured between subgroups. Graphical analysis was performed to explore relationships between the anatomical regions mentioned. The PageRank algorithm (used by Google to list search results in order of relevance) was used to determine global importance of the regions.ResultsThe PubMed search yielded 24,944 abstracts and 3,780 full texts. The topic-modeled subgroups contained 2015 abstracts and 283 full texts. Text Mining across all document groups concordantly ranked the thalamus the highest (Savage score = 11.716), followed by the precuneus (Savage score = 4.983), hippocampus (Savage score = 4.483). Graphical analysis had 5 clusters with the thalamus once again having the highest PageRank score (PageRank = 0.0344).ConclusionThe thalamus, precuneus and cingulate cortex are strongly associated with disorders of consciousness, likely due to the roles they play in maintaining awareness and involvement in the default mode network, respectively. The findings also suggest that other areas of the brain like the cerebellum, cuneus, amygdala and hippocampus also share connections to consciousness should be further investigated.
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Affiliation(s)
- Manoj Liyana Arachige
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia
- Department of Neurology, Monash Health, Clayton, VIC, Australia
| | - Udaya Seneviratne
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia
- Department of Neurology, Monash Health, Clayton, VIC, Australia
| | - Nevin John
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia
- Department of Neurology, Monash Health, Clayton, VIC, Australia
| | - Henry Ma
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia
- Department of Neurology, Monash Health, Clayton, VIC, Australia
| | - Thanh G. Phan
- Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia
- Department of Neurology, Monash Health, Clayton, VIC, Australia
- *Correspondence: Thanh G. Phan,
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Hamilton JJ, Dalrymple‐Alford JC. Anterior thalamic nuclei: A critical substrate for non-spatial paired-associate memory in rats. Eur J Neurosci 2022; 56:5014-5032. [PMID: 35985792 PMCID: PMC9804733 DOI: 10.1111/ejn.15802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 06/30/2022] [Accepted: 08/15/2022] [Indexed: 01/09/2023]
Abstract
Injury or dysfunction in the anterior thalamic nuclei (ATN) may be the key contributory factor in many instances of diencephalic amnesia. Experimental ATN lesions impair spatial memory and temporal discriminations, but there is only limited support for a more general role in non-spatial memory. To extend evidence on the effects of ATN lesions, we examined the acquisition of biconditional associations between odour and object pairings presented in a runway, either with or without a temporal gap between these items. Intact adult male rats acquired both the no-trace and 10-s trace versions of this non-spatial task. Intact rats trained in the trace version showed elevated Zif268 activation in the dorsal CA1 of the hippocampus, suggesting that the temporal component recruited additional neural processing. ATN lesions completely blocked acquisition on both versions of this association-memory task. This deficit was not due to poor inhibition to non-rewarded cues or impaired sensory processing, because rats with ATN lesions were unimpaired in the acquisition of simple odour discriminations and simple object discriminations using similar task demands in the same apparatus. This evidence challenges the view that impairments in arbitrary paired-associate learning after ATN lesions require the use of multimodal spatial stimuli. It suggests that diencephalic amnesia associated with the ATN stems from degraded attention to stimulus-stimulus associations and their representation across a distributed memory system.
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Affiliation(s)
- Jennifer J. Hamilton
- School of Psychology, Speech and HearingUniversity of CanterburyChristchurchNew Zealand,New Zealand Brain Research InstituteChristchurchNew Zealand,Brain Research New Zealand – Rangahau Roro AotearoaAucklandNew Zealand
| | - John C. Dalrymple‐Alford
- School of Psychology, Speech and HearingUniversity of CanterburyChristchurchNew Zealand,New Zealand Brain Research InstituteChristchurchNew Zealand,Brain Research New Zealand – Rangahau Roro AotearoaAucklandNew Zealand
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Szabó JP, Fabó D, Pető N, Sákovics A, Bódizs R. Role of anterior thalamic circuitry during sleep. Epilepsy Res 2022; 186:106999. [DOI: 10.1016/j.eplepsyres.2022.106999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/22/2022] [Accepted: 08/10/2022] [Indexed: 12/01/2022]
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Zhang Q, Wu J, Pei C, Ma M, Dong Y, Gao M, Zhang H. Altered functional connectivity in emotional subregions of the anterior cingulate cortex in young and middle-aged patients with major depressive disorder: A resting-state fMRI study. Biol Psychol 2022; 175:108426. [PMID: 36152733 DOI: 10.1016/j.biopsycho.2022.108426] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 09/08/2022] [Accepted: 09/19/2022] [Indexed: 11/02/2022]
Abstract
BACKGROUND It has been demonstrated that the anterior cingulate cortex (ACC) has three subregions, involved in behavior, cognition, and emotion. However, the intrinsic connectivity of the ACC subregions in patients with major depressive disorder (MDD) is still unclear. In this study, functional magnetic resonance imaging (fMRI) data was used to detect the functional connectivity (FC) of ACC subregions and the correlation with the disease severity in young and middle-aged patients with MDD. METHODS A total of 36 young and middle-aged patients with first-episode MDD and 36 healthy controls (HCs) were enrolled in this study. FC was applied to investigate altered connectivity of the ACC subregion in MDD patients compared to HCs. Correlation analysis was then used to assess possible relationship between the neuroimaging findings and clinical symptoms in the patient group. RESULTS Compared to HCs, young and middle-aged patients had significantly decreased FC between the emotional subregion of the ACC and the hippocampus, thalamus, insula, angular gyrus, and posterior cingulate cortex. The FC between the ACC emotional subregion and the insula, the AG, the RPHG was negatively correlated with depression index. The FC between the ACC emotional subregion and the putamen was positively correlated with depression index. CONCLUSION The present findings indicate that abnormal ACC subregions-seeded FC may be implicated in the MDD-related abnormalities of emotion regulation and information processing. And there is a correlation between the above FC changes and the clinical symptoms of young and middle-aged MDD patients. This study may provide preliminary evidence for the ACC-related neural mechanism in young and middle-aged MDD patients and enhance the understanding of the pathophysiology of MDD.
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Affiliation(s)
- Qiaoying Zhang
- Department of Radiology, the Affiliated Xi'an Central Hospital of Xi'an Jiaotong University Health Science Center, Xi'an 710003, China
| | - Jiayu Wu
- Department of Radiology, the Affiliated Xi'an Central Hospital of Xi'an Jiaotong University Health Science Center, Xi'an 710003, China
| | - Caixia Pei
- Department of Radiology, the Affiliated Xi'an Central Hospital of Xi'an Jiaotong University Health Science Center, Xi'an 710003, China
| | - Mingyue Ma
- Department of Radiology, the Affiliated Xi'an Central Hospital of Xi'an Jiaotong University Health Science Center, Xi'an 710003, China
| | - Yan Dong
- Department of Radiology, the Affiliated Xi'an Central Hospital of Xi'an Jiaotong University Health Science Center, Xi'an 710003, China
| | - Ming Gao
- Department of Radiology, the Affiliated Xi'an Central Hospital of Xi'an Jiaotong University Health Science Center, Xi'an 710003, China
| | - Hong Zhang
- Department of Radiology, the Affiliated Xi'an Central Hospital of Xi'an Jiaotong University Health Science Center, Xi'an 710003, China.
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Aggleton JP, Nelson AJD, O'Mara SM. Time to retire the serial Papez circuit: Implications for space, memory, and attention. Neurosci Biobehav Rev 2022; 140:104813. [PMID: 35940310 PMCID: PMC10804970 DOI: 10.1016/j.neubiorev.2022.104813] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/20/2022] [Accepted: 08/01/2022] [Indexed: 11/26/2022]
Abstract
After more than 80 years, Papez serial circuit remains a hugely influential concept, initially for emotion, but in more recent decades, for memory. Here, we show how this circuit is anatomically and mechanistically naïve as well as outdated. We argue that a new conceptualisation is necessitated by recent anatomical and functional findings that emphasize the more equal, working partnerships between the anterior thalamic nuclei and the hippocampal formation, along with their neocortical interactions in supporting, episodic memory. Furthermore, despite the importance of the anterior thalamic for mnemonic processing, there is growing evidence that these nuclei support multiple aspects of cognition, only some of which are directly associated with hippocampal function. By viewing the anterior thalamic nuclei as a multifunctional hub, a clearer picture emerges of extra-hippocampal regions supporting memory. The reformulation presented here underlines the need to retire Papez serially processing circuit.
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Affiliation(s)
- John P Aggleton
- School of Psychology, Cardiff University, 70 Park Place, Cardiff CF10 3AT, Wales, UK.
| | - Andrew J D Nelson
- School of Psychology, Cardiff University, 70 Park Place, Cardiff CF10 3AT, Wales, UK
| | - Shane M O'Mara
- School of Psychology and Trinity College Institute of Neuroscience, Trinity College Dublin, The University of Dublin, Dublin D02 PN40, Ireland
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Forgetting the Unforgettable: Transient Global Amnesia Part II: A Clinical Road Map. J Clin Med 2022; 11:jcm11143940. [PMID: 35887703 PMCID: PMC9319625 DOI: 10.3390/jcm11143940] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 07/03/2022] [Accepted: 07/05/2022] [Indexed: 12/14/2022] Open
Abstract
Transient global amnesia (TGA) is a clinical syndrome characterized by the sudden onset of a temporary memory disorder with profound anterograde amnesia and a variable impairment of the past memory. Usually, the attacks are preceded by a precipitating event, last up to 24 h and are not associated with other neurological deficits. Diagnosis can be challenging because the identification of TGA requires the exclusion of some acute amnestic syndromes that occur in emergency situations and share structural or functional alterations of memory circuits. Magnetic Resonance Imaging (MRI) studies performed 24–96 h after symptom onset can help to confirm the diagnosis by identifying lesions in the CA1 field of the hippocampal cornu ammonis, but their practical utility in changing the management of patients is a matter of discussion. In this review, we aim to provide a practical approach to early recognition of this condition in daily practice, highlighting both the lights and the shadows of the diagnostic criteria. For this purpose, we summarize current knowledge about the clinical presentation, diagnostic pathways, differential diagnosis, and the expected long-term outcome of TGA.
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Rowland C, Harland B, Smith JH, Moslehi S, Dalrymple-Alford J, Taylor RP. Investigating Fractal Analysis as a Diagnostic Tool That Probes the Connectivity of Hippocampal Neurons. Front Physiol 2022; 13:932598. [PMID: 35812343 PMCID: PMC9260144 DOI: 10.3389/fphys.2022.932598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 05/31/2022] [Indexed: 11/30/2022] Open
Abstract
Many of nature’s fractal objects benefit from the favorable functionality that results from their pattern repetition at multiple scales. Our recent research focused on the importance of fractal scaling in establishing connectivity between neurons. Fractal dimension DA of the neuron arbors was shown to relate to the optimization of competing functional constraints—the ability of dendrites to connect to other neurons versus the costs associated with building the dendrites. Here, we consider whether pathological states of neurons might affect this fractal optimization and if changes in DA might therefore be used as a diagnostic tool in parallel with traditional measures like Sholl analyses. We use confocal microscopy to obtain images of CA1 pyramidal neurons in the coronal plane of the dorsal rat hippocampus and construct 3-dimensional models of the dendritic arbors using Neurolucida software. We examine six rodent groups which vary in brain condition (whether they had lesions in the anterior thalamic nuclei, ATN) and experience (their housing environment and experience in a spatial task). Previously, we showed ATN lesions reduced spine density in hippocampal CA1 neurons, whereas enriched housing increased spine density in both ATN lesion and sham rats. Here, we investigate whether ATN lesions and experience also effect the complexity and connectivity of CA1 dendritic arbors. We show that sham rats exposed to enriched housing and spatial memory training exhibited higher complexity (as measured by DA) and connectivity compared to other groups. When we categorize the rodent groups into those with or without lesions, we find that both categories achieve an optimal balance of connectivity with respect to material cost. However, the DA value used to achieve this optimization does not change between these two categories, suggesting any morphological differences induced by the lesions are too small to influence the optimization process. Accordingly, we highlight considerations associated with applying our technique to publicly accessible repositories of neuron images with a broader range of pathological conditions.
