scholarly journals Dorsomedial prefrontal neural ensembles reflect changes in task utility that culminate in task quitting

2021 ◽  
Author(s):  
Blake Scott Porter ◽  
Kristin L Hillman
Keyword(s):  
Single Unit ◽  
Optimal Choice ◽  
Weight Lifting ◽  
Anterior Cingulate ◽  
Male Rat ◽  
Dorsomedial Prefrontal Cortex ◽  
Neural Ensembles ◽  
Behavioral States ◽  
Lifting Task ◽  
Over Time

When performing a physically demanding behavior, sometimes the optimal choice is to quit the behavior rather than persist in order to minimize energy expenditure for the benefits gained. The dorsomedial prefrontal cortex (dmPFC), consisting of the anterior cingulate cortex and secondary motor area, likely contributes towards such utility assessments. Here, we examined how male rat dmPFC single unit and ensemble level activity corresponded to changes in motivation and quitting in an effortful weight lifting task. Rats carried out two task paradigms: one that became progressively more physically demanding over time and a second fixed effort version. Rats could quit the task at any time. Dorsomedial PFC neurons were highly responsive to each behavioral stage of the task, consisting of rope pulling, reward retrieval, and reward area leaving. Activity was highest early in sessions, commensurate with the highest relative task utility, then decreased until the point of quitting. Neural ensembles consistently represented the sequential behavioral phases of the task. However, these representations were modified over time and became more distinct over the course of the session. These results suggest that dmPFC neurons represent behavioral states that are dynamically modified as behaviors lose their utility, culminating in task quitting.

scholarly journals Dorsomedial prefrontal neural ensembles reflect changes in task utility

2020 ◽  
Author(s):  
Blake S. Porter ◽  
Kristin L. Hillman
Keyword(s):  
Single Unit ◽  
Optimal Choice ◽  
Weight Lifting ◽  
Anterior Cingulate ◽  
Dorsomedial Prefrontal Cortex ◽  
Neural Ensembles ◽  
Behavioral States ◽  
Time And Energy ◽  
Task Representations ◽  
Lifting Task

AbstractWhen performing a physically demanding behavior, sometimes the optimal choice is to quit the behavior rather than persist and waste time and energy. The dorsomedial prefrontal cortex (dmPFC), consisting of the anterior cingulate cortex and secondary motor area, likely contributes towards such utility assessments. Here, we examined how rodent dmPFC single unit and ensemble level activity corresponded to changes in motivation and quitting in an effortful weight lifting task. Rats carried out two task paradigms: one that became progressively more physically demanding over time and a second fixed effort version. Rats could quit the task at any time. Dorsomedial PFC neurons were highly responsive to each behavioral stage of the task, consisting of rope pulling, reward retrieval, and reward area leaving. Activity was highest early in sessions, commensurate with the highest relative task utility, then decreased until the point of quitting. Neural ensembles showed stable task representations across the entirety of sessions. However, these representations drifted and became more distinct over the course of the session. These results suggest that dmPFC neurons represent behavioral states that are dynamically modified as behaviors lose their utility, culminating in task quitting.

The Path of Standard Albanian Language Formation

2018 ◽  
Vol 5 (2) ◽  
pp. 106-115
Author(s):  
Sindorela Doli Kryeziu
Keyword(s):  
Single Unit ◽  
Cultural Factors ◽  
Language History ◽  
Whole Process ◽  
History Of ◽  
Social And Cultural Factors ◽  
Cultural Body ◽  
Over Time ◽  
Language Literature

