scholarly journals Reward enhances memory via age-varying online and offline neural mechanisms across development

2021 ◽  
Author(s):  
Alexandra O Cohen ◽  
Morgan M Glover ◽  
Xinxu Shen ◽  
Camille V Phaneuf ◽  
Kristen N Avallone ◽  
...  
Keyword(s):  
Associative Memory ◽  
Neural Circuits ◽  
Neural Mechanisms ◽  
Age Related ◽  
High Reward ◽  
Memory Representations ◽  
Dopamine Signaling ◽  
Reward Motivation ◽  
The Brain

Reward motivation enhances memory through interactions between mesolimbic, hippocampal, and cortical systems - both during and after encoding. Developmental changes in these distributed neural circuits may lead to age-related differences in reward-motivated memory and the underlying neural mechanisms. Converging evidence from cross-species studies suggests that subcortical dopamine signaling is increased during adolescence, which may lead to stronger memory representations of rewarding, relative to mundane, events and changes in the contributions of underlying subcortical and cortical brain mechanisms across age. Here, we used fMRI to examine how reward motivation influences the "online" encoding and "offline" post-encoding brain mechanisms that support long-term associative memory from childhood to adulthood. We found that reward motivation led to both age-invariant as well as adolescent-specific enhancements in associative memory after 24 hours. Furthermore, reward-related memory benefits were linked to age-varying neural mechanisms. During encoding, interactions between the prefrontal cortex and ventral tegmental area (VTA) were associated with better high-reward memory to a greater degree with increasing age. Pre- to post-encoding changes in functional connectivity between the anterior hippocampus and VTA were also associated with better high-reward memory, but more so at younger ages. Our findings suggest that there may be developmental shifts - from offline subcortical to online cortical processes - in the brain mechanisms supporting reward-motivated memory.

scholarly journals Long-term cyclic aerobic training preserves the brain's health in elderly persons (brief review)

2016 ◽  
Vol 24 (4) ◽  
pp. 152-163
Author(s):  
A S Radchenko ◽  
B B Davydov ◽  
A N Kalinichenko
Keyword(s):  
Aerobic Training ◽  
Brain Perfusion ◽  
Favorable Effect ◽  
Elderly Persons ◽  
Periodical Literature ◽  
Brain Health ◽  
Memory State ◽  
Age Related ◽  
The Brain

It was identified on the base of special periodical literature analyze that cyclic muscular work systematically performed during large part of the person's life (former athlete) provides mainly the favorable effect on the brain. Ventricular-arterial coupling improvement ameliorates brain perfusion, and creates function advantages to brain health in old age. At that, the gray and white matter fading hampered, especially in structures that associated with visual control and human body spatial orientation, motor control and memory state, and age-related attenuation of cognitive functions in comparison with sedentary persons of the same age.

scholarly journals Fronto-striatal Functional Connectivity Supports Reward-Enhanced Memory in Older Adults

2019 ◽  
Author(s):  
Holly J. Bowen ◽  
Jaclyn H. Ford ◽  
Cheryl L. Grady ◽  
Julia Spaniol
Keyword(s):  
Older Adults ◽  
Functional Connectivity ◽  
Healthy Aging ◽  
Inferior Frontal Gyrus ◽  
Neural Mechanisms ◽  
Neural Activation ◽  
Younger Adults ◽  
Age Related ◽  
High Reward ◽  
Neural Underpinnings

AbstractBoth younger and older adults prioritize reward-associated stimuli in memory, but there has been little research on possible age differences in the neural mechanisms mediating this effect. In the current study, we examine neural activation and functional connectivity in healthy younger and older adults to test the hypothesis that older adults would engage prefrontal regions to a greater extent in the service of reward-enhanced memory. While undergoing MRI, target stimuli were presented after high or low-reward cues. The cues indicated the reward value for successfully recognizing the stimulus on a memory test 24-hours later. We replicated prior findings that both older and younger and adults had better memory for high compared to low-reward stimuli. Critically, in older, but not younger adults, this enhanced subsequent memory for high-reward items was supported by greater connectivity between the caudate and bilateral inferior frontal gyrus. The findings add to the growing literature on motivation-cognition interactions in healthy aging, and provide novel evidence of an age-related shift in the neural underpinnings of reward-motivated encoding.

scholarly journals Understanding associative false memories in aging using multivariate analyses

2021 ◽  
Author(s):  
Nancy A. Dennis ◽  
Amy A. Overman ◽  
Catherine M. Carpenter ◽  
Courtney R. Gerver
Keyword(s):  
Associative Memory ◽  
Age Groups ◽  
False Memories ◽  
False Alarms ◽  
Age Difference ◽  
Age Related ◽  
Neural Processes ◽  
Pattern Similarity ◽  
Memory Representations ◽  
Parietal Cortices