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Affiliation(s)
- Conor Rowland
- Physics Department, University of Oregon, Eugene, OR, United States
| | - Bruce Harland
- School of Pharmacy, University of Auckland, Auckland, New Zealand
| | - Julian H. Smith
- Physics Department, University of Oregon, Eugene, OR, United States
| | - Saba Moslehi
- Physics Department, University of Oregon, Eugene, OR, United States
| | - John Dalrymple-Alford
- School of Psychology, Speech and Hearing, University of Canterbury, Christchurch, New Zealand
- New Zealand Brain Research Institute, Christchurch, New Zealand
| | - Richard P. Taylor
- Physics Department, University of Oregon, Eugene, OR, United States
- *Correspondence: Richard P. Taylor,
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12
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The anterior thalamic nuclei: core components of a tripartite episodic memory system. Nat Rev Neurosci 2022; 23:505-516. [PMID: 35478245 DOI: 10.1038/s41583-022-00591-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2022] [Indexed: 12/13/2022]
Abstract
Standard models of episodic memory focus on hippocampal-parahippocampal interactions, with the neocortex supplying sensory information and providing a final repository of mnemonic representations. However, recent advances have shown that other regions make distinct and equally critical contributions to memory. In particular, there is growing evidence that the anterior thalamic nuclei have a number of key cognitive functions that support episodic memory. In this article, we describe these findings and argue for a core, tripartite memory system, comprising a 'temporal lobe' stream (centred on the hippocampus) and a 'medial diencephalic' stream (centred on the anterior thalamic nuclei) that together act on shared cortical areas. We demonstrate how these distributed brain regions form complementary and necessary partnerships in episodic memory formation.
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13
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Scharf AC, Gronewold J, Todica O, Moenninghoff C, Doeppner TR, de Haan B, Bassetti CLA, Hermann DM. Evolution of Neuropsychological Deficits in First-Ever Isolated Ischemic Thalamic Stroke and Their Association With Stroke Topography: A Case-Control Study. Stroke 2022; 53:1904-1914. [PMID: 35259928 PMCID: PMC9126267 DOI: 10.1161/strokeaha.121.037750] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The thalamus plays an essential role in cognition. Cognitive deficits have to date mostly been studied retrospectively in chronic thalamic stroke in small cohorts. Studies prospectively evaluating the evolution of cognitive deficits and their association with thalamic stroke topography are lacking. This knowledge is relevant for targeted patient diagnostics and rehabilitation.
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Affiliation(s)
- Anne-Carina Scharf
- Department of Neurology, University Hospital Essen, University of Duisburg-Essen, Germany. (A.-C.S., J.G., O.T., D.M.H.)
| | - Janine Gronewold
- Department of Neurology, University Hospital Essen, University of Duisburg-Essen, Germany. (A.-C.S., J.G., O.T., D.M.H.)
| | - Olga Todica
- Department of Neurology, University Hospital Essen, University of Duisburg-Essen, Germany. (A.-C.S., J.G., O.T., D.M.H.)
| | - Christoph Moenninghoff
- Institute of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, University of Duisburg-Essen, Germany. (C.M.)
| | - Thorsten R Doeppner
- Department of Neurology, University Medical Center Goettingen, Germany (T.R.D.)
| | - Bianca de Haan
- Division of Psychology, Department of Life Sciences, Centre for Cognitive Neuroscience, College of Health, Medicine and Life Sciences, Brunel University London, United Kingdom (B.d.H.)
| | | | - Dirk M Hermann
- Department of Neurology, University Hospital Essen, University of Duisburg-Essen, Germany. (A.-C.S., J.G., O.T., D.M.H.)
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Abstract
Since the first description of the case of H.M. in the mid-1950s, the debate over the contribution of the mesial temporal lobe (MTL) to human memory functioning has not ceased to stimulate new experimental work and the development of new theoretical models. The early demonstration that despite their devastating memory loss patients with hippocampal damage are still able to learn a number of visuo-motor and visuo-perceptual skills at a normal rate and to be normally primed by verbal and visual material suggested that the term "memory" is actually an umbrella concept that includes very different brain plasticity phenomena and that MTL damage actually impairs only one of these. Subsequent research, which capitalized on a detailed anatomical description of MTL structures and on the close analysis of memory-related phenomena, tried to define the unique role of the MTL structures in brain plasticity and in the government of human behavior. A first hypothesis identified this role in the conscious forms of memory as opposed to implicit ones. In the last two decades, the emphasis has moved to the relational role of the hippocampus in binding together different pieces of unimodal information to provide unitary, multimodal representations of personal experiences.
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Affiliation(s)
- Giovanni A Carlesimo
- Department of Systems Medicine, Tor Vergata University, Rome, Italy; Clinical and Behavioral Neurology Laboratory, I.R.C.C.S. Santa Lucia Foundation, Rome, Italy.
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15
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The Fornix May Play a Key Role in Korsakoff's Amnesia Secondary to Subcallosal Artery Infarction. Brain Sci 2021; 12:brainsci12010021. [PMID: 35053765 PMCID: PMC8773842 DOI: 10.3390/brainsci12010021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/22/2021] [Accepted: 12/22/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Subcallosal artery infarction injures the fornix and anterior corpus callosum and sometimes causes Korsakoff's amnesia. We hypothesized that Korsakoff's amnesia might be caused by fornix dysfunction rather than anterior corpus callosum dysfunction in subcallosal artery infarction. METHODS A systematic review approach was applied to search PubMed and Google Scholar for articles to compare patients who had both bilateral fornix and corpus callosum infarction due to subcallosal artery territory ischemia (vascular event group; V group) with patients who had undergone anterior corpus callosotomy (callosotomy group; C group). RESULTS The V group comprised 10 patients (mean age, 63 years; median, 69 years; standard deviation (SD), 14.5 years; 5 males, 5 females). The C group comprised 6 patients (mean age, 23.7 years; median, 20 years; SD, 7.3 years; 3 males, 3 females). Six of 10 patients (60%) with subcallosal artery infarction exhibited Korsakoff's amnesia. One patient showed neither confabulation nor amnesia. Conversely, no amnesia episodes were seen in any patients from the C group (p = 0.034). CONCLUSION Fornix injury, rather than anterior corpus callosum injury, might be the major cause of Korsakoff's amnesia in patients with subcallosal artery infarction.
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16
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Forno G, Lladó A, Hornberger M. Going round in circles-The Papez circuit in Alzheimer's disease. Eur J Neurosci 2021; 54:7668-7687. [PMID: 34656073 DOI: 10.1111/ejn.15494] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 10/01/2021] [Accepted: 10/12/2021] [Indexed: 11/29/2022]
Abstract
The hippocampus is regarded as the pivotal structure for episodic memory symptoms associated with Alzheimer's disease (AD) pathophysiology. However, what is often overlooked is that the hippocampus is 'only' one part of a network of memory critical regions, the Papez circuit. Other Papez circuit regions are often regarded as less relevant for AD as they are thought to sit 'downstream' of the hippocampus. However, this notion is oversimplistic, and increasing evidence suggests that other Papez regions might be affected before or concurrently with the hippocampus. In addition, AD research has mostly focused on episodic memory deficits, whereas spatial navigation processes are also subserved by the Papez circuit with increasing evidence supporting its valuable potential as a diagnostic measure of incipient AD pathophysiology. In the current review, we take a step forward analysing recent evidence on the structural and functional integrity of the Papez circuit across AD disease stages. Specifically, we will review the integrity of specific Papez regions from at-genetic-risk (APOE4 carriers), to mild cognitive impairment (MCI), to dementia stage of sporadic AD and autosomal dominant AD (ADAD). We related those changes to episodic memory and spatial navigation/orientation deficits in AD. Finally, we provide an overview of how the Papez circuit is affected in AD diseases and their specific symptomology contributions. This overview strengthened the need for moving away from a hippocampal-centric view to a network approach on how the whole Papez circuit is affected in AD and contributes to its symptomology, informing future research and clinical approaches.
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Affiliation(s)
- Gonzalo Forno
- Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain.,School of Psychology, Universidad de los Andes, Santiago, Chile.,Neuropsychology and Clinical Neuroscience Laboratory (LANNEC), Physiopathology Department, ICBM, Neurosciences Department, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Albert Lladó
- Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clínic of Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, CIBERNED, Madrid, Spain
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17
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The specificity of thalamic alterations in Korsakoff's syndrome: Implications for the study of amnesia. Neurosci Biobehav Rev 2021; 130:292-300. [PMID: 34454914 DOI: 10.1016/j.neubiorev.2021.07.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 04/01/2021] [Accepted: 07/15/2021] [Indexed: 02/07/2023]
Abstract
The pathophysiological mechanisms behind amnesia are still unknown. Recent literature, through the study of patients with Alcohol Use Disorder with and without Korsakoff's syndrome, increasingly shows that physiological alterations to the thalamus have an important role in the development of amnesia. This review gives an overview of neuropsychological, neuropathological and neuroimaging contributions to the understanding of Korsakoff's syndrome, highlighting the central role of the thalamus in this amnesia. The thalamus being a multi-nucleus structure, the limitations regarding the loci, nature and alterations to specific nuclei are discussed, along with potential solutions. Finally, future directions for clinical research are laid out to unravel the intricacies inherent to amnesia. They consider the need to evaluate the physiological role of the thalamus, not only as an entity but also as part of a brain circuit through a more integrative approach.
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18
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Frost BE, Martin SK, Cafalchio M, Islam MN, Aggleton JP, O'Mara SM. Anterior Thalamic Inputs Are Required for Subiculum Spatial Coding, with Associated Consequences for Hippocampal Spatial Memory. J Neurosci 2021; 41:6511-6525. [PMID: 34131030 PMCID: PMC8318085 DOI: 10.1523/jneurosci.2868-20.2021] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/24/2021] [Accepted: 03/28/2021] [Indexed: 11/21/2022] Open
Abstract
Just as hippocampal lesions are principally responsible for "temporal lobe" amnesia, lesions affecting the anterior thalamic nuclei seem principally responsible for a similar loss of memory, "diencephalic" amnesia. Compared with the former, the causes of diencephalic amnesia have remained elusive. A potential clue comes from how the two sites are interconnected, as within the hippocampal formation, only the subiculum has direct, reciprocal connections with the anterior thalamic nuclei. We found that both permanent and reversible anterior thalamic nuclei lesions in male rats cause a cessation of subicular spatial signaling, reduce spatial memory performance to chance, but leave hippocampal CA1 place cells largely unaffected. We suggest that a core element of diencephalic amnesia stems from the information loss in hippocampal output regions following anterior thalamic pathology.SIGNIFICANCE STATEMENT At present, we know little about interactions between temporal lobe and diencephalic memory systems. Here, we focused on the subiculum, as the sole hippocampal formation region directly interconnected with the anterior thalamic nuclei. We combined reversible and permanent lesions of the anterior thalamic nuclei, electrophysiological recordings of the subiculum, and behavioral analyses. Our results were striking and clear: following permanent thalamic lesions, the diverse spatial signals normally found in the subiculum (including place cells, grid cells, and head-direction cells) all disappeared. Anterior thalamic lesions had no discernible impact on hippocampal CA1 place fields. Thus, spatial firing activity within the subiculum requires anterior thalamic function, as does successful spatial memory performance. Our findings provide a key missing part of the much bigger puzzle concerning why anterior thalamic damage is so catastrophic for spatial memory in rodents and episodic memory in humans.
