scholarly journals IC-P-030: WORSENING FUNCTIONAL CONNECTIVITY WITHIN DEFAULT MODE NETWORK IS ASSOCIATED WITH HIGHER AV-1451 PET UPTAKE IN MEDIAL TEMPORAL LOBE

2019 ◽  
Vol 15 ◽  
pp. P37-P37
Author(s):  
David Scott ◽  
Luc Bracoud ◽  
Kate Adamczuk ◽  
Joyce Suhy ◽  
Keyword(s):  
Functional Connectivity ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Medial Temporal Lobe ◽  
Default Mode

scholarly journals Differential medial temporal lobe and default-mode network functional connectivity and morphometric changes in Alzheimer’s Disease

2017 ◽  
Author(s):  
Kamil A. Grajski ◽  
Steven L. Bressler ◽  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Medial Temporal Lobe ◽  
Resting State Functional Connectivity ◽  
Default Mode

AbstractWe report group level differential detection of medial temporal lobe resting-state functional connectivity disruption and morphometric changes in the transition from cognitively normal to early mild cognitive impairment in an age-, education- and gender-matched 105 subjects Alzheimer’s Disease Neuroimaging Initiative dataset. In mild Alzheimer’s Disease, but not early mild cognitive impairment, characteristic brain atrophy was detected in FreeSurfer estimates of cortical thickness and subcortical and hippocampal subfield volumes. By contrast, functional connectivity analysis detected earlier significant changes. In early mild cognitive impairment these changes involved medial temporal lobe regions of transentorhinal, perirhinal and entorhinal cortices (associated with the earliest stages of neurofibrillary changes in Alzheimer’s Disease), hippocampus, parahippocampal gyrus and temporal pole, and cortical regions comprising or co-activated with the default-mode network, including rostral and medial prefrontal cortex, anterior cingulate cortex, precuneus and inferior temporal cortex. Key findings include: a) focal and bilaterally symmetric spatial organization of affected medial temporal lobe regions; b) mutual hyperconnectivity bilaterally involving ventral medial temporal lobe structures (temporal pole, uncus); and c) dorsal medial temporal lobe hypoconnectivity with anterior and posterior midline default-mode network nodes. These findings position medial temporal lobe resting state functional connectivity as a candidate biomarker of an Alzheimer’s Disease pathophysiological cascade, potentially in advance of clinical biomarkers, and coincident with biomarkers of the earliest stages of Alzheimer’s neuropathology. Our results indicate that medial temporal lobe resting-state functional connectivity should be further investigated as a potential biomarker in the diagnosis of Alzheimer’s Disease.HighlightsFunctional connectivity change seen before structural change in Alzheimer’s DiseaseMedial temporal lobes mutually hyper-connect in mild cognitive impairmentMedial temporal lobe and default mode network decouple in mild cognitive impairmentLoci of functional change in hippocampi are focal with bilaterally symmetric featuresNonmonotonic functional connectivity changes in Alzheimer’s Disease progression

scholarly journals Relationships between default-mode network connectivity, medial temporal lobe structure, and age-related memory deficits

2015 ◽  
Vol 36 (1) ◽  
pp. 265-272 ◽  
Author(s):  
Andrew M. Ward ◽  
Elizabeth C. Mormino ◽  
Willem Huijbers ◽  
Aaron P. Schultz ◽  
Trey Hedden ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Default Mode Network ◽  
Medial Temporal Lobe ◽  
Network Connectivity ◽  
Memory Deficits ◽  
Default Mode ◽  
Age Related

scholarly journals What can narratives tell us about the neural bases of human memory?

2020 ◽  
Author(s):  
Hongmi Lee ◽  
Buddhika Bellana ◽  
janice chen
Keyword(s):  
Temporal Lobe ◽  
Neural Activity ◽  
Default Mode Network ◽  
Medial Temporal Lobe ◽  
Activity Patterns ◽  
Human Memory ◽  
Memory System ◽  
Situation Models ◽  
Neural Synchrony ◽  
Default Mode

Narratives are increasingly used to study naturalistic human memory and its brain mechanisms. Narratives—audiovisual movies, spoken stories, and written stories—consist of multiple inter-related and temporally unfolding events which are rich in semantic and emotional content. These characteristics drive intersubject neural synchrony in the default mode network, where abstract situation models are represented and reinstated. Medial temporal lobe structures interact with the cortical sub-regions of the default mode network to support the encoding and recall of narrative events. Narrative memories are frequently communicated across individuals, resulting in the transmission of experiences and neural activity patterns between people. Recent advances in neuroimaging and naturalistic stimulus analysis provide valuable insights into narrative memory and the human memory system in general.

scholarly journals Default Mode Network in Temporal Lobe epilepsy: interactions with memory performance

2017 ◽  
Author(s):  
Tamires Araujo Zanão ◽  
Tátila Martins Lopes ◽  
Brunno Machado de Campos ◽  
Mateus Henrique Nogueira ◽  
Clarissa Lin Yasuda ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Temporal Lobe Epilepsy ◽  
Left Hemisphere ◽  
Temporal Lobe ◽  
Default Mode Network ◽  
Verbal Memory ◽  
Resting State ◽  
Visual Memory ◽  
Hippocampal Sclerosis ◽  
Default Mode

ABSTRACTObjectiveto investigate abnormal functional connectivity in the resting-state default mode network (DMN) and its relation to memory impairments in patients with temporal lobe epilepsy with and without hippocampal sclerosis (HS)Methodwe enrolled 122 MTLE patients divided into right-HS (n=42), left-HS (n=49), MRI-negative MTLE (n=31) and controls (n=69). All underwent resting-state seed-based connectivity fMRI, with a seed placed at the posterior cingulate cortex, an essential node for the DMN. In addition, patients and 41 controls were tested for verbal and visual memory, estimated intelligence coefficient and delayed recall.ResultsBoth right-HS and MRI-negative group presented the poorest visual memory scores, and right-HS and left-HS had a worse performance in verbal memory compared to controls and MRI-negative groups. As expected, hippocampus was less connected than controls in all groups of patients. Although EEGs indicated that 64.5% of MRI-negative patients were lateralized to the left, this group showed activations similar to the right-HS.ConclusionOur data suggest that there is a disruption of the normal pattern of DMN in MTLE. Patients with left and right-HS presented similar, increased and decreased connectivity in the ipsilateral hemisphere; however, left-HS had abnormal decreased connectivity in the contralateral hemisphere. Per neuropsychological examination, the presence of HS in the left hemisphere had more impact on verbal memory, which was not found when the seizure focus is in the left hemisphere in the absence of HS. The absence of hippocampal atrophy seems to yield a less prominent disruption in both functional connectivity and neuropsychological performance.

scholarly journals The retrosplenial cortex: A memory gateway between the cortical default mode network and the medial temporal lobe

2018 ◽  
Vol 39 (5) ◽  
pp. 2020-2034 ◽  
Author(s):  
Neda Kaboodvand ◽  
Lars Bäckman ◽  
Lars Nyberg ◽  
Alireza Salami
Keyword(s):  
Temporal Lobe ◽  
Default Mode Network ◽  
Medial Temporal Lobe ◽  
Retrosplenial Cortex ◽  
Default Mode
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