Abstract In our paper we will talk about the whole process of standardization of the Albanian language, where it has gone through a long historical route, for almost a century.When talking about standard Albanian language history and according to Albanian language literature, it is often thought that the Albanian language was standardized in the Albanian Language Orthography Congress, held in Tirana in 1972, or after the publication of the Orthographic Rules (which was a project at that time) of 1967 and the decisions of the Linguistic Conference, a conference of great importance that took place in Pristina, in 1968. All of these have influenced chronologically during a very difficult historical journey, until the standardization of the Albanian language.Considering a slightly wider and more complex view than what is often presented in Albanian language literature, we will try to describe the path (history) of the standard Albanian formation under the influence of many historical, political, social and cultural factors that are known in the history of the Albanian people. These factors have contributed to the formation of a common state, which would have, over time, a common standard language.It is fair to think that "all activity in the development of writing and the Albanian language, in the field of standardization and linguistic planning, should be seen as a single unit of Albanian culture, of course with frequent manifestations of specific polycentric organization, either because of divisions within the cultural body itself, or because of the external imposition"(Rexhep Ismajli," In Language and for Language ", Dukagjini, Peja, 1998, pp. 15-18.)

scholarly journals A novel weight lifting task for investigating effort and persistence in rats

2019 ◽  
Author(s):  
Blake Porter ◽  
Kristin L. Hillman
Keyword(s):  
Food Delivery ◽  
Video Tracking ◽  
Weight Lifting ◽  
Recording Equipment ◽  
Single Plane ◽  
Action Sequence ◽  
Total N ◽  
Lever Pressing ◽  
Lifting Task

AbstractHere we present a novel effort-based task for laboratory rats: the weight lifting task (WLT). Studies of effort expenditure in rodents have typically involved climbing barriers within T-mazes or operant lever pressing paradigms. These task designs have been successful for neuropharmacological and neurophysiological investigations, but both tasks involve simple action patterns prone to automatization. Furthermore, high climbing barriers present risk of injury to animals and/or tethered recording equipment. In the WLT, a rat is placed in a large rectangular arena and tasked with pulling a rope 30 cm to trigger food delivery at a nearby spout; weights can be added to the rope in 45 g increments to increase the intensity of effort. As compared to lever pressing and barrier jumping, 30 cm of rope pulling is a multi-step action sequence requiring sustained effort. The actions are carried out on the single plane of the arena floor, making it safer for the animal and more suitable for tethered equipment and video tracking. A microcontroller and associated sensors enable precise timestamping of specific behaviors to synchronize with electrophysiological recordings. The rope and reward spout are spatially segregated to allow for spatial discrimination of the effort zone and the reward zone. We validated the task across five cohorts of rats (total n=35) and report consistent behavioral metrics. The WLT is well-suited for neuropharmacological and/or in vivo neurophysiological investigations surrounding effortful behaviors, particularly when wanting to probe different aspects of effort expenditure (intensity vs. duration).

scholarly journals The refined biomimetic NeuroDigm GEL™ Model of neuropathic pain in the mature rat

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2516 ◽  
Author(s):  
Mary R. Hannaman ◽  
Douglas A. Fitts ◽  
Rose M. Doss ◽  
David E. Weinstein ◽  
Joseph L. Bryant
Keyword(s):  
Neuropathic Pain ◽  
Recombinant Human Erythropoietin ◽  
Tissue Injury ◽  
Soft Tissue Injury ◽  
Pain Behavior ◽  
Neural Regeneration ◽  
Male Rat ◽  
Human Erythropoietin ◽  
Neural Remodeling ◽  
Over Time

Background:Many humans suffering with chronic pain have no clinical evidence of a lesion or disease. They are managed with a morass of drugs and invasive procedures. Opiates usually become less effective over time. In many, their persistent pain occurs after the healing of a soft tissue injury. Current animal models of neuropathic pain typically create direct neural damage with open surgeries using ligatures, neurectomies, chemicals or other forms of deliberate trauma. However, we have observed clinically that after an injury in humans, the naturally occurring process of tissue repair can cause chronic neural pain.Methods:We demonstrate how the refined biomimetic NeuroDigm GEL™ Model, in the mature male rat, gradually induces neuropathic pain behavior with a nonsurgical percutaneous implant of tissue-derived hydrogel in the musculo-fascial tunnel of the distal tibial nerve. Morphine, Celecoxib, Gabapentin and Duloxetine were each screened in the model three times each over 5 months after pain behaviors developed. A pilot study followed in which recombinant human erythropoietin was applied to the GEL neural procedure site.Results:The GEL Model gradually developed neuropathic pain behavior lasting months. Morphine, initially effective, had less analgesia over time. Celecoxib produced no analgesia, while gabapentin and duloxetine at low doses had profound analgesia at all times tested. The injected erythropoietin markedly decreased bilateral pain behavior that had been present for over 4 months. Histology revealed a site of focal neural remodeling, with neural regeneration, as in human biopsies.Conclusion:The refined NeuroDigm GEL™ Model induces localized neural remodeling resulting in robust neuropathic pain behavior. The analgesics responses in this model reflect known responses of humans with neuropathic pain. The targeted recombinant human erythropoietin appears to heal the ectopic focal neural site, as demonstrated by the extinguishing of neuropathic pain behavior present for over 4 months.