Associative memory declines in aging arise, in part, from age-related increases in false memories to recombined lures. Studies have shown that there is a benefit to associative memory if the configural context of associative pairs is maintained from encoding to retrieval. The current study aimed to examine whether this benefit of contextual congruency is reduced in aging, and whether the neural similarity of memory representations between targets and lures underlies age- related increases in false memories. Behaviorally, both age groups benefited from target pairs presented in a visual format that was congruent with how the pair was learned. While no age difference was observed in hits, the typical age-related increase in false alarms was found. Congruent with behavioral results, neither the relationship between target-related patterns of neural activity across memory phases (as measured by ERS) nor the discriminability of target classification as a function of condition at retrieval (as measured by MVPA). However, with regard to false memories, older adults exhibited overall lower pattern similarity for hits and FAs compared to hits and CRs (as measured by RSA). Additionally, Hit-FA RSA correlated with age- related increases in associative FAs across visual, frontal, and parietal cortices. Results suggest that while neural processes supporting associative memory retrieval are dependent on configural congruency between encoding and retrieval, there is no difference as to how congruency affects these processes in aging. Additionally, similarity of target and lure processing may reflect reduced diagnosticity of information processing in aging.

scholarly journals Temporal anticipation based on memory

2016 ◽  
Author(s):  
André M. Cravo ◽  
Gustavo Rohenkohl ◽  
Karin Moreira Santos ◽  
Anna C. Nobre
Keyword(s):  
Associative Memory ◽  
Neural Mechanisms ◽  
Ecological Role ◽  
Dynamic Nature ◽  
Temporal Preparation ◽  
Experimental Approaches ◽  
Neural Markers

AbstractThe fundamental role that our long-term memories play in guiding perception is increasingly recognised, but the functional and neural mechanisms are just beginning to be explored. Though experimental approaches are being developed to investigate the influence of long-term memories on perception, these remain mostly static and neglect their temporal and dynamic nature. Here we show we show that our long-term memories can guide attention proactively and dynamically based on learned temporal associations. Across two experiments we found that detection and discrimination of targets appearing within previously learned contexts are enhanced when the timing of target appearance matches the learned temporal contingency. Neural markers of temporal preparation revealed that the learned temporal associations trigger specific temporal predictions. Our findings emphasize the ecological role that memories play in predicting and preparing perception of anticipated events, calling for revision of the usual conceptualisation of contextual associative memory as a reflective and retroactive function.

scholarly journals Multiple Causes of Dementia as Engineered Senescence

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Mario Dominic Garrett
Keyword(s):  
Antagonistic Pleiotropy ◽  
Misfolded Protein ◽  
Optimal Conditions ◽  
Short Term ◽  
Trade Off ◽  
Age Related ◽  
The Many ◽  
Biology Of Aging ◽  
The Brain

All traumas—cranial, cardiovascular, hormone, viral, bacterial, fungi, parasites, misfolded protein, genetic, behavior, environmental and medication—affect the brain. This paper itemizes studies showing the many different causes of dementia including Alzheimer’s disease. Causes interact with each other, act sequentially by preparing the optimal conditions for its successor, initiate other diseases, allow for other traumas to accumulate and degrade protective features of the brain. Since such age-related cognitive impairment is not exclusively a human attribute there might be support for an evolutionary theory of dementia. Relying on theories of antagonistic pleiotropy and polymorphism, the brain has been designed to sequester trauma. Because of increased longevity, the short-term tactic of sequestering trauma becomes a long-term liability. We are engineered to sequester these insults until a tipping point is reached. Dementia is an evolutionary trade-off for longevity. We cannot cure dementia without understanding the overall biology of aging.

scholarly journals Activation of dopamine receptor 2 (DRD2) prompts transcriptomic and metabolic plasticity in glioblastoma

2018 ◽  
Author(s):  
Seamus P. Caragher ◽  
Jack M. Shireman ◽  
Mei Huang ◽  
Jason Miska ◽  
Shivani Baisiwala ◽  
...  
Keyword(s):  
Autocrine Signaling ◽  
Neuronal Communication ◽  
Metabolic Plasticity ◽  
Mechanistic Investigation ◽  
Elevated Expression ◽  
Dopamine Signaling ◽  
Metabolic Behavior ◽  
Tumor Types ◽  
The Brain

AbstractGlioblastoma (GBM) is one of the most aggressive and lethal tumor types. Evidence continues to accrue indicating that the complex relationship between GBM and the brain microenvironment contributes to this malignant phenotype. However, the interaction between GBM and neurotransmitters, signaling molecules involved in neuronal communication, remains incompletely understood. Here we examined, in both sexes of humans and mice, how the monoamine dopamine influences GBM cells. We demonstrate that GBM cells express DRD2, with elevated expression in the glioma-initiating cell (GIC) population. Stimulation of DRD2 caused neuron-like depolarization exclusively in GICs. In addition, long-term activation of DRD2 heightened the sphere-forming capacity of GBM cells as well as tumor engraftment efficiency. Mechanistic investigation revealed that DRD2 signaling activates the hypoxia response and functionally alters metabolism. Finally, we found that GBM cells synthesize and secrete dopamine themselves, suggesting a potential autocrine mechanism. These results identify dopamine signaling as a potential therapeutic target in GBM and further highlight neurotransmitters as a key feature of the pro-tumor microenvironment.Significance StatementThis work offers critical insight into the role of the neurotransmitter dopamine in the progression of GBM. We show that dopamine induces specific changes in the state of tumor cells, augmenting their growth and shifting them to a more stem-cell like state. Further, we show that dopamine can alter the metabolic behavior of GBM cells, increasing glycolysis. Finally, we show that GBM cells, including tumor samples from patients, can synthesize and secrete dopamine, suggesting an autocrine signaling process underlying these results. These results describe a novel connection between neurotransmitters and brain cancer, further highlighting the critical influence of the brain milieu on GBM.

