scholarly journals Hibernation does not affect memory retention in bats

2010 ◽  
Vol 7 (1) ◽  
pp. 153-155 ◽  
Author(s):  
Ireneusz Ruczynski ◽  
Björn M. Siemers
Keyword(s):  
Brain Function ◽  
Memory Impairment ◽  
Memory Loss ◽  
High Mobility ◽  
Ground Squirrels ◽  
Long Term Memory ◽  
Memory Retention ◽  
High Level ◽  
First Time

Long-term memory can be critically important for animals in a variety of contexts, and yet the extreme reduction in body temperature in hibernating animals alters neurochemistry and may therefore impair brain function. Behavioural studies on memory impairment associated with hibernation have been almost exclusively conducted on ground squirrels (Rodentia) and provide conflicting results, including clear evidence for memory loss. Here, we for the first time tested memory retention after hibernation for a vertebrate outside rodents—bats (Chiroptera). In the light of the high mobility, ecology and long life of bats, we hypothesized that maintenance of consolidated memory through hibernation is under strong natural selection. We trained bats to find food in one out of three maze arms. After training, the pre-hibernation performance of all individuals was at 100 per cent correct decisions. After this pre-test, one group of bats was kept, with two interruptions, at 7°C for two months, while the other group was kept under conditions that prevented them from going into hibernation. The hibernated bats performed at the same high level as before hibernation and as the non-hibernated controls. Our data suggest that bats benefit from an as yet unknown neuroprotective mechanism to prevent memory loss in the cold brain.

Assessment of Memory Impairment in Early Diagnosis of Alzheimer’s Disease

2019 ◽  
Vol 16 (11) ◽  
pp. 975-985
Author(s):  
Martin Vyhnálek ◽  
Hana Marková ◽  
Jan Laczó ◽  
Rossana De Beni ◽  
Santo Di Nuovo
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Memory Impairment ◽  
Recent Progress ◽  
Memory Loss ◽  
Long Term Memory ◽  
Cognitive Changes ◽  
Memory Assessment ◽  
Memory Binding

Memory impairment has been considered as one of the earliest clinical hallmarks of Alzheimer’s disease. This paper summarizes recent progress in the assessment of memory impairment in predementia stages. New promising approaches of memory assessment include evaluation of longitudinal cognitive changes, assessment of long-term memory loss, evaluation of subjective cognitive concerns and testing of other memory modalities, such as spatial memory. In addition, we describe new challenging memory tests based on memory binding paradigms that have been recently developed and are currently being validated.

scholarly journals EXPRESS: Two Variations and One Similarity in Memory Functions Deployed by Mice and Humans to Support Foraging

2021 ◽  
pp. 174702182110105
Author(s):  
Spencer Talbot ◽  
Todor Gerdjikov ◽  
Carlo De Lillo
Keyword(s):  
Working Memory ◽  
Brain Function ◽  
Visual Cues ◽  
Brain Structures ◽  
Human Cognition ◽  
Foraging Efficiency ◽  
Long Term Memory ◽  
Memory Functions ◽  
Term Memory

Assessing variations in cognitive function between humans and animals is vital for understanding the idiosyncrasies of human cognition and for refining animal models of human brain function and disease. We determined memory functions deployed by mice and humans to support foraging with a search task acting as a test battery. Mice searched for food from the top of poles within an open-arena. Poles were divided into groups based on visual cues and baited according to different schedules. White and black poles were baited in alternate trials. Striped poles were never baited. The requirement of the task was to find all baits in each trial. Mice’s foraging efficiency, defined as the number of poles visited before all baits were retrieved, improved with practice. Mice learnt to avoid visiting un-baited poles across trials (Long-term memory) and revisits to poles within each trial (Working memory). Humans tested with a virtual-reality version of the task outperformed mice in foraging efficiency, working memory and exploitation of the temporal pattern of rewards across trials. Moreover, humans, but not mice, reduced the number of possible movement sequences used to search the set of poles. For these measures interspecies differences were maintained throughout three weeks of testing. By contrast, long-term-memory for never-rewarded poles was similar in mice and humans after the first week of testing. These results indicate that human cognitive functions relying upon archaic brain structures may be adequately modelled in mice. Conversely, modelling in mice fluid skills likely to have developed specifically in primates, requires caution.