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Affiliation(s)
- Bethany E Frost
- School of Psychology and Institute of Neuroscience, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Sean K Martin
- School of Psychology and Institute of Neuroscience, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Matheus Cafalchio
- School of Psychology and Institute of Neuroscience, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - Md Nurul Islam
- School of Psychology and Institute of Neuroscience, Trinity College Dublin, Dublin, D02 PN40, Ireland
| | - John P Aggleton
- School of Psychology, Cardiff University, Cardiff, CF10 3AS, United Kingdom
| | - Shane M O'Mara
- School of Psychology and Institute of Neuroscience, Trinity College Dublin, Dublin, D02 PN40, Ireland
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19
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Mair RG, Francoeur MJ, Gibson BM. Central Thalamic-Medial Prefrontal Control of Adaptive Responding in the Rat: Many Players in the Chamber. Front Behav Neurosci 2021; 15:642204. [PMID: 33897387 PMCID: PMC8060444 DOI: 10.3389/fnbeh.2021.642204] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/08/2021] [Indexed: 11/13/2022] Open
Abstract
The medial prefrontal cortex (mPFC) has robust afferent and efferent connections with multiple nuclei clustered in the central thalamus. These nuclei are elements in large-scale networks linking mPFC with the hippocampus, basal ganglia, amygdala, other cortical areas, and visceral and arousal systems in the brainstem that give rise to adaptive goal-directed behavior. Lesions of the mediodorsal nucleus (MD), the main source of thalamic input to middle layers of PFC, have limited effects on delayed conditional discriminations, like DMTP and DNMTP, that depend on mPFC. Recent evidence suggests that MD sustains and amplifies neuronal responses in mPFC that represent salient task-related information and is important for detecting and encoding contingencies between actions and their consequences. Lesions of rostral intralaminar (rIL) and ventromedial (VM) nuclei produce delay-independent impairments of egocentric DMTP and DNMTP that resemble effects of mPFC lesions on response speed and accuracy: results consistent with projections of rIL to striatum and VM to motor cortices. The ventral midline and anterior thalamic nuclei affect allocentric spatial cognition and memory consistent with their connections to mPFC and hippocampus. The dorsal midline nuclei spare DMTP and DNMTP. They have been implicated in behavioral-state control and response to salient stimuli in associative learning. mPFC functions are served during DNMTP by discrete populations of neurons with responses related to motor preparation, movements, lever press responses, reinforcement anticipation, reinforcement delivery, and memory delay. Population analyses show that different responses are timed so that they effectively tile the temporal interval from when DNMTP trials are initiated until the end. Event-related responses of MD neurons during DNMTP are predominantly related to movement and reinforcement, information important for DNMTP choice. These responses closely mirror the activity of mPFC neurons with similar responses. Pharmacological inactivation of MD and adjacent rIL affects the expression of diverse action- and outcome-related responses of mPFC neurons. Lesions of MD before training are associated with a shift away from movement-related responses in mPFC important for DNMTP choice. These results suggest that MD has short-term effects on the expression of event-related activity in mPFC and long-term effects that tune mPFC neurons to respond to task-specific information.
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Affiliation(s)
- Robert G Mair
- Department of Psychology, University of New Hampshire, Durham, NH, United States
| | - Miranda J Francoeur
- Department of Psychology, University of New Hampshire, Durham, NH, United States.,Neural Engineering and Translation Lab, University of California, San Diego, San Diego, CA, United States
| | - Brett M Gibson
- Department of Psychology, University of New Hampshire, Durham, NH, United States
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20
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Sierk A, Manthey A, Brakemeier EL, Walter H, Daniels JK. The dissociative subtype of posttraumatic stress disorder is associated with subcortical white matter network alterations. Brain Imaging Behav 2021; 15:643-655. [PMID: 32342260 PMCID: PMC8032639 DOI: 10.1007/s11682-020-00274-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Posttraumatic stress disorder (PTSD) is characterized by intrusions, avoidance, and hyperarousal while patients of the dissociative subtype (PTSD-D) experience additional dissociative symptoms. A neurobiological model proposes hyper-inhibition of limbic structures mediated by prefrontal cortices to underlie dissociation in PTSD. Here, we tested whether functional alterations in fronto-limbic circuits are underpinned by white matter network abnormalities on a network level. 23 women with PTSD-D and 19 women with classic PTSD participated. We employed deterministic diffusion tractography and graph theoretical analyses. Mean fractional anisotropy (FA) was chosen as a network weight and group differences assessed using network-based statistics. No significant white matter network alterations comprising both frontal and limbic structures in PTSD-D relative to classic PTSD were found. A subsequent whole brain exploratory analysis revealed relative FA alterations in PTSD-D in two subcortical networks, comprising connections between the left amygdala, hippocampus, and thalamus as well as links between the left ventral diencephalon, putamen, and pallidum, respectively. Dissociative symptom severity in the PTSD-D group correlated with FA values within both networks. Our findings suggest fronto-limbic inhibition in PTSD-D may present a dynamic neural process, which is not hard-wired via white matter tracts. Our exploratory results point towards altered fiber tract communication in a limbic-thalamic circuit, which may underlie (a) an initial strong emotional reaction to trauma reminders before conscious regulatory processes are enabled and (b) deficits in early sensory processing. In addition, aberrant structural connectivity in low-level motor regions may present neural correlates for dissociation as a passive threat-response.
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Affiliation(s)
- Anika Sierk
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany, Berlin, Germany
- Institute of Cognitive Neuroscience, University College London, London, UK
| | - Antje Manthey
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany, Berlin, Germany
| | - Eva-Lotta Brakemeier
- Department of Psychology & Marburg Center for Mind, Brain and Behavior (MCMBB), Philipps-Universität Marburg, Marburg, Germany
- Department of Clinical Psychology, University of Groningen, Groningen, Netherlands
| | - Henrik Walter
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany, Berlin, Germany
| | - Judith K Daniels
- Department of Clinical Psychology, University of Groningen, Groningen, Netherlands.
- Psychologische Hochschule Berlin, Berlin, Germany.
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21
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Nelson AJD. The anterior thalamic nuclei and cognition: A role beyond space? Neurosci Biobehav Rev 2021; 126:1-11. [PMID: 33737105 PMCID: PMC8363507 DOI: 10.1016/j.neubiorev.2021.02.047] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 12/25/2022]
Abstract
Anterior thalamic nuclei important for specific classes of temporal discriminations. Anterior thalamic nuclei required for hippocampal-dependent contextual processes. Critical role for anterior thalamic nuclei in selective attention. Significance of anterior thalamic – anterior cingulate interactions.
The anterior thalamic nuclei are a vital node within hippocampal-diencephalic-cingulate circuits that support spatial learning and memory. Reflecting this interconnectivity, the overwhelming focus of research into the cognitive functions of the anterior thalamic nuclei has been spatial processing. However, there is increasing evidence that the functions of the anterior thalamic nuclei extend beyond the spatial realm. This work has highlighted how these nuclei are required for certain classes of temporal discrimination as well as their importance for processing other contextual information; revealing parallels with the non-spatial functions of the hippocampal formation. Yet further work has shown how the anterior thalamic nuclei may be important for other forms of non-spatial learning, including a critical role for these nuclei in attentional mechanisms. This evidence signals the need to reconsider the functions of the anterior thalamic within the framework of their wider connections with sites including the anterior cingulate cortex that subserve non-spatial functions.
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Affiliation(s)
- Andrew J D Nelson
- School of Psychology, Cardiff University, 70 Park Place, Cardiff, CF10 3AT, Wales, UK.
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22
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Marin-Marin L, Palomar-García MÁ, Miró-Padilla A, Adrián-Ventura J, Aguirre N, Villar-Rodríguez E, Costumero V. Bilingualism's Effects on Resting-State Functional Connectivity in Mild Cognitive Impairment. Brain Connect 2021; 11:30-37. [PMID: 33307994 DOI: 10.1089/brain.2020.0877] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background: Bilingualism is considered a cognitive reserve (CR) factor, due to the delay in the onset of dementia in bilinguals compared with monolinguals. Two neural mechanisms have been suggested to underlie CR: neural reserve and neural compensation. However, it is still unclear how bilingualism contributes to these mechanisms. Methods: In this study, we used cognitive tests, functional connectivity (FC), regional homogeneity, and fractional amplitude of low-frequency fluctuations (fALFF) measures to study resting-state brain patterns in a sample of bilingual and monolingual subjects with mild cognitive impairment. Results: We found no significant differences between the groups in age, sex, education, or cognitive level, but bilinguals showed higher FC than monolinguals between the posterior part of the superior temporal gyrus and the precuneus, positively correlated with Mini-Mental State Examination scores, and higher fALFF in the thalamus bilaterally. Conclusions: Our results suggest that bilingualism may act as a CR factor that protects against dementia through neural compensation.
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Affiliation(s)
- Lidón Marin-Marin
- Neuropsychology and Functional Neuroimaging Group, Department of Basic Psychology, Clinical Psychology and Psychobiology, University Jaume I, Castelló, Spain
| | - María-Ángeles Palomar-García
- Neuropsychology and Functional Neuroimaging Group, Department of Basic Psychology, Clinical Psychology and Psychobiology, University Jaume I, Castelló, Spain
| | - Anna Miró-Padilla
- Neuropsychology and Functional Neuroimaging Group, Department of Basic Psychology, Clinical Psychology and Psychobiology, University Jaume I, Castelló, Spain
| | - Jesús Adrián-Ventura
- Neuropsychology and Functional Neuroimaging Group, Department of Basic Psychology, Clinical Psychology and Psychobiology, University Jaume I, Castelló, Spain
| | - Naiara Aguirre
- Neuropsychology and Functional Neuroimaging Group, Department of Basic Psychology, Clinical Psychology and Psychobiology, University Jaume I, Castelló, Spain
| | - Esteban Villar-Rodríguez
- Neuropsychology and Functional Neuroimaging Group, Department of Basic Psychology, Clinical Psychology and Psychobiology, University Jaume I, Castelló, Spain
| | - Victor Costumero
- Neuropsychology and Functional Neuroimaging Group, Department of Basic Psychology, Clinical Psychology and Psychobiology, University Jaume I, Castelló, Spain.,Center for Brain and Cognition, University Pompeu Fabra, Barcelona, Spain
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23
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Barnett S, Parr-Brownlie L, Perry B, Young C, Wicky H, Hughes S, McNaughton N, Dalrymple-Alford J. Anterior thalamic nuclei neurons sustain memory. CURRENT RESEARCH IN NEUROBIOLOGY 2021; 2:100022. [PMID: 36246504 PMCID: PMC9559952 DOI: 10.1016/j.crneur.2021.100022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/26/2021] [Accepted: 09/20/2021] [Indexed: 12/27/2022] Open
Abstract
A hippocampal-diencephalic-cortical network supports memory function. The anterior thalamic nuclei (ATN) form a key anatomical hub within this system. Consistent with this, injury to the mammillary body-ATN axis is associated with examples of clinical amnesia. However, there is only limited and indirect support that the output of ATN neurons actively enhances memory. Here, in rats, we first showed that mammillothalamic tract (MTT) lesions caused a persistent impairment in spatial working memory. MTT lesions also reduced rhythmic electrical activity across the memory system. Next, we introduced 8.5 Hz optogenetic theta-burst stimulation of the ATN glutamatergic neurons. The exogenously-triggered, regular pattern of stimulation produced an acute and substantial improvement of spatial working memory in rats with MTT lesions and enhanced rhythmic electrical activity. Neither behaviour nor rhythmic activity was affected by endogenous stimulation derived from the dorsal hippocampus. Analysis of immediate early gene activity, after the rats foraged for food in an open field, showed that exogenously-triggered ATN stimulation also increased Zif268 expression across memory-related structures. These findings provide clear evidence that increased ATN neuronal activity supports memory. They suggest that ATN-focused gene therapy may be feasible to counter clinical amnesia associated with dysfunction in the mammillary body-ATN axis. The mammillothalamic tract (MTT) supports neural activity in an extended memory system. Optogenetic activation of neurons in the anterior thalamus acutely improves memory after MTT lesions. Rescued memory associates with system-wide neuronal activation and enhanced EEG. Anterior thalamus actively sustains memory and is a feasible therapeutic target.
