scholarly journals Combination of successor representation-based appetitive learning and individual representation-based aversive learning is a good strategy and can be implemented in the cortico-basal ganglia circuits

2021 ◽  
Author(s):  
Kenji Morita ◽  
Kanji Shimomura ◽  
Yasuo Kawaguchi
Keyword(s):  
Basal Ganglia ◽  
Learning Strategy ◽  
Prediction Errors ◽  
Neural Pathways ◽  
Aversive Learning ◽  
Effective Learning ◽  
Learning Rates ◽  
Combined Use ◽  
Negative Feedbacks ◽  
The Brain

While positive reward prediction errors (RPEs) and negative RPEs have equal impacts in the standard reinforcement learning, the brain appears to have distinct neural pathways for learning mainly from either positive or negative feedbacks, such as the direct and indirect pathways of the basal ganglia (BG). Given that distinct pathways may receive inputs unevenly from different neural populations and/or regions, how states or actions are represented can differ between the pathways. We explored whether combined use of different representations, coupled with different learning rates from positive and negative RPEs, has computational benefits. We considered an agent equipped with two learning systems, each of which adopted individual representation (IR) or successor representation (SR) of states. With varying the combination of IR or SR and also the learning rates from positive and negative RPEs in each system, we examined how the agent performed in a certain dynamic reward environment. We found that combination of SR-based system learning mainly from positive RPEs and IR-based system learning mainly from negative RPEs outperformed the other combinations, including IR-only or SR-only cases and the cases where the two systems had the same ratios of positive- and negative-RPE-based learning rates. In the best combination case, both systems show activities of comparable magnitudes with opposite signs, consistent with suggested profiles of BG pathways. These results suggest that particularly combining different representations with appetitive and aversive learning could be an effective learning strategy in a certain dynamic reward environment, and it might actually be implemented in the cortico-BG circuits.

Is testing a more effective learning strategy than note-taking?

2017 ◽  
Vol 23 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Ralf Rummer ◽  
Judith Schweppe ◽  
Kathleen Gerst ◽  
Simon Wagner
Keyword(s):  
Learning Strategy ◽  
Note Taking ◽  
Effective Learning

EFEKTIVITAS STRATEGI CLOZE STORY MAPPING TERHADAP KEMAMPUAN MEMBACA PEMAHAMAN PADA SISWA KELAS V DI SD 2 PADOKAN KASIHAN BANTUL

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Danuri Danuri ◽  
Dwendha Lahitani
Keyword(s):  
Data Analysis ◽  
Learning Strategy ◽  
T Test ◽  
Effective Learning ◽  
Average Value ◽  
Story Mapping ◽  
Analysis Technique ◽  
Significant Difference ◽  
Quasi Experimental ◽  
Class Average

This study aims to determine the effectiveness of CSM strategies on comprehension reading skills in classes V Padokan 2 Elementary School. The research method used is a quasi-experimental method. In this study the subjects of the study were VA class students as the control class and V C as the experimental class with 28 VA and VC class students. Quantitative data analysis technique used is the calculation of independent sample t-test. Based on data analysis and discussion, researchers can conclude that CSM strategies are more effective than conventional methods of reading comprehension learning. The results of this study indicate that there is a significant difference between the experimental class and the control class as evidenced by the results of the independent sample t-test obtained by the value of Asymp. Sig (2-Tailed) 0.014 <0.05. CSM strategy is an effective learning strategy seen from the average value of the experimental class posstest which is 81.61 higher than the control class average value of 72.96.

Current Strategies and Novel Drug Approaches for Alzheimer Disease

2020 ◽  
Vol 19 (9) ◽  
pp. 676-690 ◽  
Author(s):  
Roma Ghai ◽  
Kandasamy Nagarajan ◽  
Meenakshi Arora ◽  
Parul Grover ◽  
Nazakat Ali ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cholinergic Neurons ◽  
Amyloid Plaque ◽  
Neural Pathways ◽  
Current Trends ◽  
Personality Changes ◽  
Traditional Therapies ◽  
Novel Drug ◽  
The Brain