scholarly journals Understanding the Potential Role of Sirtuin 2 on Aging: Consequences of SIRT2.3 Overexpression in Senescence

2021 ◽  
Vol 22 (6) ◽  
pp. 3107
Author(s):  
Noemi Sola-Sevilla ◽  
Ana Ricobaraza ◽  
Ruben Hernandez-Alcoceba ◽  
Maria S. Aymerich ◽  
Rosa M. Tordera ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Potential Role ◽  
Adeno Associated Virus ◽  
Age Related ◽  
Age Dependent ◽  
Molecular Effects ◽  
Samp8 Mice ◽  
The Brain

Sirtuin 2 (SIRT2) has been associated to aging and age-related pathologies. Specifically, an age-dependent accumulation of isoform 3 of SIRT2 in the CNS has been demonstrated; however, no study has addressed the behavioral or molecular consequences that this could have on aging. In the present study, we have designed an adeno-associated virus vector (AAV-CAG-Sirt2.3-eGFP) for the overexpression of SIRT2.3 in the hippocampus of 2 month-old SAMR1 and SAMP8 mice. Our results show that the specific overexpression of this isoform does not induce significant behavioral or molecular effects at short or long term in the control strain. Only a tendency towards a worsening in the performance in acquisition phase of the Morris Water Maze was found in SAMP8 mice, together with a significant increase in the pro-inflammatory cytokine Il-1β. These results suggest that the age-related increase of SIRT2.3 found in the brain is not responsible for induction or prevention of senescence. Nevertheless, in combination with other risk factors, it could contribute to the progression of age-related processes. Understanding the specific role of SIRT2 on aging and the underlying molecular mechanisms is essential to design new and more successful therapies for the treatment of age-related diseases.

scholarly journals Self-organized reactivation maintains and reinforces memories despite synaptic turnover

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Michael Jan Fauth ◽  
Mark CW van Rossum
Keyword(s):  
Computational Model ◽  
Associative Memory ◽  
Structural Plasticity ◽  
Pattern Completion ◽  
Self Organized ◽  
Rest Periods ◽  
Memory Representations ◽  
Cortical Synapses ◽  
Variable Substrate

Long-term memories are believed to be stored in the synapses of cortical neuronal networks. However, recent experiments report continuous creation and removal of cortical synapses, which raises the question how memories can survive on such a variable substrate. Here, we study the formation and retention of associative memory in a computational model based on Hebbian cell assemblies in the presence of both synaptic and structural plasticity. During rest periods, such as may occur during sleep, the assemblies reactivate spontaneously, reinforcing memories against ongoing synapse removal and replacement. Brief daily reactivations during rest-periods suffice to not only maintain the assemblies, but even strengthen them, and improve pattern completion, consistent with offline memory gains observed experimentally. While the connectivity inside memory representations is strengthened during rest phases, connections in the rest of the network decay and vanish thus reconciling apparently conflicting hypotheses of the influence of sleep on cortical connectivity.

scholarly journals Electro-optical mechanically flexible coaxial microprobes for minimally invasive interfacing with intrinsic neural circuits

2020 ◽  
Author(s):  
Spencer Ward ◽  
Conor Riley ◽  
Erin M. Carey ◽  
Jenny Nguyen ◽  
Sadik Esener ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Optical Materials ◽  
Neural Circuits ◽  
Inflammatory Responses ◽  
Electrical Measurement ◽  
Optogenetic Stimulation ◽  
Mechanical Compliance ◽  
New Generation ◽  
The Brain

Central to advancing our understanding of neural circuits is the development of minimally invasive, multi-modal interfaces capable of simultaneously recording and modulating neural activity. Recent devices have focused on matching the mechanical compliance of tissue to reduce inflammatory responses1,2. However, reductions in the size of multi-modal interfaces are needed to further improve biocompatibility and long-term recording capabilities1. Here we demonstrate a multi-modal coaxial microprobe design with a minimally invasive footprint (8-12 μm diameter over millimeter lengths) that enables efficient electrical and optical interrogation of neural networks. In the brain, the probes allowed robust electrical measurement and optogenetic stimulation. Scalable fabrication strategies can be used with various electrical and optical materials, making the probes highly customizable to experimental requirements, including length, diameter, and mechanical properties. Given their negligible inflammatory response, these probes promise to enable a new generation of readily tunable multi-modal devices for minimally invasive interfacing with neural circuits.

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