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24
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Mathiasen ML, O'Mara SM, Aggleton JP. The anterior thalamic nuclei and nucleus reuniens: So similar but so different. Neurosci Biobehav Rev 2020; 119:268-280. [PMID: 33069688 PMCID: PMC7738755 DOI: 10.1016/j.neubiorev.2020.10.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/26/2020] [Accepted: 10/05/2020] [Indexed: 12/04/2022]
Abstract
Two thalamic sites are of especial significance for understanding hippocampal - diencephalic interactions: the anterior thalamic nuclei and nucleus reuniens. Both nuclei have dense, direct interconnections with the hippocampal formation, and both are directly connected with many of the same cortical and subcortical areas. These two thalamic sites also contain neurons responsive to spatial stimuli while lesions within these two same areas can disrupt spatial learning tasks that are hippocampal dependent. Despite these many similarities, closer analysis reveals important differences in the details of their connectivity and the behavioural impact of lesions in these two thalamic sites. These nuclei play qualitatively different roles that largely reflect the contrasting relative importance of their medial frontal cortex interactions (nucleus reuniens) compared with their retrosplenial, cingulate, and mammillary body interactions (anterior thalamic nuclei). While the anterior thalamic nuclei are critical for multiple aspects of hippocampal spatial encoding and performance, nucleus reuniens contributes, as required, to aid cognitive control and help select correct from competing memories.
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Affiliation(s)
- Mathias L Mathiasen
- School of Psychology, Cardiff University, 70 Park Place, Cardiff, CF10 3AT, Wales, UK
| | - Shane M O'Mara
- School of Psychology and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - John P Aggleton
- School of Psychology, Cardiff University, 70 Park Place, Cardiff, CF10 3AT, Wales, UK.
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25
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Geier KT, Buchsbaum BR, Parimoo S, Olsen RK. The role of anterior and medial dorsal thalamus in associative memory encoding and retrieval. Neuropsychologia 2020; 148:107623. [DOI: 10.1016/j.neuropsychologia.2020.107623] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 09/04/2020] [Accepted: 09/06/2020] [Indexed: 02/06/2023]
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26
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Deconstructing the Direct Reciprocal Hippocampal-Anterior Thalamic Pathways for Spatial Learning. J Neurosci 2020; 40:6978-6990. [PMID: 32753513 PMCID: PMC7470921 DOI: 10.1523/jneurosci.0874-20.2020] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/14/2020] [Accepted: 07/19/2020] [Indexed: 01/13/2023] Open
Abstract
The hippocampus is essential for normal memory but does not act in isolation. The anterior thalamic nuclei may represent one vital partner. Using DREADDs, the behavioral consequences of transiently disrupting anterior thalamic function were examined, followed by inactivation of the dorsal subiculum. Next, the anterograde transport of an adeno-associated virus expressing DREADDs was paired with localized intracerebral infusions of a ligand to target specific input pathways. In this way, the direct projections from the anterior thalamic nuclei to the dorsal hippocampal formation were inhibited, followed by separate inhibition of the dorsal subiculum projections to the anterior thalamic nuclei. To assay spatial working memory, all animals performed a reinforced T-maze alternation task, then a more challenging version that nullifies intramaze cues. Across all four experiments, deficits emerged on the spatial alternation task that precluded the use of intramaze cues. Inhibiting dorsal subiculum projections to the anterior thalamic nuclei produced the severest spatial working memory deficit. This deficit revealed the key contribution of dorsal subiculum projections to the anteromedial and anteroventral thalamic nuclei for the processing of allocentric information, projections not associated with head-direction information. The overall pattern of results provides consistent causal evidence of the two-way functional significance of direct hippocampal-anterior thalamic interactions for spatial processing. At the same time, these findings are consistent with hypotheses that these same, reciprocal interactions underlie the common core symptoms of temporal lobe and diencephalic anterograde amnesia. SIGNIFICANCE STATEMENT It has long been conjectured that the anterior thalamic nuclei might be key partners with the hippocampal formation and that, respectively, they are principally responsible for diencephalic and temporal lobe amnesia. However, direct causal evidence for this functional relationship is lacking. Here, we examined the behavioral consequences of transiently silencing the direct reciprocal interconnections between these two brain regions on tests of spatial learning. Disrupting information flow from the hippocampal formation to the anterior thalamic nuclei and vice versa impaired performance on tests of spatial learning. By revealing the conjoint importance of hippocampal-anterior thalamic pathways, these findings help explain why pathology in either the medial diencephalon or the medial temporal lobes can result in profound anterograde amnesic syndromes.
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27
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Lu J, Yuan L, Jin J, Yang S, Zhang W, Li M, Zhang X, Wang J, Wu S, Chen Q, Qing Z, Dai Y, Zhang B, Wang Z. Brain Cortical Complexity and Subcortical Morphometrics in Lifelong Premature Ejaculation. Front Hum Neurosci 2020; 14:283. [PMID: 32792928 PMCID: PMC7387657 DOI: 10.3389/fnhum.2020.00283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/24/2020] [Indexed: 01/23/2023] Open
Abstract
Premature ejaculation (PE) is the most common male sexual dysfunction. The brain disturbances that cause this disorder remain poorly understood. This study aimed to investigate how the morphology of cortical and subcortical brain structures differed in PE, how these morphologic differences were associated with severity measures of PE, such as intravaginal ejaculatory latency time (IELT), and how these cortical and subcortical structures were causally connected through mediation analysis. Anatomical MRI scans were acquired from 39 male participants, 23 with PE (28.78 ± 4.32 years), and 16 without PE (27.88 ± 3.65 years). We used a subcortical analysis package within FSL to perform subcortical shape segmentation and statistical analysis. The PE group was compared with the normal control (NC) group in the shapes of 15 subcortical structures with general linear models [p < 0.05, family-wise error (FWE)-corrected]. We analyzed the cortical complexity revealed by the gyrification index using the Computational Anatomy Toolbox (CAT12). Vertex-wise shape analyses revealed outward shape deformations (expansions) in the left hippocampus and bilateral thalamus. Gyrification index analyses revealed that the right orbital frontal cortex and the right nucleus accumbens had greater complexity in PE patients. The shape deformations were positively correlated with the IELTs in the NC group, while this relationship was interrupted in the PE group. PE is associated with outward deformations of the subcortical surfaces and more complexity of the cortical structures. These morphological differences may be the basis of the brain functional alterations underlying PE.
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Affiliation(s)
- Jiaming Lu
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Lihua Yuan
- Department of Radiology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Jiaxuan Jin
- Department of Radiology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Shangwen Yang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Wen Zhang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Ming Li
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Xin Zhang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Junxia Wang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Sichu Wu
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Qian Chen
- Department of Radiology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Zhao Qing
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.,Institute of Brain Science, Nanjing University, Nanjing, China
| | - Yutian Dai
- Department of Andrology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Bing Zhang
- Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.,Department of Radiology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China.,Institute of Brain Science, Nanjing University, Nanjing, China
| | - Zhishun Wang
- Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
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Lu J, Bao W, Li M, Li L, Zhang Z, Alberts I, Brendel M, Cumming P, Lu H, Xiao Z, Zuo C, Guan Y, Zhao Q, Rominger A. Associations of [ 18F]-APN-1607 Tau PET Binding in the Brain of Alzheimer's Disease Patients With Cognition and Glucose Metabolism. Front Neurosci 2020; 14:604. [PMID: 32694971 PMCID: PMC7338611 DOI: 10.3389/fnins.2020.00604] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 05/18/2020] [Indexed: 11/16/2022] Open
Abstract
Molecular imaging of tauopathies is complicated by the differing specificities and off-target binding properties of available radioligands for positron emission tomography (PET). [18F]-APN-1607 ([18F]-PM-PBB3) is a newly developed PET tracer with promising properties for tau imaging. We aimed to characterize the cerebral binding of [18F]-APN-1607 in Alzheimer's disease (AD) patients compared to normal control (NC) subjects. Therefore, we obtained static late frame PET recordings with [18F]-APN-1607 and [18F]-FDG in patients with a clinical diagnosis of AD group, along with an age-matched NC group ([18F]-APN-1607 only). Using statistical parametric mapping (SPM) and volume of interest (VOI) analyses of the reference region normalized standardized uptake value ratio maps, we then tested for group differences and relationships between both PET biomarkers, as well as their associations with clinical general cognition. In the AD group, [18F]-APN-1607 binding was elevated in widespread cortical regions (P < 0.001 for VOI analysis, familywise error-corrected P < 0.01 for SPM analysis). The regional uptake in AD patients correlated negatively with Mini-Mental State Examination score (frontal lobe: R = -0.632, P = 0.004; temporal lobe: R = -0.593, P = 0.008; parietal lobe: R = -0.552, P = 0.014; insula: R = -0.650, P = 0.003; cingulum: R = -0.665, P = 0.002) except occipital lobe (R = -0.417, P = 0.076). The hypometabolism to [18F]-FDG PET in AD patients also showed negative correlations with regional [18F]-APN-1607 binding in some signature areas of AD (temporal lobe: R = -0.530, P = 0.020; parietal lobe: R = -0.637, P = 0.003; occipital lobe: R = -0.567, P = 0.011). In conclusion, our results suggested that [18F]-APN-1607 PET sensitively detected tau deposition in AD and that individual tauopathy correlated with impaired cerebral glucose metabolism and cognitive function.