The Relationship Between Brain Fog and Medication Adherence for Individuals With Hypothyroidism

2021 ◽  
pp. 105477382110381
Author(s):  
Kelly Haskard-Zolnierek ◽  
Courtney Wilson ◽  
Julia Pruin ◽  
Rebecca Deason ◽  
Krista Howard
Keyword(s):  
Memory Impairment ◽  
Hormone Replacement ◽  
Long Term Memory ◽  
Adherence Level ◽  
Thyroid Hormone Replacement ◽  
Memory Impairments ◽  
Cognitive Failures ◽  
Short And Long Term ◽  
The Relationship

Individuals with hypothyroidism suffer from symptoms including impairments to cognition (i.e., “brain fog”). Medication can help reduce symptoms of hypothyroidism; however, brain fog may hinder adherence. The aim of this study was to determine if memory impairment and cognitive failures are related to treatment nonadherence in 441 individuals with hypothyroidism. Participants with a diagnosis of hypothyroidism and currently prescribed a thyroid hormone replacement medication were placed in two groups according to adherence level and compared on validated scales assessing impairments to memory and cognition. Results indicated a significant association between treatment nonadherence and self-reported brain fog, represented by greater cognitive and memory impairments. Nonadherent individuals indicated impairments with prospective, retrospective, and short- and long-term memory; and more cognitive failures, compared to adherent individuals. Findings suggest the importance of interventions to enhance adherence for individuals with brain fog, such as encouraging the use of reminders.

scholarly journals COMPLEXITY-BASED ANALYSIS OF THE ALTERATIONS IN THE STRUCTURE OF CORONAVIRUSES

Fractals ◽  
2021 ◽  
Vol 29 (02) ◽  
pp. 2150123
Author(s):  
HAMIDREZA NAMAZI ◽  
ALI SELAMAT ◽  
ONDREJ KREJCAR
Keyword(s):  
Hurst Exponent ◽  
Complex Structure ◽  
Approximate Entropy ◽  
Sample Entropy ◽  
Long Term Memory ◽  
Complex Structures ◽  
Term Memory ◽  
The World ◽  
First Time

The coronavirus has influenced the lives of many people since its identification in 1960. In general, there are seven types of coronavirus. Although some types of this virus, including 229E, NL63, OC43, and HKU1, cause mild to moderate illness, SARS-CoV, MERS-CoV, and SARS-CoV-2 have shown to have severer effects on the human body. Specifically, the recent known type of coronavirus, SARS-CoV-2, has affected the lives of many people around the world since late 2019 with the disease named COVID-19. In this paper, for the first time, we investigated the variations among the complex structures of coronaviruses. We employed the fractal dimension, approximate entropy, and sample entropy as the measures of complexity. Based on the obtained results, SARS-CoV-2 has a significantly different complex structure than SARS-CoV and MERS-CoV. To study the high mutation rate of SARS-CoV-2, we also analyzed the long-term memory of genome walks for different coronaviruses using the Hurst exponent. The results demonstrated that the SARS-CoV-2 shows the lowest memory in its genome walk, explaining the errors in copying the sequences along the genome that results in the virus mutation.

