scholarly journals Rational regulation of water-seeking effort in rodents

2021 ◽  
Vol 118 (48) ◽  
pp. e2111742118
Author(s):  
Pamela Reinagel
Keyword(s):  
Labor Supply ◽  
Temporal Dynamics ◽  
Neural Mechanisms ◽  
Laboratory Animals ◽  
Closed Economy ◽  
Voluntary Work ◽  
Glutamatergic Neurons ◽  
Elasticity Of Demand ◽  
Human Labor ◽  
Long Timescales

In the laboratory, animals’ motivation to work tends to be positively correlated with reward magnitude. But in nature, rewards earned by work are essential to survival (e.g., working to find water), and the payoff of that work can vary on long timescales (e.g., seasonally). Under these constraints, the strategy of working less when rewards are small could be fatal. We found that instead, rats in a closed economy did more work for water rewards when the rewards were stably smaller, a phenomenon also observed in human labor supply curves. Like human consumers, rats showed elasticity of demand, consuming far more water per day when its price in effort was lower. The neural mechanisms underlying such “rational” market behaviors remain largely unexplored. We propose a dynamic utility maximization model that can account for the dependence of rat labor supply (trials/day) on the wage rate (milliliter/trial) and also predict the temporal dynamics of when rats work. Based on data from mice, we hypothesize that glutamatergic neurons in the subfornical organ in lamina terminalis continuously compute the instantaneous marginal utility of voluntary work for water reward and causally determine the amount and timing of work.

Stimulus Specificity and Temporal Dynamics of Working Memory for Visual Motion

2003 ◽  
Vol 90 (4) ◽  
pp. 2757-2762 ◽  
Author(s):  
Tatiana Pasternak ◽  
Daniel Zaksas
Keyword(s):  
Visual Motion ◽  
Temporal Dynamics ◽  
Random Motion ◽  
Neural Mechanisms ◽  
Precise Location ◽  
Storage Mechanism ◽  
Motion Stimulus ◽  
Selective Interference ◽  
Stimulus Specificity ◽  
Stimulus Direction

When asked to compare two moving stimuli separated by a delay, observers must not only identify stimulus direction but also store it in memory. We examined the properties of this storage mechanism in two macaque monkeys by sequentially presenting two random-dot stimuli, sample and test, in opposite hemifields and introducing a random-motion mask during the delay. The mask interfered with performance only at the precise location of the test, 100–200 ms after the start of the delay, and when its size and speed matched those of the remembered sample. This selective interference suggests that the representation of the motion stimulus in memory preserves its direction, speed, and size and is most fragile shortly after the completion of the encoding phase of the task. This precise preservation of sensory attributes of the motion stimulus suggests that the neural mechanisms involved in the processing of visual motion may also be involved in its storage.

scholarly journals Learning and Memory: Considerations for Toxicology

1989 ◽  
Vol 8 (1) ◽  
pp. 213-223 ◽  
Author(s):  
David B. Peele
Keyword(s):  
Learning And Memory ◽  
Cost Effective ◽  
Test Methods ◽  
Neural Mechanisms ◽  
Experimental Designs ◽  
Laboratory Animals ◽  
Primary Screening ◽  
Chemically Induced ◽  
Selection Of ◽  
Meaningful Data

The goal of this article is to outline a strategy for assessing chemical-induced dysfunction of learning and memory in laboratory animals. Toward that end, several questions are raised, including if tests of learning and memory should be included in a primary screening effort, what considerations should guide the selection of particular test methods, and experimental designs. Examples are provided demonstrating that tests of learning and memory can be simple and cost-effective, yet still provide meaningful data on the specificity of effects and on the neural mechanisms involved in chemically induced neurotoxicity.

Processing of visual semantic information to concrete words: temporal dynamics and neural mechanisms indicated by event-related brain potentials

2005 ◽  
Vol 22 (3-4) ◽  
pp. 364-386 ◽  
Author(s):  
Hein T. van Schie ◽  
Albertus A. Wijers ◽  
Rogier B. Mars ◽  
Jeroen S. Benjamins ◽  
Laurie A. Stowe
Keyword(s):  
Semantic Information ◽  
Temporal Dynamics ◽  
Neural Mechanisms ◽  
Brain Potentials ◽  
Concrete Words