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Affiliation(s)
- Jiaying Lu
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Weiqi Bao
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ming Li
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ling Li
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhengwei Zhang
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Ian Alberts
- Department of Nuclear Medicine, University Hospital Bern, Bern, Switzerland
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, Ludwig Maximilian University of Munich, Munich, Germany
| | - Paul Cumming
- Department of Nuclear Medicine, University Hospital Bern, Bern, Switzerland
- Faculty of Health, School of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia
| | - Huimeng Lu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhenxu Xiao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chuantao Zuo
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Qianhua Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Axel Rominger
- Department of Nuclear Medicine, University Hospital Bern, Bern, Switzerland
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Tay J, Lisiecka-Ford DM, Hollocks MJ, Tuladhar AM, Barrick TR, Forster A, O'Sullivan MJ, Husain M, de Leeuw FE, Morris RG, Markus HS. Network neuroscience of apathy in cerebrovascular disease. Prog Neurobiol 2020; 188:101785. [PMID: 32151533 DOI: 10.1016/j.pneurobio.2020.101785] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 02/26/2020] [Accepted: 03/03/2020] [Indexed: 01/15/2023]
Abstract
Apathy is a reduction in motivated goal-directed behavior (GDB) that is prevalent in cerebrovascular disease, providing an important opportunity to study the mechanistic underpinnings of motivation in humans. Focal lesions, such as those seen in stroke, have been crucial in developing models of brain regions underlying motivated behavior, while studies of cerebral small vessel disease (SVD) have helped define the connections between brain regions supporting such behavior. However, current lesion-based models cannot fully explain the neurobiology of apathy in stroke and SVD. To address this, we propose a network-based model which conceptualizes apathy as the result of damage to GDB-related networks. A review of the current evidence suggests that cerebrovascular disease-related pathology can lead to network changes outside of initially damaged territories, which may propagate to regions that share structural or functional connections. The presentation and longitudinal trajectory of apathy in stroke and SVD may be the result of these network changes. Distinct subnetworks might support cognitive components of GDB, the disruption of which results in specific symptoms of apathy. This network-based model of apathy may open new approaches for investigating its underlying neurobiology, and presents novel opportunities for its diagnosis and treatment.
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Affiliation(s)
- Jonathan Tay
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
| | | | - Matthew J Hollocks
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Anil M Tuladhar
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Thomas R Barrick
- Neuroscience Research Centre, Molecular and Clinical Sciences Research Institute, St. George's University of London, London, UK
| | - Anne Forster
- Academic Unit of Elderly Care and Rehabilitation, University of Leeds, Leeds, UK
| | - Michael J O'Sullivan
- University of Queensland Centre for Clinical Research, University of Queensland Australia, Brisbane, Australia
| | - Masud Husain
- Nuffield Department of Clinical Neurosciences & Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Frank-Erik de Leeuw
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Robin G Morris
- Department of Psychology, King's College London, London, UK
| | - Hugh S Markus
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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30
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St-Laurent M, Rosenbaum RS, Olsen RK, Buchsbaum BR. Representation of viewed and recalled film clips in patterns of brain activity in a person with developmental amnesia. Neuropsychologia 2020; 142:107436. [PMID: 32194085 DOI: 10.1016/j.neuropsychologia.2020.107436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 02/03/2020] [Accepted: 03/10/2020] [Indexed: 01/29/2023]
Abstract
As clear memories transport us back into the past, the brain also revives prior patterns of neural activity, a phenomenon known as neural reactivation. While growing evidence indicates a link between neural reactivation and typical variations in memory performance in healthy individuals, it is unclear how and to what extent reactivation is disrupted by a memory disorder. The current study characterizes neural reactivation in a case of amnesia using Multivoxel Pattern Analysis (MVPA). We tested NC, an individual with developmental amnesia linked to a diencephalic stroke, and 19 young adult controls on a functional magnetic resonance imaging (fMRI) task during which participants viewed and recalled short videos multiple times. An encoding classifier trained and tested to identify videos based on brain activity patterns elicited at perception revealed superior classification in NC. The enhanced consistency in stimulus representation we observed in NC at encoding was accompanied by an absence of multivariate repetition suppression, which occurred over repeated viewing in the controls. Another recall classifier trained and tested to identify videos during mental replay indicated normal levels of classification in NC, despite his poor memory for stimulus content. However, a cross-condition classifier trained on perception trials and tested on mental replay trials-a strict test of reactivation-revealed significantly poorer classification in NC. Thus, while NC's brain activity was consistent and stimulus-specific during mental replay, this specificity did not reflect the reactivation of patterns elicited at perception to the same extent as controls. Fittingly, we identified brain regions for which activity supported stimulus representation during mental replay to a greater extent in NC than in controls. This activity was not modeled on perception, suggesting that compensatory patterns of representation based on generic knowledge can support consistent mental constructs when memory is faulty. Our results reveal several ways in which amnesia impacts distributed patterns of stimulus representation during encoding and retrieval.
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Affiliation(s)
- Marie St-Laurent
- Rotman Research Institute at Baycrest, 3560 Bathurst Street, Toronto, Ontario, M6A 2E1, Canada.
| | - R Shayna Rosenbaum
- Rotman Research Institute at Baycrest, 3560 Bathurst Street, Toronto, Ontario, M6A 2E1, Canada; Department of Psychology, York University, Faculty of Health, Behavioural Sciences Building, 4700 Keele Street, Toronto, Ontario, M3J 1P3, Canada
| | - Rosanna K Olsen
- Rotman Research Institute at Baycrest, 3560 Bathurst Street, Toronto, Ontario, M6A 2E1, Canada; Department of Psychology, University of Toronto, 100 St.George Street, 4th Floor, Toronto, ON, M5S 3G3, Canada
| | - Bradley R Buchsbaum
- Rotman Research Institute at Baycrest, 3560 Bathurst Street, Toronto, Ontario, M6A 2E1, Canada; Department of Psychology, University of Toronto, 100 St.George Street, 4th Floor, Toronto, ON, M5S 3G3, Canada
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31
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Segobin S, Laniepce A, Ritz L, Lannuzel C, Boudehent C, Cabé N, Urso L, Vabret F, Eustache F, Beaunieux H, Pitel AL. Dissociating thalamic alterations in alcohol use disorder defines specificity of Korsakoff's syndrome. Brain 2020; 142:1458-1470. [PMID: 30879030 DOI: 10.1093/brain/awz056] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/23/2018] [Accepted: 01/20/2019] [Indexed: 12/25/2022] Open
Abstract
The thalamus, a relay organ consisting of several nuclei, is shared between the frontocerebellar circuit and the Papez circuit, both particularly affected in alcohol use disorder. Shrinkage of the thalamus is known to be more severe in alcoholics with Korsakoff's syndrome than in those without neurological complications (uncomplicated alcoholics). While thalamic atrophy could thus be a key factor explaining amnesia in Korsakoff's syndrome, the loci and nature of alterations within the thalamic nuclei in uncomplicated alcoholics and alcoholics with Korsakoff's syndrome remains unclear. Indeed, the literature from animal and human models is disparate regarding whether the anterior thalamic nuclei, or the mediodorsal nuclei are particularly affected and would be responsible for amnesia. Sixty-two participants (20 healthy controls, 26 uncomplicated alcoholics and 16 patients with Korsakoff's syndrome) underwent a diffusion tensor imaging sequence and T1-weighted MRI. State-of-the-art probabilistic tractography was used to segment the thalamus according to its connections to the prefrontal cortex and cerebellar Cruses I and II for the frontocerebellar circuit's executive loop, the precentral gyrus and cerebellar lobes IV-VI for the frontocerebellar circuit's motor loop, and hippocampus for the Papez circuit. The connectivity and volumes of these parcellations were calculated. Tractography showed that the hippocampus was principally connected to the anterior thalamic nuclei while the prefrontal cortex was principally connected to the mediodorsal nuclei. The fibre pathways connecting these brain regions and their respective thalamic nuclei have also been validated. ANCOVA, with age and gender as covariates, on connectivity measures showed abnormalities in both patient groups for thalamic parcellations connected to the hippocampus only [F(2,57) = 12.1; P < 0.0001; η2 = 0.2964; with graded effects of the number of connections from controls to uncomplicated alcoholics to Korsakoff's syndrome]. Atrophy, on the other hand, was observed for the prefrontal parcellation in both patient groups and to the same extent compared to controls [F(2,56) = 18.7; P < 0.0001; η2 = 0.40]. For the hippocampus parcellation, atrophy was found in the Korsakoff's syndrome group only [F(2,56) = 5.5; P = 0.006; η2 = 0.170, corrected for multiple comparisons using Bonferroni, P < 0.01]. Post hoc Tukey's test for unequal sample sizes, healthy controls > patients with Korsakoff's syndrome (P = 0.0036). Two different mechanisms seem to affect the thalamus. In the frontocerebellar circuit, atrophy of the mediodorsal nuclei may lead to the alterations, whereas in the Papez circuit, disconnection between the anterior nuclei and hippocampus may be the leading factor. Shrinkage of the anterior nuclei could be specific to patients with Korsakoff's syndrome, hence a potential neuroimaging marker of its pathophysiology, or more generally of thalamic amnesia for which Korsakoff's syndrome has historically been used as a model.
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Affiliation(s)
- Shailendra Segobin
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France
| | - Alice Laniepce
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France
| | - Ludivine Ritz
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France
| | - Coralie Lannuzel
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France
| | - Céline Boudehent
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France.,Service d'Addictologie, Centre Hospitalier Universitaire de Caen, Caen, France
| | - Nicolas Cabé
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France.,Service d'Addictologie, Centre Hospitalier Universitaire de Caen, Caen, France
| | - Laurent Urso
- Service d'Addictologie, Centre Hospitalier Roubaix, Roubaix, France
| | - François Vabret
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France.,Service d'Addictologie, Centre Hospitalier Universitaire de Caen, Caen, France
| | - Francis Eustache
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France
| | - Hélène Beaunieux
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France
| | - Anne-Lise Pitel
- Normandie Univ, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Cyceron, Neuropsychologie et Imagerie de la Mémoire Humaine, Caen, France
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32
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Refining the bigger picture: On the integrative memory model. Behav Brain Sci 2020; 42:e282. [PMID: 31896352 DOI: 10.1017/s0140525x19001791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The integrative memory model contains multiple subsystems. In this commentary, the processes within these subsystems are questioned. First, the assumption that familiarity largely reflects perceptual fluency is examined. Next, the distinction between "process" and "representational" models of temporal lobe function is challenged. Finally, the "relational representation core system" (or "extended hippocampal system"), which is central to the model, is especially sketchy. Here, I highlight key questions to be addressed in order to understand this system's role in trace formation.
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Zhao J, Su Q, Liu F, Zhang Z, Yang R, Guo W, Zhao J. Enhanced Connectivity of Thalamo-Cortical Networks in First-Episode, Treatment-Naive Somatization Disorder. Front Psychiatry 2020; 11:555836. [PMID: 33061917 PMCID: PMC7518236 DOI: 10.3389/fpsyt.2020.555836] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 08/18/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Dysfunctions of the thalamus and its projections to cortical cortices have been implicated in patient with somatization disorder (SD). However, changes in the anatomical specificity of thalamo-cortical functional connectivity (FC) in SD remain unclear. METHODS Resting-state fMRI scans were collected in 25 first-episode, drug-naive patients with SD, as well as 28 sex-, age-, and education-matched healthy controls. We parcellated the thalamus with seven predefined regions of interest (ROIs) and used them as seeds to map whole-brain FC. Correlation analysis was conducted in the patients. RESULTS We found an increased pattern of thalamic ROI-cortex connectivity in patients with SD. Patients with SD demonstrated enhanced thalamic connectivity to the bilateral anterior/middle cingulum, motor/sensory cortex, visual cortex, and auditory cortex. A significantly negative correlation was found between the right occipital thalamic ROI to the anterior cingulum and EPQ extraversion scores (r=0.404, p=0.045) after the Benjamini-Hochberg correction. CONCLUSIONS This study demonstrates that anatomical specificity of enhanced thalamo-cortical FCs exists in first-episode, drug-naive patients with SD. These findings further highlight the importance of the thalamic subregions in the pathophysiology of SD.