AN ETHOGRAM OF WHITE LEGHORN-TYPE HENS IN BATTERY CAGES

1990 ◽  
Vol 70 (3) ◽  
pp. 751-760 ◽  
Author(s):  
A. B. WEBSTER ◽  
J. F. HURNIK
Keyword(s):  
Key Words ◽  
Egg Production ◽  
Age Effect ◽  
Feed Consumption ◽  
Behavioral Adaptation ◽  
White Leghorn ◽  
Video Recordings ◽  
Behavioral States ◽  
Physical Displacement ◽  
Over Time

The purpose of this study was to record the ethogram of White Leghorn-type hens in cages and to note changes in behavior over the course of the laying period. Three hundred and eighty-four hens derived from two male parental stocks were randomly assigned as pairs to the cages of two three-tiered, semi-stairstep batteries. Hens within pairs were of the same stock, and the batteries were in the same room. The laying phase comprised 13 28-d periods and on the first 4 d of periods 1, 3, 5, 7, 9 and 11 video recordings were made of eight cages per day. Each cage was observed on 1 d only. The levels of occurrence of a variety of behavioral states were estimated from 60 records of the behavior of each hen obtained over an 8-h interval. Head flicking was the most prevalent of its group of mutually exclusive behavioral states, followed by eating and preening. Cage pecking appeared stereotyped in many hens, but, at a frequency of 5% of observations, was not unusually prevalent. Bobbing was primarily a prelaying behavior indicative of the restlessness prior to oviposition typical of White Leghorn hens in cages. Hens were on their feet for more than 75% of the time of observation. Physical displacement of a hen by its cagemate was commonplace. Eating was negatively correlated with head flicking and preening. Walking and bobbing were positively correlated with physical displacement. Hens became less active with time in cages, possibly due to an age effect or to behavioral adaptation to the cage environment. A second trend in behavior over time may be related to changes in levels of egg production or feed consumption. Key words: Ethogram, behavior, laying hen, battery cage

scholarly journals Transient uterine hypercontractility causes fetal cerebral oxidative stress and enduring mitochondrial and behavioral abnormalities in adolescent male rat offspring

2019 ◽  
Author(s):  
Arvind Palanisamy ◽  
Tusar Giri ◽  
Jia Jiang ◽  
Annie Bice ◽  
James D. Quirk ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Neurodevelopmental Disorders ◽  
Lactate Concentration ◽  
Fetal Brain ◽  
Specific Effect ◽  
Anterior Cingulate ◽  
Adolescent Male ◽  
Male Rat ◽  
The Impact ◽  
Placental Ischemia

AbstractThe impact of transient ischemic-hypoxemic insults on the developing fetal brain is poorly understood despite evidence suggesting an association with neurodevelopmental disorders such as schizophrenia and autism. To address this, we designed an aberrant uterine hypercontractility paradigm with oxytocin to better assess the consequences of acute, but transient, placental ischemia-hypoxemia in term pregnant rats. Using MRI imaging, we confirmed that oxytocin-induced aberrant uterine hypercontractility significantly compromised uteroplacental perfusion. This was supported by the observation of oxidative stress and increased lactate concentration in the fetal brain. Genes related to oxidative stress pathways were significantly upregulated in male, but not female, offspring 1 h after oxytocin-induced placental ischemia-hypoxemia. Persistent upregulation of select mitochondrial electron transport chain complex proteins in the anterior cingulate cortex of adolescent male offspring suggested that this sex-specific effect was enduring. Functionally, offspring exposed to oxytocin-induced uterine hypercontractility showed male-specific abnormalities in social behavior with associated region-specific changes in gene expression and functional cortical connectivity. Our findings, therefore, indicate that even transient but severe placental ischemia-hypoxemia could be detrimental to the developing brain and point to a possible mitochondrial link between intrauterine asphyxia and neurodevelopmental disorders.

