Proceedings #5: Optogenetically-initiated Low Frequency Dorsal Hippocampal Activity Enhances rsfMRI Functional Connectivity and Long-term Visual Memory Performance

2019 ◽  
Vol 12 (2) ◽  
pp. e62-e63
Author(s):  
Ed X. Wu ◽  
Alex T.L. Leong ◽  
Russell W. Chan ◽  
Eddie C. Wong
2009 ◽  
Vol 21 (2) ◽  
pp. 67-74 ◽  
Author(s):  
Stefan Begré ◽  
Claus Kiefer ◽  
Roland von Känel ◽  
Angela Frommer ◽  
Andrea Federspiel

Objective:Studies exploring relation of visual memory to white matter are extensively lacking. The Rey Visual Design Learning Test (RVDLT) is an elementary motion, colour and word independent visual memory test. It avoids a significant contribution from as many additional higher order visual brain functions as possible to visual performance, such as three-dimensional, colour, motion or word-dependent brain operations. Based on previous results, we hypothesised that test performance would be related with white matter of dorsal hippocampal commissure, corpus callosum, posterior cingulate, superior longitudinal fascicle and internal capsule.Methods:In 14 healthy subjects, we measured intervoxel coherence (IC) by diffusion tensor imaging as an indication of connectivity and visual memory performance measured by the RVDLT. IC considers the orientation of the adjacent voxels and has a better signal-to-noise ratio than the commonly used fractional anisotropy index.Results:Using voxelwise linear regression analyses of the IC values, we found a significant and direct relationship between 11 clusters and visual memory test performance. The fact that memory performance correlated with white matter structure in left and right dorsal hippocampal commissure, left and right posterior cingulate, right callosal splenium, left and right superior longitudinal fascicle, right medial orbitofrontal region, left anterior cingulate, and left and right anterior limb of internal capsule emphasises our hypothesis.Conclusion:Our observations in healthy subjects suggest that individual differences in brain function related to the performance of a task of higher cognitive demands might partially be associated with structural variation of white matter regions.


2016 ◽  
Vol 21 (4) ◽  
pp. 267-283 ◽  
Author(s):  
Timo Skodzik ◽  
Heinz Holling ◽  
Anya Pedersen

Objective: Memory problems are a frequently reported symptom in adult ADHD, and it is well-documented that adults with ADHD perform poorly on long-term memory tests. However, the cause of this effect is still controversial. The present meta-analysis examined underlying mechanisms that may lead to long-term memory impairments in adult ADHD. Method: We performed separate meta-analyses of measures of memory acquisition and long-term memory using both verbal and visual memory tests. In addition, the influence of potential moderator variables was examined. Results: Adults with ADHD performed significantly worse than controls on verbal but not on visual long-term memory and memory acquisition subtests. The long-term memory deficit was strongly statistically related to the memory acquisition deficit. In contrast, no retrieval problems were observable. Conclusion: Our results suggest that memory deficits in adult ADHD reflect a learning deficit induced at the stage of encoding. Implications for clinical and research settings are presented.


2017 ◽  
Author(s):  
Blanca Marin Bosch ◽  
Aurélien Bringard ◽  
Maria Grazia Logrieco ◽  
Estelle Lauer ◽  
Nathalie Imobersteg ◽  
...  

AbstractRegular physical exercise enhances memory functions and neurogenesis in the hippocampus, an effect partially mediated by BDNF (Brain Derived Neurotrophic Factor). Acute exercise promotes the release of endocannabinoids (especially anandamide, AEA), which enhance BDNF release and improve hippocampal plasticity in rodents. How acute exercise affects BDNF and AEA levels and influences memory performance in humans remains to date unknown. Here we combined blood biomarkers, behavioral and fMRI measurements to assess the impact of acute physical exercise on associative memory and underlying neurophysiological mechanisms. For each participant, memory was tested after three conditions: rest, moderate or high exercise intensity. A long-term memory retest took place 3 months later. At both test and retest, memory performance increased after moderate but not high intensity exercise or rest. We also show that memory benefited from exercise-related increases in both AEA and BNDF levels: AEA boosted hippocampal activity during memory recall, while BDNF enhanced hippocampal memory representations and long-term performance.


2021 ◽  
Author(s):  
Tribikram Thapa ◽  
Joshua Hendrikse ◽  
Sarah Thompson ◽  
Chao Suo ◽  
Mana Biabani ◽  
...  

Continuous theta burst stimulation (cTBS) is thought to reduce cortical excitability and modulate functional connectivity, possibly by altering cortical inhibition at the site of stimulation. However, most evidence comes from the motor cortex and it remains unclear whether similar effects occur following stimulation over other brain regions. We assessed whether cTBS over left dorsolateral prefrontal cortex altered gamma aminobutyric acid (GABA) concentration, functional connectivity and brain dynamics at rest, and brain activation and memory performance during a working memory task. Seventeen healthy individuals participated in a randomised, sham-controlled, cross-over experiment. Before and after either real or sham cTBS, magnetic resonance spectroscopy was obtained at rest to measure GABA concentrations, whereas functional magnetic resonance imaging (fMRI) was recorded at rest and during an n-back working memory task to measure functional connectivity, brain dynamics (low-frequency fluctuations), and task-related patterns of brain activity. We could not find evidence for changes in GABA concentration (P=0.66, Bayes factor [BF10]=0.07), resting-state functional connectivity (P(FWE)>0.05), resting-state low-frequency fluctuations (P=0.88, BF10=0.04), blood-oxygen level dependent activity during the n-back task (P(FWE) >0.05), or working memory performance (P=0.13, BF10=0.05) following real or sham cTBS. Our findings add to a growing body of literature suggesting the effects of cTBS are highly variable between individuals and question the notion that cTBS is a universal 'inhibitory' paradigm.