Evidence of Change of Intention in Picking Situations

2015 ◽  
Vol 27 (11) ◽  
pp. 2133-2146 ◽  
Author(s):  
Ariel Furstenberg ◽  
Assaf Breska ◽  
Haim Sompolinsky ◽  
Leon Y. Deouell
Keyword(s):  
Free Choice ◽  
Temporal Dynamics ◽  
Neural System ◽  
Neural Mechanisms ◽  
Left Button ◽  
Readiness Potentials ◽  
The Face ◽  
Intention To Move ◽  
Intention Formation ◽  
Lateralized Readiness Potentials

Intending to perform an action and then immediately executing it is a mundane process. The cognitive and neural mechanisms involved in this process of “proximal” intention formation and execution, in the face of multiple options to choose from, are not clear, however. Especially, it is not clear how intentions are formed when the choice makes no difference. Here we used behavioral and electrophysiological measures to investigate the temporal dynamics of proximal intention formation and “change of intention” in a free picking scenario, in which the alternatives are on a par for the participant. Participants pressed a right or left button following either an instructive visible arrow cue or a visible neutral “free-choice” cue, both preceded by a masked arrow prime. The goal of the prime was to induce a bias toward pressing the left or right button. Presumably, when the choice is arbitrary, such bias should determine the decision. EEG lateralized readiness potentials and EMG measurements revealed that the prime indeed induced an intention to move in one direction. However, we discovered a signature of “change of intention” in both the Instructed and Free-choice decisions. These results suggest that, even in arbitrary choices, biases present in the neural system for choosing one or another option may be overruled and point to a curious “picking deliberation” phenomenon. We discuss a possible neural scenario that could explain this phenomenon.

scholarly journals Cue Competition Affects Temporal Dynamics of Edge-assignment in Human Visual Cortex

2011 ◽  
Vol 23 (3) ◽  
pp. 631-644 ◽  
Author(s):  
Joseph L. Brooks ◽  
Stephen E. Palmer
Keyword(s):  
Temporal Dynamics ◽  
Neural Mechanisms ◽  
Cue Competition ◽  
Relative Depth ◽  
Competition And Cooperation ◽  
Neural Representations ◽  
Winner Take All ◽  
Take All ◽  
Figural Assignment ◽  
Ground Organization

Edge-assignment determines the perception of relative depth across an edge and the shape of the closer side. Many cues determine edge-assignment, but relatively little is known about the neural mechanisms involved in combining these cues. Here, we manipulated extremal edge and attention cues to bias edge-assignment such that these two cues either cooperated or competed. To index their neural representations, we flickered figure and ground regions at different frequencies and measured the corresponding steady-state visual-evoked potentials (SSVEPs). Figural regions had stronger SSVEP responses than ground regions, independent of whether they were attended or unattended. In addition, competition and cooperation between the two edge-assignment cues significantly affected the temporal dynamics of edge-assignment processes. The figural SSVEP response peaked earlier when the cues causing it cooperated than when they competed, but sustained edge-assignment effects were equivalent for cooperating and competing cues, consistent with a winner-take-all outcome. These results provide physiological evidence that figure–ground organization involves competitive processes that can affect the latency of figural assignment.

scholarly journals Psychological and neural mechanisms of relapse

2008 ◽  
Vol 363 (1507) ◽  
pp. 3147-3158 ◽  
Author(s):  
Jane Stewart
Keyword(s):  
Drug Exposure ◽  
Dopaminergic System ◽  
Drug Effects ◽  
Corticotropin Releasing Factor ◽  
Stressful Events ◽  
Neural Mechanisms ◽  
Laboratory Animals ◽  
Anatomical Studies ◽  
The Relationship ◽  
The Brain

Relapse, the resumption of drug taking after periods of abstinence, remains the major problem for the treatment of addiction. Even when drugs are unavailable for long periods or when users are successful in curbing their drug use for extended periods, individuals remain vulnerable to events that precipitate relapse. Behavioural studies in humans and laboratory animals show that drug-related stimuli, drugs themselves and stressors are powerful events for the precipitation of relapse. Molecular, neurochemical and anatomical studies have identified lasting neural changes that arise from mere exposure to drugs and other enduring changes that arise from learning about the relationship between drug-related stimuli and drug effects. Chronic drug exposure increases sensitivity of some systems of the brain to the effects of drugs and stressful events. These changes, combined with those underlying conditioning and learning, perpetuate vulnerability to drug-related stimuli. Circuits of the brain involved are those of the mesocorticolimbic dopaminergic system and its glutamatergic connections, and the corticotropin-releasing factor and noradrenergic systems of the limbic brain. This paper reviews advances in our understanding of how these systems mediate the effects of events that precipitate relapse and of how lasting changes in these systems can perpetuate vulnerability to relapse.

