scholarly journals Complex spikes encode reward expectation signals during visuomotor association learning

2019 ◽  
Author(s):  
Naveen Sendhilnathan ◽  
Anna Ipata ◽  
Michael E. Goldberg
Keyword(s):  
Stimulus Onset ◽  
Higher Order ◽  
Independent Manner ◽  
General Role ◽  
Order Processing ◽  
Association Learning ◽  
Reward Delivery ◽  
Spike Signals ◽  
Complex Spikes

AbstractClimbing fiber input to Purkinje cells has been thought to instruct learning related changes in simple spikes and cause behavioral changes through an error-based learning mechanism. Although, this framework explains simple motor learning, it cannot be extended to learning higher-order skills. Recently the cerebellum has been implicated in a variety of cognitive tasks and reward-based learning. Here we show that when a monkey learns a new visuomotor association, complex spikes predict the time of the beginning of the trial in a learning independent manner as well as encode a learning contingent reward expectation signal after the stimulus onset and reward delivery. These complex spike signals are unrelated to and were unlikely to instruct the reward based signal found in the simple spikes. Our results provide a more general role of complex spikes in learning and higher-order processing while gathering evidence for their participation in reward based learning.

scholarly journals Mid-lateral cerebellar complex spikes encode multiple independent reward-related signals during reinforcement learning

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Naveen Sendhilnathan ◽  
Anna Ipata ◽  
Michael E. Goldberg
Keyword(s):  
Reinforcement Learning ◽  
Stimulus Onset ◽  
Cell Type ◽  
Independent Manner ◽  
Distinct Cell Type ◽  
Information Encoding ◽  
Cognitive Behaviors ◽  
Wide Range ◽  
Neural Information ◽  
Complex Spikes

AbstractAlthough the cerebellum has been implicated in simple reward-based learning recently, the role of complex spikes (CS) and simple spikes (SS), their interaction and their relationship to complex reinforcement learning and decision making is still unclear. Here we show that in a context where a non-human primate learned to make novel visuomotor associations, classifying CS responses based on their SS properties revealed distinct cell-type specific encoding of the probability of failure after the stimulus onset and the non-human primate’s decision. In a different context, CS from the same cerebellar area also responded in a cell-type and learning independent manner to the stimulus that signaled the beginning of the trial. Both types of CS signals were independent of changes in any motor kinematics and were unlikely to instruct the concurrent SS activity through an error based mechanism, suggesting the presence of context dependent, flexible, multiple independent channels of neural encoding by CS and SS. This diversity in neural information encoding in the mid-lateral cerebellum, depending on the context and learning state, is well suited to promote exploration and acquisition of wide range of cognitive behaviors that entail flexible stimulus-action-reward relationships but not necessarily motor learning.

scholarly journals Cerebellar climbing fibers encode expected reward size

2019 ◽  
Author(s):  
Noga Larry ◽  
Merav Yarkoni ◽  
Adi Lixenberg ◽  
Mati Joshua
Keyword(s):  
Associative Learning ◽  
Error Correction ◽  
Eye Movement ◽  
Climbing Fiber ◽  
Climbing Fibers ◽  
Successful Completion ◽  
General Role ◽  
Reward Delivery

Climbing fiber inputs to the cerebellum encode error signals that instruct learning. Recently, evidence has accumulated to suggest that the cerebellum is also involved in the processing of reward. To study how rewarding events are encoded, we recorded the activity of climbing fibers when monkeys were engaged in an eye movement task. At the beginning of each trial, the monkeys were cued the size of the reward that would be delivered upon successful completion of the trial. We found increased climbing fiber activity during cue presentation when information about reward size was first made available. Reward size did not modulate activity at reward delivery. These results indicate that climbing fibers encode the expected reward size and suggest a general role of the cerebellum in associative learning beyond error correction.

scholarly journals Cerebellar climbing fibers encode expected reward size

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Noga Larry ◽  
Merav Yarkoni ◽  
Adi Lixenberg ◽  
Mati Joshua
Keyword(s):  
Eye Movements ◽  
Error Correction ◽  
Large Reward ◽  
Small Reward ◽  
Climbing Fiber ◽  
Climbing Fibers ◽  
Successful Completion ◽  
General Role ◽  
Reward Delivery

Climbing fiber inputs to the cerebellum encode error signals that instruct learning. Recently, evidence has accumulated to suggest that the cerebellum is also involved in the processing of reward. To study how rewarding events are encoded, we recorded the activity of climbing fibers when monkeys were engaged in an eye movement task. At the beginning of each trial, the monkeys were cued to the size of the reward that would be delivered upon successful completion of the trial. Climbing fiber activity increased when the monkeys were presented with a cue indicating a large reward, but not a small reward. Reward size did not modulate activity at reward delivery or during eye movements. Comparison between climbing fiber and simple spike activity indicated different interactions for coding of movement and reward. These results indicate that climbing fibers encode the expected reward size and suggest a general role of the cerebellum in associative learning beyond error correction.