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Affiliation(s)
- Jin Zhao
- National Clinical Research Center for Mental Disorders, and Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China.,Department of Psychiatry, Henan Mental Hospital, Second Affiliated Hospital of Xinxiang Medical University, Xinxiang, China
| | - Qinji Su
- Mental Health Center, the Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Feng Liu
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Zhikun Zhang
- Mental Health Center, the Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ru Yang
- Department of Radiology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Wenbin Guo
- National Clinical Research Center for Mental Disorders, and Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China.,Department of Psychiatry, The Third People's Hospital of Foshan, Foshan, China
| | - Jingping Zhao
- National Clinical Research Center for Mental Disorders, and Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
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34
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Coad BM, Craig E, Louch R, Aggleton JP, Vann SD, Metzler-Baddeley C. Precommissural and postcommissural fornix microstructure in healthy aging and cognition. Brain Neurosci Adv 2020; 4:2398212819899316. [PMID: 32219177 PMCID: PMC7085915 DOI: 10.1177/2398212819899316] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 12/11/2019] [Indexed: 11/23/2022] Open
Abstract
The fornix is a key tract of the hippocampal formation, whose status is presumed to contribute to age-related cognitive decline. The precommissural and postcommissural fornix subdivisions form respective basal forebrain/frontal and diencephalic networks that may differentially affect aging and cognition. We employed multi-parametric magnetic resonance imaging (MRI) including neurite orientation density and dispersion imaging, quantitative magnetization transfer (qMT), and T1-relaxometry MRI to investigate the microstructural properties of these fornix subdivisions and their relationship with aging and cognition in 149 asymptomatic participants (38-71 years). Aging was associated with increased free water signal and reductions in myelin-sensitive R1 and qMT indices but no apparent axon density differences in both precommissural and postcommissural fibers. Precommissural relative to postcommissural fibers showed a distinct microstructural pattern characterised by larger free water signal and axon orientation dispersion, with lower apparent myelin and axon density. Furthermore, differences in postcommissural microstructure were related to performance differences in object-location paired-associate learning. These results provide novel in vivo neuroimaging evidence for distinct microstructural properties of precommissural and postcommissural fibers that are consistent with their anatomy as found in axonal tracer studies, as well as for a contribution of postcommissural fibers to the learning of spatial configurations.
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Affiliation(s)
- Bethany M. Coad
- Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff, UK
- School of Psychology, Cardiff University, Cardiff, UK
| | - Emma Craig
- School of Psychology, Cardiff University, Cardiff, UK
| | - Rebecca Louch
- School of Psychology, Cardiff University, Cardiff, UK
| | | | | | - Claudia Metzler-Baddeley
- Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff, UK
- School of Psychology, Cardiff University, Cardiff, UK
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35
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Mathiasen ML, Louch RC, Nelson AD, Dillingham CM, Aggleton JP. Trajectory of hippocampal fibres to the contralateral anterior thalamus and mammillary bodies in rats, mice, and macaque monkeys. Brain Neurosci Adv 2019; 3:2398212819871205. [PMID: 31588413 PMCID: PMC6712910 DOI: 10.1177/2398212819871205] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 07/26/2019] [Indexed: 11/17/2022] Open
Abstract
The routes by which the hippocampal formation projects bilaterally to the anterior thalamic nuclei and mammillary bodies were examined in the mouse, rat, and macaque monkey. Despite using different methods and different species, the principal pattern remained the same. For both target areas, the contralateral hippocampal (subiculum) projections arose via efferents in the postcommissural fornix ipsilateral to the tracer injection, which then crossed hemispheres both in or just prior to reaching the target site within the thalamus or hypothalamus. Precommissural fornix fibres could not be followed to the target areas. There was scant evidence that the ventral hippocampal commissure or decussating fornix fibres contribute to these crossed subiculum projections. Meanwhile, a small minority of postsubiculum projections in the mouse were seen to cross in the descending fornix at the level of the caudal septum to join the contralateral postcommissural fornix before reaching the anterior thalamus and lateral mammillary nucleus on that side. Although the rodent anterior thalamic nuclei also receive nonfornical inputs from the subiculum and postsubiculum via the ipsilateral internal capsule, few, if any, of these projections cross the midline. It was also apparent that nuclei within the head direction system (anterodorsal thalamic nucleus, laterodorsal thalamic nucleus, and lateral mammillary nucleus) receive far fewer crossed hippocampal inputs than the other anterior thalamic or mammillary nuclei. The present findings increase our understanding of the fornix and its component pathways while also informing disconnection analyses involving the hippocampal formation and diencephalon.
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36
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Dillingham CM, Milczarek MM, Perry JC, Frost BE, Parker GD, Assaf Y, Sengpiel F, O'Mara SM, Vann SD. Mammillothalamic Disconnection Alters Hippocampocortical Oscillatory Activity and Microstructure: Implications for Diencephalic Amnesia. J Neurosci 2019; 39:6696-6713. [PMID: 31235646 PMCID: PMC6703878 DOI: 10.1523/jneurosci.0827-19.2019] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/08/2019] [Accepted: 06/10/2019] [Indexed: 01/13/2023] Open
Abstract
Diencephalic amnesia can be as debilitating as the more commonly known temporal lobe amnesia, yet the precise contribution of diencephalic structures to memory processes remains elusive. Across four cohorts of male rats, we used discrete lesions of the mammillothalamic tract to model aspects of diencephalic amnesia and assessed the impact of these lesions on multiple measures of activity and plasticity within the hippocampus and retrosplenial cortex. Lesions of the mammillothalamic tract had widespread indirect effects on hippocampocortical oscillatory activity within both theta and gamma bands. Both within-region oscillatory activity and cross-regional synchrony were altered. The network changes were state-dependent, displaying different profiles during locomotion and paradoxical sleep. Consistent with the associations between oscillatory activity and plasticity, complementary analyses using several convergent approaches revealed microstructural changes, which appeared to reflect a suppression of learning-induced plasticity in lesioned animals. Together, these combined findings suggest a mechanism by which damage to the medial diencephalon can impact upon learning and memory processes, highlighting an important role for the mammillary bodies in the coordination of hippocampocortical activity.SIGNIFICANCE STATEMENT Information flow within the Papez circuit is critical to memory. Damage to ascending mammillothalamic projections has consistently been linked to amnesia in humans and spatial memory deficits in animal models. Here we report on the changes in hippocampocortical oscillatory dynamics that result from chronic lesions of the mammillothalamic tract and demonstrate, for the first time, that the mammillary bodies, independently of the supramammillary region, contribute to frequency modulation of hippocampocortical theta oscillations. Consistent with the associations between oscillatory activity and plasticity, the lesions also result in a suppression of learning-induced plasticity. Together, these data support new functional models whereby mammillary bodies are important for coordinating hippocampocortical activity rather than simply being a relay of hippocampal information as previously assumed.
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Affiliation(s)
- Christopher M Dillingham
- School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Michal M Milczarek
- School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom
| | - James C Perry
- School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom
| | - Bethany E Frost
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Greg D Parker
- EMRIC, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Yaniv Assaf
- George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel 6997801, and
| | - Frank Sengpiel
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom
| | - Shane M O'Mara
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Seralynne D Vann
- School of Psychology, Cardiff University, Cardiff CF10 3AT, United Kingdom,
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O’Mara SM, Aggleton JP. Space and Memory (Far) Beyond the Hippocampus: Many Subcortical Structures Also Support Cognitive Mapping and Mnemonic Processing. Front Neural Circuits 2019; 13:52. [PMID: 31447653 PMCID: PMC6692652 DOI: 10.3389/fncir.2019.00052] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 07/22/2019] [Indexed: 11/13/2022] Open
Abstract
Memory research remains focused on just a few brain structures-in particular, the hippocampal formation (the hippocampus and entorhinal cortex). Three key discoveries promote this continued focus: the striking demonstrations of enduring anterograde amnesia after bilateral hippocampal damage; the realization that synapses in the hippocampal formation are plastic e.g., when responding to short bursts of patterned stimulation ("long-term potentiation" or LTP); and the discovery of a panoply of spatially-tuned cells, principally surveyed in the hippocampal formation (place cells coding for position; head-direction cells, providing compass-like information; and grid cells, providing a metric for 3D space). Recent anatomical, behavioral, and electrophysiological work extends this picture to a growing network of subcortical brain structures, including the anterior thalamic nuclei, rostral midline thalamic nuclei, and the claustrum. There are, for example, spatially-tuned cells in all of these regions, including cells with properties similar to place cells of the hippocampus proper. These findings add new perspectives to what had been originally been proposed-but often overlooked-half a century ago: that damage to an extended network of structures connected to the hippocampal formation results in diencephalic amnesia. We suggest these new findings extend spatial signaling in the brain far beyond the hippocampal formation, with profound implications for theories of the neural bases of spatial and mnemonic functions.
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Affiliation(s)
- Shane M. O’Mara
- School of Psychology and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - John P. Aggleton
- School of Psychology, Cardiff University, Cardiff, United Kingdom
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38
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Argyropoulos GPD, Loane C, Roca-Fernandez A, Lage-Martinez C, Gurau O, Irani SR, Butler CR. Network-wide abnormalities explain memory variability in hippocampal amnesia. eLife 2019; 8:e46156. [PMID: 31282861 PMCID: PMC6639076 DOI: 10.7554/elife.46156] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 07/05/2019] [Indexed: 01/11/2023] Open
Abstract
Patients with hippocampal amnesia play a central role in memory neuroscience but the neural underpinnings of amnesia are hotly debated. We hypothesized that focal hippocampal damage is associated with changes across the extended hippocampal system and that these, rather than hippocampal atrophy per se, would explain variability in memory between patients. We assessed this hypothesis in a uniquely large cohort of patients (n = 38) after autoimmune limbic encephalitis, a syndrome associated with focal structural hippocampal pathology. These patients showed impaired recall, recognition and maintenance of new information, and remote autobiographical amnesia. Besides hippocampal atrophy, we observed correlatively reduced thalamic and entorhinal cortical volume, resting-state inter-hippocampal connectivity and activity in posteromedial cortex. Associations of hippocampal volume with recall, recognition, and remote memory were fully mediated by wider network abnormalities, and were only direct in forgetting. Network abnormalities may explain the variability across studies of amnesia and speak to debates in memory neuroscience.