The effects of continuous versus partial reinforcement schedules on associative learning, memory and extinction in Lymnaea stagnalis

2002 ◽  
Vol 205 (8) ◽  
pp. 1171-1178 ◽  
Author(s):  
Susan Sangha ◽  
Chloe McComb ◽  
Andi Scheibenstock ◽  
Christine Johannes ◽  
Ken Lukowiak
Keyword(s):  
Associative Learning ◽  
Operant Conditioning ◽  
Lymnaea Stagnalis ◽  
Partial Reinforcement ◽  
Long Term Memory ◽  
Memory Retention ◽  
Reinforcement Schedules ◽  
Conditioning Procedure ◽  
Term Memory

SUMMARY A continuous schedule of reinforcement (CR) in an operant conditioning procedure results in the acquisition of associative learning and the formation of long-term memory. A 50 % partial reinforcement (PR) schedule does not result in learning. The sequence of PR—CR training has different and significant effects on memory retention and resistance to extinction. A CR/PR schedule results in a longer-lasting memory than a PR/CR schedule. Moreover,the memory produced by the CR/PR schedule is resistant to extinction training. In contrast, extinction occurs following the PR/CR schedule.

scholarly journals Adverse effects of GHB-induced coma on long-term memory and related brain function

2018 ◽  
Vol 190 ◽  
pp. 29-36 ◽  
Author(s):  
Filipa Raposo Pereira ◽  
Minni T.B. McMaster ◽  
Nikki Polderman ◽  
Yvon D.A.T. de Vries ◽  
Wim van den Brink ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Brain Function ◽  
Long Term Memory ◽  
Term Memory

scholarly journals Higher iridescent-to-pigment optical effect in flowers facilitates learning, memory and generalization in foraging bumblebees

2017 ◽  
Vol 284 (1865) ◽  
pp. 20171097 ◽  
Author(s):  
Géraud de Premorel ◽  
Martin Giurfa ◽  
Christine Andraud ◽  
Doris Gomez
Keyword(s):  
Bombus Terrestris ◽  
Optical Measurements ◽  
Long Term Memory ◽  
Memory Retention ◽  
Optical Effect ◽  
Plant Communication ◽  
Bona Fide ◽  
Angle Of View ◽  
Artificial Flowers

Iridescence—change of colour with changes in the angle of view or of illumination—is widespread in the living world, but its functions remain poorly understood. The presence of iridescence has been suggested in flowers where diffraction gratings generate iridescent colours. Such colours have been suggested to serve plant–pollinator communication. Here we tested whether a higher iridescence relative to corolla pigmentation would facilitate discrimination, learning and retention of iridescent visual targets. We conditioned bumblebees ( Bombus terrestris ) to discriminate iridescent from non-iridescent artificial flowers and we varied iridescence detectability by varying target iridescent relative to pigment optical effect. We show that bees rewarded on targets with higher iridescent relative to pigment effect required fewer choices to complete learning, showed faster generalization to novel targets exhibiting the same iridescence-to-pigment level and had better long-term memory retention. Along with optical measurements, behavioural results thus demonstrate that bees can learn iridescence-related cues as bona fide signals for flower reward. They also suggest that floral advertising may be shaped by competition between iridescence and corolla pigmentation, a fact that has important evolutionary implications for pollinators. Optical measurements narrow down the type of cues that bees may have used for learning. Beyond pollinator–plant communication, our experiments help understanding how receivers influence the evolution of iridescence signals generated by gratings.

Separate chemical inhibitors of long-term and short-term memory: contrasting effects of cycloheximide, ouabain and ethacrynic acid on various learning tasks in chickens

1977 ◽  
Vol 196 (1123) ◽  
pp. 171-195 ◽  
Keyword(s):  
Visual Discrimination ◽  
Short Term Memory ◽  
Ethacrynic Acid ◽  
Fixed Number ◽  
Long Term Memory ◽  
Training Procedure ◽  
Memory Retention ◽  
Short Term ◽  
Term Memory