Alzheimer’s Disease (AD) is a chronic, devastating dysfunction of neurons in the brain leading to dementia. It mainly arises due to neuronal injury in the cerebral cortex and hippocampus area of the brain and is clinically manifested as a progressive mental failure, disordered cognitive functions, personality changes, reduced verbal fluency and impairment of speech. The pathology behind AD is the formation of intraneuronal fibrillary tangles, deposition of amyloid plaque and decline in choline acetyltransferase and loss of cholinergic neurons. Tragically, the disease cannot be cured, but its progression can be halted. Various cholinesterase inhibitors available in the market like Tacrine, Donepezil, Galantamine, Rivastigmine, etc. are being used to manage the symptoms of Alzheimer’s disease. The paper’s objective is to throw light not only on the cellular/genetic basis of the disease, but also on the current trends and various strategies of treatment including the use of phytopharmaceuticals and nutraceuticals. Enormous literature survey was conducted and published articles of PubMed, Scifinder, Google Scholar, Clinical Trials.org and Alzheimer Association reports were studied intensively to consolidate the information on the strategies available to combat Alzheimer’s disease. Currently, several strategies are being investigated for the treatment of Alzheimer’s disease. Immunotherapies targeting amyloid-beta plaques, tau protein and neural pathways are undergoing clinical trials. Moreover, antisense oligonucleotide methodologies are being approached as therapies for its management. Phytopharmaceuticals and nutraceuticals are also gaining attention in overcoming the symptoms related to AD. The present review article concludes that novel and traditional therapies simultaneously promise future hope for AD treatment.

scholarly journals Basal Ganglia Herniation into the Fourth Ventricle

1997 ◽  
Vol 24 (1) ◽  
pp. 62-63 ◽  
Author(s):  
Mensura Altumbabic ◽  
Marc R. Del Bigio ◽  
Scott Sutherland
Keyword(s):  
Basal Ganglia ◽  
Intracerebral Hemorrhage ◽  
Fourth Ventricle ◽  
Transtentorial Herniation ◽  
Intracerebral Bleeding ◽  
Rare Phenomenon ◽  
The Brain

ABSTRACT:Background:Transtentorial herniation of large cerebral fragments is a rare phenomenon.Method:Case StudyResults:Examination of the brain of a 35-year-old male showed massive intracerebral hemorrhage resulting in displacement of basal ganglia components into the fourth ventricle.Conclusions:Sufficiently rapid intracerebral bleeding can dissect fragments of cerebrum and displace them long distances across the tentorial opening.

scholarly journals Toward asleep DBS: cortico-basal ganglia spectral and coherence activity during interleaved propofol/ketamine sedation mimics NREM/REM sleep activity

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jing Guang ◽  
Halen Baker ◽  
Orilia Ben-Yishay Nizri ◽  
Shimon Firman ◽  
Uri Werner-Reiss ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Rem Sleep ◽  
Standard Procedure ◽  
Low Frequency ◽  
Nrem Sleep ◽  
Sleep Cycle ◽  
Advanced Parkinson’S Disease ◽  
Low Frequency Power ◽  
The Brain ◽  
Frequency Power

AbstractDeep brain stimulation (DBS) is currently a standard procedure for advanced Parkinson’s disease. Many centers employ awake physiological navigation and stimulation assessment to optimize DBS localization and outcome. To enable DBS under sedation, asleep DBS, we characterized the cortico-basal ganglia neuronal network of two nonhuman primates under propofol, ketamine, and interleaved propofol-ketamine (IPK) sedation. Further, we compared these sedation states in the healthy and Parkinsonian condition to those of healthy sleep. Ketamine increases high-frequency power and synchronization while propofol increases low-frequency power and synchronization in polysomnography and neuronal activity recordings. Thus, ketamine does not mask the low-frequency oscillations used for physiological navigation toward the basal ganglia DBS targets. The brain spectral state under ketamine and propofol mimicked rapid eye movement (REM) and Non-REM (NREM) sleep activity, respectively, and the IPK protocol resembles the NREM-REM sleep cycle. These promising results are a meaningful step toward asleep DBS with nondistorted physiological navigation.

The topography, structure and incidence of mineralized bodies in the basal ganglia of the brain of cynomolgus monkeys (Macaca fascicularis)

1995 ◽  
Vol 29 (3) ◽  
pp. 276-281 ◽  
Author(s):  
P. F. Wadsworth ◽  
H. B. Jones ◽  
J. B. Cavanagh
Keyword(s):  
Basal Ganglia ◽  
Natural Occurrence ◽  
Optic Chiasma ◽  
Cynomolgus Monkeys ◽  
Small Vessels ◽  
Mammillary Bodies ◽  
Naturally Occurring ◽  
Toxicological Studies ◽  
One Year ◽  
The Brain

Whole coronal slices from 6 levels of the brain of 16 cynomolgus monkeys (8 control and 8 treated by daily gavage with a novel pharmaceutical agent for one year) were examined histologically. Mineralized bodies were identified only in coronal sections passing through the optic chiasma and mammillary bodies. Identical mineralized structures were present in the basal ganglia of both control and treated animals. The majority were seen in the globus pallidus, occasionally in the putamen and once in the nearby caudate nucleus. These structures were partially ferruginated and also partially calcified. They appeared to arise in relation to small vessels. They are part of the naturally occurring background pathology of several species of non-human primates and the incidence in this study (3/8 control and 5/8 treated) was approximately what might be expected from reports in the literature. Mineralized bodies of the basal ganglia of primates represent a spontaneous lesion with a characteristic distribution. They may cause confusion in interpretation of toxicological studies if their natural occurrence is not appreciated.