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Affiliation(s)
- Georgios PD Argyropoulos
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Clare Loane
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUnited Kingdom
| | - Adriana Roca-Fernandez
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Carmen Lage-Martinez
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
- Valdecilla Biomedical Research InstituteUniversity Hospital Marqués de ValdecillaSantanderSpain
| | - Oana Gurau
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Christopher R Butler
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
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Perry BAL, Mitchell AS. Considering the Evidence for Anterior and Laterodorsal Thalamic Nuclei as Higher Order Relays to Cortex. Front Mol Neurosci 2019; 12:167. [PMID: 31333412 PMCID: PMC6616498 DOI: 10.3389/fnmol.2019.00167] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Accepted: 06/17/2019] [Indexed: 12/25/2022] Open
Abstract
Our memories are essential in our daily lives. The frontal and cingulate cortices, hippocampal system and medial temporal lobes are key brain regions. In addition, severe amnesia also occurs after damage or dysfunction to the anterior thalamic nuclei; this subcortical thalamic hub is interconnected to these key cortical memory structures. Behavioral, anatomical, and physiological evidence across mammalian species has shown that interactions between the anterior thalamic nuclei, cortex and hippocampal formation are vital for spatial memory processing. Furthermore, the adjacent laterodorsal thalamic nucleus (LD), interconnected to the retrosplenial cortex (RSC) and visual system, also contributes to spatial memory in mammals. However, how these thalamic nuclei contribute to memory still remains largely unknown. Fortunately, our understanding of the importance of the thalamus in cognitive processes is being redefined, as widespread evidence challenges the established view of the thalamus as a passive relay of sensory and subcortical information to the cortex. In this review article, we examine whether the anterior thalamic nuclei and the adjacent LD are suitable candidates for "higher-order" thalamic nuclei, as defined by the Sherman and Guillery model. Rather than simply relaying information to cortex, "higher-order" thalamic nuclei have a prominent role in cognition, as they can regulate how areas of the cortex interact with one another. These considerations along with a review of the latest research will be used to suggest future studies that will clarify the contributions that the anterior and LD have in supporting cortical functions during cognitive processes.
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Affiliation(s)
- Brook A L Perry
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Anna S Mitchell
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
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40
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Trojsi F, Caiazzo G, Siciliano M, Femiano C, Passaniti C, Russo A, Bisecco A, Monsurrò MR, Cirillo M, Esposito F, Tedeschi G, Santangelo G. Microstructural correlates of Edinburgh Cognitive and Behavioural ALS Screen (ECAS) changes in amyotrophic lateral sclerosis. Psychiatry Res Neuroimaging 2019; 288:67-75. [PMID: 30987770 DOI: 10.1016/j.pscychresns.2019.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 03/30/2019] [Accepted: 04/01/2019] [Indexed: 11/17/2022]
Abstract
Edinburgh Cognitive and Behavioural ALS Screen (ECAS) was designed for testing patients with amyotrophic lateral sclerosis (ALS), a multi-system neurodegenerative disease characterized by progressive physical disability. In this study, we aim to explore the potential brain microstructural substrates associated with performance on ECAS in the early stages of ALS, using a whole-brain tract-based spatial statistics diffusion tensor imaging approach. Thirty-six non-demented ALS patients, assessed using ECAS, and 35 age-, sex- and education-matched healthy controls underwent magnetic resonance imaging at 3 Tesla. The ALS patients showed decreased fractional anisotropy (FA) in the cortico-spinal tracts and corpus callosum (CC) and significant association between verbal fluency score, among ALS-specific ECAS scores, and FA measures in several long association fiber tracts in the frontal, temporal and parietal lobes. Furthermore, the ALS non-specific total score was inversely related to axial diffusivity (AD) in the mediodorsal nucleus of the thalamus, with more extended areas of correlation in the CC, when considering only the memory subscore. Our results point towards microstructural degeneration across motor and extra-motor areas in ALS, underlining that alterations in verbal fluency performances may be related to impairment of frontotemporal connectivity, while alterations of memory may be associated with damage of thalamocortical circuits.
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Affiliation(s)
- Francesca Trojsi
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy.
| | - Giuseppina Caiazzo
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy
| | - Mattia Siciliano
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy; Department of Psychology, University of Campania "Luigi Vanvitelli", Caserta, Italy
| | - Cinzia Femiano
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy
| | - Carla Passaniti
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy; Department of Psychology, University of Campania "Luigi Vanvitelli", Caserta, Italy
| | - Antonio Russo
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy
| | - Alvino Bisecco
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy
| | - Maria Rosaria Monsurrò
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy
| | - Mario Cirillo
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy
| | - Fabrizio Esposito
- Department of Medicine, Surgery and Dentistry, "Scuola Medica Salernitana" University of Salerno, Baronissi, Salerno, Italy
| | - Gioacchino Tedeschi
- Department of Advanced Medical and Surgical Sciences, MRI Research Centre "SUN-FISM", University of Campania "Luigi Vanvitelli", P.zza Miraglia 2, Naples 80138, Italy
| | - Gabriella Santangelo
- Department of Psychology, University of Campania "Luigi Vanvitelli", Caserta, Italy
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41
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Oedekoven CSH, Keidel JL, Anderson S, Nisbet A, Bird CM. Effects of amnesia on processing in the hippocampus and default mode network during a naturalistic memory task: A case study. Neuropsychologia 2019; 132:107104. [PMID: 31260681 DOI: 10.1016/j.neuropsychologia.2019.05.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 05/17/2019] [Accepted: 05/24/2019] [Indexed: 12/27/2022]
Abstract
Despite their severely impaired episodic memory, individuals with amnesia are able to comprehend ongoing events. Online representations of a current event are thought to be supported by a network of regions centred on the posterior midline cortex (PMC). By contrast, episodic memory is widely believed to be supported by interactions between the hippocampus and these cortical regions. In this MRI study, we investigated the encoding and retrieval of real life-like events (video clips) in a patient with severe amnesia likely resulting from a stroke to the right (and possibly the left) thalamus, and a group of 20 age-matched controls. Structural MRI revealed grey matter reductions in left hippocampus and left thalamus in comparison to controls. We first characterised the regions activated in the controls while they watched and retrieved the videos. There were no differences in activation between the patient and controls in any of the regions. We then identified a widespread network of brain regions, including the hippocampus, that were functionally connected with the PMC in controls. However, in the patient there was a specific reduction in functional connectivity between the PMC and a region of left hippocampus when both watching and attempting to retrieve the videos. A follow up analysis of the control group revealed that, when watching the videos, the functional connectivity between these two regions was correlated with memory performance. Taken together, these findings support the view that the interactions between the PMC and the hippocampus enable the encoding and retrieval of naturalistic events.
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Affiliation(s)
| | | | - Stuart Anderson
- Hurstwood Park Clinical Neurosciences Centre, Brighton & Sussex University Hospitals NHS Trust, UK
| | - Angus Nisbet
- Hurstwood Park Clinical Neurosciences Centre, Brighton & Sussex University Hospitals NHS Trust, UK.
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42
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Belkhiria C, Vergara RC, San Martín S, Leiva A, Marcenaro B, Martinez M, Delgado C, Delano PH. Cingulate Cortex Atrophy Is Associated With Hearing Loss in Presbycusis With Cochlear Amplifier Dysfunction. Front Aging Neurosci 2019; 11:97. [PMID: 31080411 PMCID: PMC6497796 DOI: 10.3389/fnagi.2019.00097] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 04/10/2019] [Indexed: 12/14/2022] Open
Abstract
Age-related hearing loss is associated with cognitive decline and has been proposed as a risk factor for dementia. However, the mechanisms that relate hearing loss to cognitive decline remain elusive. Here, we propose that the impairment of the cochlear amplifier mechanism is associated with structural brain changes and cognitive impairment. Ninety-six subjects aged over 65 years old (63 female and 33 male) were evaluated using brain magnetic resonance imaging, neuropsychological and audiological assessments, including distortion product otoacoustic emissions as a measure of the cochlear amplifier function. All the analyses were adjusted by age, gender and education. The group with cochlear amplifier dysfunction showed greater brain atrophy in the cingulate cortex and in the parahippocampus. In addition, the atrophy of the cingulate cortex was associated with cognitive impairment in episodic and working memories and in language and visuoconstructive abilities. We conclude that the neural abnormalities observed in presbycusis subjects with cochlear amplifier dysfunction extend beyond core auditory network and are associated with cognitive decline in multiple domains. These results suggest that a cochlear amplifier dysfunction in presbycusis is an important mechanism relating hearing impairments to brain atrophy in the extended network of effortful hearing.
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Affiliation(s)
- Chama Belkhiria
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Rodrigo C Vergara
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Simón San Martín
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Alexis Leiva
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Bruno Marcenaro
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Melissa Martinez
- Department of Neurology and Neurosurgery, Clinical Hospital of the University of Chile, Santiago, Chile
| | - Carolina Delgado
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago, Chile.,Department of Neurology and Neurosurgery, Clinical Hospital of the University of Chile, Santiago, Chile
| | - Paul H Delano
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago, Chile.,Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile.,Department of Otolaryngology, Clinical Hospital of the University of Chile, Santiago, Chile
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43
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Ding Y, Ou Y, Su Q, Pan P, Shan X, Chen J, Liu F, Zhang Z, Zhao J, Guo W. Enhanced Global-Brain Functional Connectivity in the Left Superior Frontal Gyrus as a Possible Endophenotype for Schizophrenia. Front Neurosci 2019; 13:145. [PMID: 30863277 PMCID: PMC6399149 DOI: 10.3389/fnins.2019.00145] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 02/08/2019] [Indexed: 01/04/2023] Open
Abstract
The notion of dysconnectivity in schizophrenia has been put forward for many years and results in substantial attempts to explore altered functional connectivity (FC) within different networks with inconsistent results. Clinical, demographical, and methodological heterogeneity may contribute to the inconsistency. Forty-four patients with first-episode, drug-naive schizophrenia, 42 unaffected siblings of schizophrenia patients and 44 healthy controls took part in this study. Global-brain FC (GFC) was employed to analyze the imaging data. Compared with healthy controls, patients with schizophrenia and unaffected siblings shared enhanced GFC in the left superior frontal gyrus (SFG). In addition, patients had increased GFC mainly in the thalamo-cortical network, including the bilateral thalamus, bilateral posterior cingulate cortex (PCC)/precuneus, left superior medial prefrontal cortex (MPFC), right angular gyrus, and right SFG/middle frontal gyrus and decreased GFC in the left ITG/cerebellum Crus I. No other altered GFC values were observed in the siblings group relative to the control group. Further ROC analysis showed that increased GFC in the left SFG could separate the patients or the siblings from the controls with acceptable sensitivities. Our findings suggest that increased GFC in the left SFG may serve as a potential endophenotype for schizophrenia.
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Affiliation(s)
- Yudan Ding
- Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Yangpan Ou
- Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Qinji Su
- Mental Health Center, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Pan Pan
- Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Xiaoxiao Shan
- Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Jindong Chen
- Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Feng Liu
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Zhikun Zhang
- Mental Health Center, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jingping Zhao
- Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Wenbin Guo
- Department of Psychiatry, The Second Xiangya Hospital of Central South University, Changsha, China
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44
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The Localization Research of Brain Plasticity Changes after Brachial Plexus Pain: Sensory Regions or Cognitive Regions? Neural Plast 2019; 2019:7381609. [PMID: 30728834 PMCID: PMC6341257 DOI: 10.1155/2019/7381609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/30/2018] [Accepted: 11/19/2018] [Indexed: 01/08/2023] Open
Abstract
Objective Neuropathic pain after brachial plexus injury remains an increasingly prevalent and intractable disease due to inadequacy of satisfactory treatment strategies. A detailed mapping of cortical regions concerning the brain plasticity was the first step of therapeutic intervention. However, the specific mapping research of brachial plexus pain was limited. We aimed to provide some localization information about the brain plasticity changes after brachial plexus pain in this preliminary study. Methods 24 Sprague-Dawley rats received complete brachial plexus avulsion with neuropathic pain on the right forelimb successfully. Through functional imaging of both resting-state and block-design studies, we compared the amplitude of low-frequency fluctuations (ALFF) of premodeling and postmodeling groups and the changes of brain activation when applying sensory stimulation. Results The postmodeling group showed significant decreases on the mechanical withdrawal threshold (MWT) in the bilateral hindpaws and thermal withdrawal latency (TWL) in the left hindpaw than the premodeling group (P < 0.05). The amplitude of low-frequency fluctuations (ALFF) of the postmodeling group manifested increases in regions of the left anterodorsal hippocampus, left mesencephalic region, left dorsal midline thalamus, and so on. Decreased ALFF was observed in the bilateral entorhinal cortex compared to that of the premodeling group. The results of block-design scan showed significant differences in regions including the limbic/paralimbic system and somatosensory cortex. Conclusion We concluded that the entorhinal-hippocampus pathway, which was part of the Papez circuit, was involved in the functional integrated areas of brachial plexus pain processing. The regions in the “pain matrix” showed expected activation when applying instant nociceptive stimulus but remained silent in the resting status. This research confirmed the involvement of cognitive function, which brought novel information to the potential new therapy for brachial plexus pain.