Neural mechanisms and temporal dynamics of performance monitoring

2014 ◽  
Vol 18 (5) ◽  
pp. 259-267 ◽  
Author(s):  
Markus Ullsperger ◽  
Adrian G. Fischer ◽  
Roland Nigbur ◽  
Tanja Endrass
Keyword(s):  
Performance Monitoring ◽  
Temporal Dynamics ◽  
Neural Mechanisms

scholarly journals Dynamic dopaminergic activity controls the timing of self-timed movement

2020 ◽  
Author(s):  
Allison E. Hamilos ◽  
Giulia Spedicato ◽  
Ye Hong ◽  
Fangmiao Sun ◽  
Yulong Li ◽  
...  
Keyword(s):  
Movement Time ◽  
Neural Mechanisms ◽  
Dopamine Neurons ◽  
Movement Initiation ◽  
Movement Timing ◽  
Baseline Activity ◽  
Pharmacological Studies ◽  
The Moment ◽  
Long Timescales ◽  
Threshold Process

SUMMARYDeciding when to initiate action is essential to survival. Insights from movement disorders and pharmacological studies implicate the neurotransmitter dopamine as a regulator of movement timing, but the underlying neural mechanisms are not understood. Here we show dynamic dopaminergic signaling over seconds-long timescales controls movement timing in mice. Animals were trained to initiate licking after a self-timed interval following a start-timing cue. Surprisingly, dopaminergic signals ramped-up slowly between the start-timing cue and the self-timed movement, with the slope predicting the movement time on single trials. Steeply rising signals preceded early lick-initiation, whereas slowly rising signals preceded later initiation, reminiscent of a ramp-to-threshold process. Higher baseline activity also predicted earlier self-timed movements. Optogenetic activation of dopamine neurons during self-timing caused systematic early-shifting of movement initiation, whereas inhibition caused late-shifting. These results reveal a causal role for dynamic dopaminergic signaling unfolding over seconds in controlling the moment-by-moment decision of when to move.

scholarly journals Distance to Healthy Metabolic and Cardiovascular Dynamics From Fetal Heart Rate Scale-Dependent Features in Pregnant Sheep Model of Human Labor Predicts the Evolution of Acidemia and Cardiovascular Decompensation

2021 ◽  
Vol 9 ◽  
Author(s):  
Stephane G. Roux ◽  
Nicolas B. Garnier ◽  
Patrice Abry ◽  
Nathan Gold ◽  
Martin G. Frasch
Keyword(s):  
Heart Rate ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Temporal Dynamics ◽  
Sampling Rate ◽  
Well Being ◽  
Local Analysis ◽  
Arterial Blood ◽  
Pregnant Sheep ◽  
Human Labor

The overarching goal of the present work is to contribute to the understanding of the relations between fetal heart rate (FHR) temporal dynamics and the well-being of the fetus, notably in terms of predicting the evolution of lactate, pH and cardiovascular decompensation (CVD). It makes uses of an established animal model of human labor, where 14 near-term ovine fetuses subjected to umbilical cord occlusions (UCO) were instrumented to permit regular intermittent measurements of metabolites lactate and base excess, pH, and continuous recording of electrocardiogram (ECG) and systemic arterial blood pressure (to identify CVD) during UCO. ECG-derived FHR was digitized at the sampling rate of 1,000 Hz and resampled to 4 Hz, as used in clinical routine. We focused on four FHR variability features which are tunable to temporal scales of FHR dynamics, robustly computable from FHR sampled at 4 Hz and within short-time sliding windows, hence permitting a time-dependent, or local, analysis of FHR which helps dealing with signal noise. Results show the sensitivity of the proposed features for early detection of CVD, correlation to metabolites and pH, useful for early acidosis detection and the importance of coarse time scales (2.5–8 s) which are not disturbed by the low FHR sampling rate. Further, we introduce the performance of an individualized self-referencing metric of the distance to healthy state, based on a combination of the four features. We demonstrate that this novel metric, applied to clinically available FHR temporal dynamics alone, accurately predicts the time occurrence of CVD which heralds a clinically significant degradation of the fetal health reserve to tolerate the trial of labor.

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