Dissent in the Atlantic World, 1787–1830

2018 ◽  
Author(s):  
Katherine Carté Engel
Keyword(s):  
United States ◽  
African Americans ◽  
First Amendment ◽  
Church And State ◽  
State Level ◽  
The United States ◽  
American Population ◽  
Simple Fact ◽  
General Role

The very term ‘Dissenter’ became problematic in the United States, following the passing of the First Amendment. The formal separation of Church and state embodied in the First Amendment was followed by the ending of state-level tax support for churches. None of the states established after 1792 had formal religious establishments. Baptists, Congregationalists, Presbyterians, and Methodists accounted for the majority of the American population both at the beginning and end of this period, but this simple fact masks an important compositional shift. While the denominations of Old Dissent declined relatively, Methodism grew quickly, representing a third of the population by 1850. Dissenters thus faced several different challenges. Primary among these were how to understand the idea of ‘denomination’ and also the more general role of institutional religion in a post-establishment society. Concerns about missions, and the positions of women and African Americans are best understood within this context.

scholarly journals NLRP7 Promotes Choriocarcinoma Growth and Progression through the Establishment of an Immunosuppressive Microenvironment

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2999
Author(s):  
Deborah Reynaud ◽  
Roland Abi Nahed ◽  
Nicolas Lemaitre ◽  
Pierre-Adrien Bolze ◽  
Wael Traboulsi ◽  
...  
Keyword(s):  
Immune Response ◽  
Tumor Cells ◽  
Major Gene ◽  
Critical Role ◽  
Orthotopic Model ◽  
Independent Manner ◽  
Maternal Immune Response ◽  
The Impact

The inflammatory gene NLRP7 is the major gene responsible for recurrent complete hydatidiform moles (CHM), an abnormal pregnancy that can develop into gestational choriocarcinoma (CC). However, the role of NLRP7 in the development and immune tolerance of CC has not been investigated. Three approaches were employed to define the role of NLRP7 in CC development: (i) a clinical study that analyzed human placenta and sera collected from women with normal pregnancies, CHM or CC; (ii) an in vitro study that investigated the impact of NLRP7 knockdown on tumor growth and organization; and (iii) an in vivo study that used two CC mouse models, including an orthotopic model. NLRP7 and circulating inflammatory cytokines were upregulated in tumor cells and in CHM and CC. In tumor cells, NLRP7 functions in an inflammasome-independent manner and promoted their proliferation and 3D organization. Gravid mice placentas injected with CC cells invalidated for NLRP7, exhibited higher maternal immune response, developed smaller tumors, and displayed less metastases. Our data characterized the critical role of NLRP7 in CC and provided evidence of its contribution to the development of an immunosuppressive maternal microenvironment that not only downregulates the maternal immune response but also fosters the growth and progression of CC.

scholarly journals Tethering-induced destabilization and ATP-binding for tandem RRM domains of ALS-causing TDP-43 and hnRNPA1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mei Dang ◽  
Yifan Li ◽  
Jianxing Song
Keyword(s):  
Conformational Dynamics ◽  
Md Simulations ◽  
Atp Binding ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Nucleic Acid Binding ◽  
General Role ◽  
Nmr Characterization ◽  
Lateral Sclerosis

AbstractTDP-43 and hnRNPA1 contain tandemly-tethered RNA-recognition-motif (RRM) domains, which not only functionally bind an array of nucleic acids, but also participate in aggregation/fibrillation, a pathological hallmark of various human diseases including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), alzheimer's disease (AD) and Multisystem proteinopathy (MSP). Here, by DSF, NMR and MD simulations we systematically characterized stability, ATP-binding and conformational dynamics of TDP-43 and hnRNPA1 RRM domains in both tethered and isolated forms. The results reveal three key findings: (1) upon tethering TDP-43 RRM domains become dramatically coupled and destabilized with Tm reduced to only 49 °C. (2) ATP specifically binds TDP-43 and hnRNPA1 RRM domains, in which ATP occupies the similar pockets within the conserved nucleic-acid-binding surfaces, with the affinity slightly higher to the tethered than isolated forms. (3) MD simulations indicate that the tethered RRM domains of TDP-43 and hnRNPA1 have higher conformational dynamics than the isolated forms. Two RRM domains become coupled as shown by NMR characterization and analysis of inter-domain correlation motions. The study explains the long-standing puzzle that the tethered TDP-43 RRM1–RRM2 is particularly prone to aggregation/fibrillation, and underscores the general role of ATP in inhibiting aggregation/fibrillation of RRM-containing proteins. The results also rationalize the observation that the risk of aggregation-causing diseases increases with aging.

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