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45
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Phillips JM, Fish LR, Kambi NA, Redinbaugh MJ, Mohanta S, Kecskemeti SR, Saalmann YB. Topographic organization of connections between prefrontal cortex and mediodorsal thalamus: Evidence for a general principle of indirect thalamic pathways between directly connected cortical areas. Neuroimage 2019; 189:832-846. [PMID: 30711468 DOI: 10.1016/j.neuroimage.2019.01.078] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 01/13/2019] [Accepted: 01/30/2019] [Indexed: 02/02/2023] Open
Abstract
Our ability to act flexibly, according to goals and context, is known as cognitive control. Hierarchical levels of control, reflecting different levels of abstraction, are represented across prefrontal cortex (PFC). Although the mediodorsal thalamic nucleus (MD) is extensively interconnected with PFC, the role of MD in cognitive control is unclear. Tract tracer studies in macaques, involving subsets of PFC areas, have converged on coarse MD-PFC connectivity principles; but proposed finer-grained topographic schemes, which constrain interactions between MD and PFC, disagree in many respects. To investigate a unifying topographic scheme, we performed probabilistic tractography on diffusion MRI data from eight macaque monkeys, and estimated the probable paths connecting MD with each of all 19 architectonic areas of PFC. We found a connectional topography where the orderly progression from ventromedial to anterior to posterolateral PFC was represented from anteromedial to posterolateral MD. The projection zones of posterolateral PFC areas in MD showed substantial overlap, and those of ventral and anteromedial PFC areas in MD overlapped. The exception was cingulate area 24: its projection zone overlapped with projections zones of all other PFC areas. Overall, our data suggest that nearby, functionally related, directly connected PFC areas have partially overlapping projection zones in MD, consistent with a role for MD in coordinating communication across PFC. Indeed, the organizing principle for PFC projection zones in MD appears to reflect the flow of information across the hierarchical, multi-level PFC architecture. In addition, cingulate area 24 may have privileged access to influence thalamocortical interactions involving all other PFC areas.
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Affiliation(s)
- Jessica M Phillips
- Department of Psychology, University of Wisconsin-Madison, United States.
| | - Lesenia R Fish
- Department of Psychology, University of Wisconsin-Madison, United States
| | - Niranjan A Kambi
- Department of Psychology, University of Wisconsin-Madison, United States
| | | | - Sounak Mohanta
- Department of Psychology, University of Wisconsin-Madison, United States
| | - Steven R Kecskemeti
- Brain Imaging Core, Waisman Center, University of Wisconsin-Madison, United States
| | - Yuri B Saalmann
- Department of Psychology, University of Wisconsin-Madison, United States; Wisconsin National Primate Research Center, University of Wisconsin-Madison, United States.
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46
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Disrupted Resting-State Functional Connectivity in Hippocampal Subregions After Sleep Deprivation. Neuroscience 2019; 398:37-54. [DOI: 10.1016/j.neuroscience.2018.11.049] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 11/28/2018] [Accepted: 11/29/2018] [Indexed: 01/04/2023]
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47
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Hartopp N, Wright P, Ray NJ, Evans TE, Metzler-Baddeley C, Aggleton JP, O'Sullivan MJ. A Key Role for Subiculum-Fornix Connectivity in Recollection in Older Age. Front Syst Neurosci 2019; 12:70. [PMID: 30687030 PMCID: PMC6335321 DOI: 10.3389/fnsys.2018.00070] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 12/17/2018] [Indexed: 11/13/2022] Open
Abstract
Individual differences in memory during aging are associated with the microstructure of the fornix, a bidirectional tract connecting the hippocampus with the diencephalon, basal forebrain and cortex. To investigate the origin of alterations in fornix microstructure, measurement of hippocampal subfield volumes was combined with diffusion MRI and cognitive evaluation in a new sample of 31 healthy human participants aged 50-89 years. The fornix, uncinate and parahippocampal cingulum were reconstructed using diffusion MRI tractography. Episodic memory was assessed with free and cued verbal recall, visual recognition and paired associate learning tests. Recall performance was associated with fornix microstructure and hippocampal subfield volumes. Subiculum and CA1 volumes remained positively associated with fornix microstructure when controlling for other volumes. Subiculum volume was also associated with fornix microstructure independent of age. Regression analyses showed that subiculum-fornix associations explained more variation in recall than that of CA1-fornix associations. In a multivariable regression model, age and subiculum volume were independent predictors of free recall whilst fornix microstructure and CA1 volume were not. These results suggest that age-related changes in a network that includes the subiculum and fornix are important in cognitive change in healthy aging. These results match anatomical predictions concerning the importance of hippocampal - diencephalic projections for memory.
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Affiliation(s)
- Naomi Hartopp
- Division of Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Paul Wright
- Division of Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Nicola J Ray
- Department of Psychology, Manchester Metropolitan University, Manchester, United Kingdom
| | - Tavia E Evans
- Division of Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.,Department of Epidemiology, Erasmus Medical Center, Rotterdam, Netherlands
| | | | - John P Aggleton
- School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - Michael J O'Sullivan
- Division of Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.,School of Psychology, Cardiff University, Cardiff, United Kingdom.,Centre for Clinical Research, University of Queensland, Brisbane, QLD, Australia.,Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
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48
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Ulrich K, Spriggs MJ, Abraham WC, Dalrymple-Alford JC, McNaughton N. Environmental enrichment increases prefrontal EEG power and synchrony with the hippocampus in rats with anterior thalamus lesions. Hippocampus 2018; 29:128-140. [PMID: 30153381 DOI: 10.1002/hipo.23022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 07/11/2018] [Accepted: 08/14/2018] [Indexed: 11/12/2022]
Abstract
The anterior thalamic nuclei (ATN) are a major interface between the hippocampus and prefrontal cortex within an extended Papez circuit. Rat models suggest that the deficits caused by ATN damage, which is associated with "diencephalic amnesia", can be ameliorated by environmental enrichment (EE) through unknown mechanisms. We examined whether changes in theta rhythmicity within and between the hippocampus and prefrontal cortex are influenced by EE in rats with ATN lesions. Here, we show that ATN lesions and EE produced essentially opposed functional effects in terms of changes in rhythmicity between two consecutive trials when rats forage for chocolate hail. On the second trial, standard-housed rats with ATN lesions showed: (a) a clear reduction in prefrontal cortex experience-dependent power change in the theta band and in two adjacent bands; (b) little change in the theta band in hippocampal area CA1; and (c) only a modest overall reduction in experience-dependent power change at lower theta frequencies in the dentate gyrus. EE exposure prevented the decrease in prefrontal theta power in rats with ATN lesions, and in fact caused a clear increase in prefrontal cortex power across all bands. While ATN lesions did not reliably affect prefrontal-CA1 or prefrontal-dentate theta coherence, EE increased the coherence between prefrontal cortex and area CA1 in both the sham and ATN groups. Thus, EE increases functional connectivity between prefrontal cortex and hippocampus via pathways that bypass the ATN, and increases behaviorally dependent prefrontal rhythmicity. These EEG effects may contribute to improved learning and memory in the ATN-lesion model of diencephalic amnesia.
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Affiliation(s)
- Katharina Ulrich
- Department of Psychology and Brain Health Research Center, University of Otago, Dunedin, New Zealand
| | - Megg J Spriggs
- Department of Psychology, Brain Health Research Center, and Brain Research New Zealand, University of Otago, Dunedin, New Zealand.,School of Psychology, and Brain Research New Zealand, University of Auckland, Auckland, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Center, and Brain Research New Zealand, University of Otago, Dunedin, New Zealand
| | - John C Dalrymple-Alford
- Department of Psychology, New Zealand Brain Research Institute and Brain Research New Zealand, University of Canterbury, Ilam, Christchurch, New Zealand
| | - Neil McNaughton
- Department of Psychology and Brain Health Research Center, University of Otago, Dunedin, New Zealand
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Pergola G, Danet L, Pitel AL, Carlesimo GA, Segobin S, Pariente J, Suchan B, Mitchell AS, Barbeau EJ. The Regulatory Role of the Human Mediodorsal Thalamus. Trends Cogn Sci 2018; 22:1011-1025. [PMID: 30236489 PMCID: PMC6198112 DOI: 10.1016/j.tics.2018.08.006] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/31/2018] [Accepted: 08/17/2018] [Indexed: 12/17/2022]
Abstract
The function of the human mediodorsal thalamic nucleus (MD) has so far eluded a clear definition in terms of specific cognitive processes and tasks. Although it was at first proposed to play a role in long-term memory, a set of recent studies in animals and humans has revealed a more complex, and broader, role in several cognitive functions. The MD seems to play a multifaceted role in higher cognitive functions together with the prefrontal cortex and other cortical and subcortical brain areas. Specifically, we propose that the MD is involved in the regulation of cortical networks especially when the maintenance and temporal extension of persistent activity patterns in the frontal lobe areas are required.
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Affiliation(s)
- Giulio Pergola
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari Aldo Moro, Bari 70124, Italy.
| | - Lola Danet
- Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS 31024, France; CHU Toulouse Purpan, Neurology Department, Toulouse 31059, France
| | - Anne-Lise Pitel
- Normandie University, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Neuropsychologie et Imagerie de la Mémoire Humaine, 14000 Caen, France
| | - Giovanni A Carlesimo
- Department of Systems Medicine, Tor Vergata University and S. Lucia Foundation, Rome, Italy
| | - Shailendra Segobin
- Normandie University, UNICAEN, PSL Research University, EPHE, INSERM, U1077, CHU de Caen, Neuropsychologie et Imagerie de la Mémoire Humaine, 14000 Caen, France
| | - Jérémie Pariente
- Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS 31024, France; CHU Toulouse Purpan, Neurology Department, Toulouse 31059, France
| | - Boris Suchan
- Clinical Neuropsychology, Ruhr University Bochum, Universitätsstrasse 150, 44801 Bochum, Germany
| | - Anna S Mitchell
- Department of Experimental Psychology, University of Oxford, The Tinsley Building, Mansfield Road, Oxford OX1 3SR, UK; Equivalent contribution as last authors.
| | - Emmanuel J Barbeau
- Centre de recherche Cerveau et Cognition, UMR5549, Université de Toulouse - CNRS, Toulouse 31000, France; Equivalent contribution as last authors
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Xiong Y, Sui Y, Zhang S, Zhou XJ, Yang S, Fan Y, Zhang Q, Zhu W. Brain microstructural alterations in type 2 diabetes: diffusion kurtosis imaging provides added value to diffusion tensor imaging. Eur Radiol 2018; 29:1997-2008. [DOI: 10.1007/s00330-018-5746-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/03/2018] [Accepted: 09/10/2018] [Indexed: 12/25/2022]
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