Putative neural consequences of captivity for elephants and cetaceans

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bob Jacobs ◽  
Heather Rally ◽  
Catherine Doyle ◽  
Lester O’Brien ◽  
Mackenzie Tennison ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Behavioral Health ◽  
Negative Impact ◽  
Well Being ◽  
Present Review ◽  
Large Mammals ◽  
Impoverished Environment ◽  
Neural Underpinnings ◽  
The Impact ◽  
The Brain

Abstract The present review assesses the potential neural impact of impoverished, captive environments on large-brained mammals, with a focus on elephants and cetaceans. These species share several characteristics, including being large, wide-ranging, long-lived, cognitively sophisticated, highly social, and large-brained mammals. Although the impact of the captive environment on physical and behavioral health has been well-documented, relatively little attention has been paid to the brain itself. Here, we explore the potential neural consequences of living in captive environments, with a focus on three levels: (1) The effects of environmental impoverishment/enrichment on the brain, emphasizing the negative neural consequences of the captive/impoverished environment; (2) the neural consequences of stress on the brain, with an emphasis on corticolimbic structures; and (3) the neural underpinnings of stereotypies, often observed in captive animals, underscoring dysregulation of the basal ganglia and associated circuitry. To this end, we provide a substantive hypothesis about the negative impact of captivity on the brains of large mammals (e.g., cetaceans and elephants) and how these neural consequences are related to documented evidence for compromised physical and psychological well-being.

Toluene-induced leukodystrophy from glue sniffing

2021 ◽  
pp. practneurol-2021-002942
Author(s):  
Yue Hui Lau ◽  
Ahmad Shahir Mawardi ◽  
Norzaini Rose Zain ◽  
Shanthi Viswanathan
Keyword(s):  
Basal Ganglia ◽  
Cognitive Decline ◽  
Early Recognition ◽  
Cerebellar Atrophy ◽  
Premature Mortality ◽  
History Of ◽  
The Brain

A 33-year-old man with a history of chronic toluene abuse through glue sniffing, developed tremors, cerebellar signs and cognitive decline. MR scan of the brain showed global cerebral and cerebellar atrophy with symmetrical T2-weighted hypointensities in the basal ganglia, thalami and midbrain. After stopping glue sniffing, his tremors, ataxia of gait, speech and cognition partially improved. Early recognition and intervention of toluene-induced leukodystrophy could prevent ongoing morbidity and premature mortality.

scholarly journals An Avian Basal Ganglia-Forebrain Circuit Contributes Differentially to Syllable Versus Sequence Variability of Adult Bengalese Finch Song

2009 ◽  
Vol 101 (6) ◽  
pp. 3235-3245 ◽  
Author(s):  
Cara M. Hampton ◽  
Jon T. Sakata ◽  
Michael S. Brainard
Keyword(s):  
Basal Ganglia ◽  
Syllable Structure ◽  
Skill Learning ◽  
Behavioral Variability ◽  
Neural Pathways ◽  
Sequence Variability ◽  
Social Modulation ◽  
The Social ◽  
Learned Behaviors ◽  
Magnocellular Nucleus

Behavioral variability is important for motor skill learning but continues to be present and actively regulated even in well-learned behaviors. In adult songbirds, two types of song variability can persist and are modulated by social context: variability in syllable structure and variability in syllable sequencing. The degree to which the control of both types of adult variability is shared or distinct remains unknown. The output of a basal ganglia-forebrain circuit, LMAN (the lateral magnocellular nucleus of the anterior nidopallium), has been implicated in song variability. For example, in adult zebra finches, neurons in LMAN actively control the variability of syllable structure. It is unclear, however, whether LMAN contributes to variability in adult syllable sequencing because sequence variability in adult zebra finch song is minimal. In contrast, Bengalese finches retain variability in both syllable structure and syllable sequencing into adulthood. We analyzed the effects of LMAN lesions on the variability of syllable structure and sequencing and on the social modulation of these forms of variability in adult Bengalese finches. We found that lesions of LMAN significantly reduced the variability of syllable structure but not of syllable sequencing. We also found that LMAN lesions eliminated the social modulation of the variability of syllable structure but did not detect significant effects on the modulation of sequence variability. These results show that LMAN contributes differentially to syllable versus sequence variability of adult song and suggest that these forms of variability are regulated by distinct neural pathways.

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