2020 ◽  
Vol 48 (7) ◽  
pp. 1196-1213
Author(s):  
Alicia Forsberg ◽  
Wendy Johnson ◽  
Robert H. Logie

Abstract The decline of working memory (WM) is a common feature of general cognitive decline, and visual and verbal WM capacity appear to decline at different rates with age. Visual material may be remembered via verbal codes or visual traces, or both. Souza and Skóra, Cognition, 166, 277–297 (2017) found that labeling boosted memory in younger adults by activating categorical visual long-term memory (LTM) knowledge. Here, we replicated this and tested whether it held in healthy older adults. We compared performance in silence, under instructed overt labeling (participants were asked to say color names out loud), and articulatory suppression (repeating irrelevant syllables to prevent labeling) in the delayed estimation paradigm. Overt labeling improved memory performance in both age groups. However, comparing the effect of overt labeling and suppression on the number of coarse, categorical representations in the two age groups suggested that older adults used verbal labels subvocally more than younger adults, when performing the task in silence. Older adults also appeared to benefit from labels differently than younger adults. In younger adults labeling appeared to improve visual, continuous memory, suggesting that labels activated visual LTM representations. However, for older adults, labels did not appear to enhance visual, continuous representations, but instead boosted memory via additional verbal (categorical) memory traces. These results challenged the assumption that visual memory paradigms measure the same cognitive ability in younger and older adults, and highlighted the importance of controlling differences in age-related strategic preferences in visual memory tasks.


2013 ◽  
Vol 19 (13) ◽  
pp. 1765-1772 ◽  
Author(s):  
Maureen Lacy ◽  
Meagan Hauser ◽  
Neil Pliskin ◽  
Stephanie Assuras ◽  
Mildred O Valentine ◽  
...  

Background: Multiple sclerosis (MS) is a progressive disease of the central nervous system that affects cognition. Short-term treatment with interferon-beta-1b (IFN-b-1b) has been shown to have beneficial effects on cognition. Objective: The objective of this paper is to evaluate the effects of IFN-b-1b on cognitive functioning in patients with MS over the course of 16 years. Methods: Sixteen subjects with relapsing–remitting MS participated in the study. Nine of these subjects received IFN-b-1b, while seven received placebo treatment in the pivotal MS trial. After five years, all subjects were switched to IFN-b-1b treatment. At two and four years into the study, all subjects underwent a brief neuropsychological test battery, magnetic resonance imaging (MRI), and neurologic ratings; measures were repeated at 16 years. Results: Across the total cohort, cognitive functioning remained relatively stable over the course of 16 years. The placebo/IFN-b-b group exhibited increased visual memory performance relative to the IFN-b-1b treatment group, but had a greater decline in verbal memory. Initial MRI lesion load demonstrated a significant, negative correlation with overall cognitive performance at 16 years ( p = 0.00). Conclusion: We conclude that IFN-b-1b has beneficial effects on long-term cognition outcomes in MS.


2017 ◽  
Vol 18 (3) ◽  
pp. 655 ◽  
Author(s):  
Nesli Avgan ◽  
Heidi Sutherland ◽  
Lauren Spriggens ◽  
Chieh Yu ◽  
Omar Ibrahim ◽  
...  

2018 ◽  
Author(s):  
M.J. Spriggs ◽  
C.S. Thompson ◽  
D Moreau ◽  
N.A. McNair ◽  
C.C. Wu ◽  
...  

BackgroundLong-Term Potentiation (LTP) is recognised as a core neuronal process underlying long-term memory. However, a direct relationship between LTP and human memory performance is yet to be demonstrated. The first aim of the current study was thus to assess the relationship between LTP and human long-term memory performance. With this also comes an opportunity to explore factors thought to mediate the relationship between LTP and long-term memory, and to gain additional insight into variations in memory function and memory decline. The second aim of the current study was to explore the relationship between LTP and memory in groups differing with respect to BDNF Val66Met; a single nucleotide polymorphism implicated in memory function.Methods28 participants (15 female) were split into three genotype groups (Val/Val, Val/Met, Met/Met) and were presented with both an EEG paradigm for inducing LTP-like enhancements of the visually-evoked response, and a test of visual memory.ResultsThe magnitude of LTP 40 minutes after induction was predictive of long-term memory performance. Additionally, the BDNF Met allele was associated with both reduced LTP and reduced memory performance.ConclusionsThe current study not only presents the first evidence for a relationship between sensory LTP and human memory performance, but also demonstrates how targeting this relationship can provide insight into factors implicated in variation in human memory performance. It is anticipated that this will be of utility to future clinical studies of disrupted memory function.


Hippocampus ◽  
2010 ◽  
Vol 20 (12) ◽  
pp. 1366-1375 ◽  
Author(s):  
Nicola J. Broadbent ◽  
Larry R. Squire ◽  
Robert E. Clark

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