Cycloheximide injected into the brains of chickens 10 min before training does not effect their learning of a visual discrimination task, or memory of that task for at least 1 h after training. When tested 24 h later no memory of the training procedure is detectable. In contrast, ouabain injected 10 min before training prevents the expression of learning during training. The block lasts for up to 1 h, but from that time on memory begins to appear. Ouabain does not affect performance when injected just before testing for memory retention 24 h after training. It therefore affects neither the readout of long-term memory nor motivation nor perceptual abilities necessary for performance of the learning task. In birds treated with ouabain, after training on an operant task for heat reward by a procedure requiring a fixed number of reinforcements, memory is absent 20 min later but is well established at 24 h. Cycloheximide blocks long-term memory of this task. Like ouabain, ethacrynic acid, injected into the brain of chickens 10 min before training prevents the expression of learning of visual discrimination. Ethacrynic acid hastens the decline of memory after one-trial passive avoidance learning. It also blocks observational learning. We conclude that ouabain and ethacrynic acid block access to short-term memory, whereas cycloheximide interferes with the registration of long-term memory. Comparing the pharmacology of ethacrynic acid and ouabain their common known actions are on the Na/K fluxes across cell membranes. We suggest that long lasting changes in distribution of these ions in recently active nerve cells may be at the basis of access to memory during and shortly after learning.

scholarly journals Robust Recall and Long-Term Memory T-Cell Responses Induced by Prime-Boost Regimens with Heterologous Live Viral Vectors Expressing Human Immunodeficiency Virus Type 1 Gag and Env Proteins

2002 ◽  
Vol 76 (15) ◽  
pp. 7506-7517 ◽  
Author(s):  
Karl Haglund ◽  
Ingrid Leiner ◽  
Kristen Kerksiek ◽  
Linda Buonocore ◽  
Eric Pamer ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Vaccinia Virus ◽  
Human Immunodeficiency Virus Type ◽  
Long Term Memory ◽  
Term Memory ◽  
Immunodeficiency Virus ◽  
High Level ◽  
Hiv 1

ABSTRACT We investigated long-term memory and recall cellular immune responses to human immunodeficiency virus type 1 (HIV-1) Env and Gag proteins elicited by recombinant vesicular stomatitis viruses (VSVs) expressing Env and Gag. More than 7 months after a single vaccination with VSV-Env, ∼6% of CD8+ splenocytes stained with major histocompatibility complex class I tetramers containing the Env p18-I10 immunodominant peptide and showed a memory phenotype (CD44Hi). The level of tetramer-positive cells in memory was about 14% of the peak primary response. Recall responses elicited in these mice 5 days after boosting with a heterologous recombinant vaccinia virus expressing HIV-1 Env showed that 40 to 45% of CD8+ splenocytes were tetramer positive and activated (CD62LLo), and these cells produced gamma interferon after stimulation with Env peptide, indicating that they were functional. Five months after the boost, the long-term memory cell population (tetramer positive, CD44Hi) constituted 30% of the CD8+ splenocytes. Recall responses to HIV-1 Gag were examined in mice primed with VSV recombinants expressing HIV-1 Gag protein and boosted with a vaccinia virus recombinant expressing Gag. Using this protocol, we found that ∼40% of CD8+ splenocytes were activated (CD62LLo) and specific for a Gag immunodominant peptide (tetramer positive). The high-level Gag recall response elicited by the vaccinia virus-Gag was greater than that obtained by boosting with a VSV-Gag vector with a different VSV glycoprotein. The corresponding levels of CD44Hi memory cells were also higher long after boosting with vaccinia virus-Gag than after boosting with a glycoprotein exchange VSV-Gag. Our results show that VSV vectors elicit high-level memory CTL responses and that these can be amplified as much as six- to sevenfold using a heterologous boosting vector.

Long-term memory impairment in patients with focal epilepsy

Epilepsia ◽  
2007 ◽  
Vol 48 ◽  
pp. 26-29 ◽  
Author(s):  
Christian Hoppe ◽  
Christian E. Elger ◽  
Christoph Helmstaedter
Keyword(s):  
Memory Impairment ◽  
Focal Epilepsy ◽  
Long Term Memory ◽  
Term Memory
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