scholarly journals Building the Tourist Destination Through Multiple Semiotic Modes

2021 ◽  
Vol 11 (4) ◽  
pp. 83
Author(s):  
Olga Denti
Keyword(s):  
Single Unit ◽  
Functional Approach ◽  
Mobile Technologies ◽  
Visual Design ◽  
Cultural Meanings ◽  
Text And Image ◽  
Tourist Destination ◽  
Tourist Gaze ◽  
The Relationship ◽  
Over Time

Over time, multiple semiotic modes have contributed in different ways to the construction and exchange of cultural meanings in Tourism Discourse. This has required the analysis and understanding of the modes employed and the recontextualization and adaptation of texts and images, especially to the new web genres. Nowadays, the tourist experience is mediated by personal, digital, and mobile technologies, which redirect the tourist gaze and become the mediator between the traveler and the tourist destination. Consequently, the tourism text must be considered as a single unit, where different semiotic resources intermingle to enhance its communicative strength. The present study will attempt to propose a methodology to read and write tourism texts in a comprehensive and effective way. It will start by focusing on the relationship between text and image to see how they co-exist in the page and in the way the page is arranged. Then, it will apply a functional approach to the analysis of such semiotic units. The result will show how the boundaries between image and text have become blurred, and textuality is built less through verbal syntax and more through rhetorical visual design.

scholarly journals Comparative analysis of the modulation of perineuronal nets in the prefrontal cortex of rats during protracted withdrawal from cocaine, heroin and sucrose self-administration

2020 ◽  
Author(s):  
David Roura-Martínez ◽  
Paula Díaz-Bejarano ◽  
Marcos Ucha ◽  
Emilio Ambrosio ◽  
Alejandro Higuera-Matas
Keyword(s):  
Prefrontal Cortex ◽  
Brain Plasticity ◽  
Insular Cortex ◽  
Vital Role ◽  
Perineuronal Nets ◽  
Infralimbic Cortex ◽  
Self Administration ◽  
Dorsomedial Prefrontal Cortex ◽  
Drug Classes ◽  
Over Time

ABSTRACTRelapse into drug use is a significant problem for people recovering from addiction. The ability that conditioned cues have to reinstate and reinvigorate drug-seeking is potentiated over time (incubation of seeking), posing an additional difficulty for maintaining abstinence. While the prefrontal cortex has been involved in the incubation phenomenon and the extracellular matrix, perineuronal nets (PNN) in particular, may play a vital role in brain plasticity associated to drug relapse, there are no comparative analyses between different drug classes and natural reinforcers. Here, we compare the effects of early (1 day) and protracted (30 days) withdrawal from to cocaine, heroin and sucrose self-administration on the PNN content of different territories of the prefrontal cortex of male Lewis rats. Our results show that cocaine self-administration and protracted withdrawal decreased PNN content in the prelimbic cortex. Also, heroin self-administration increased PNN content in the infralimbic cortex, but this effect was lost after 30 days of withdrawal. Heroin self-administration also decreased PNNs in the insula, an effect that remained even after protracted withdrawal from the drug. Finally, the self-administration of sucrose-sweetened water decreased PNN content in the dorsomedial prefrontal cortex and increased PNNs in the insular cortex, which was still evident after protracted withdrawal. Our results show that three different rewards with specific pharmacological and physiological actions differentially modulate PNNs in specific areas of the rodent prefrontal cortex with potential implications for the incubation of seeking phenomenon.

scholarly journals Multi-model mapping of phonemic fluency

2021 ◽  
Author(s):  
Lisa Cipolotti ◽  
Tianbo Xu ◽  
Bronson Harry ◽  
Joe Mole ◽  
Grace Lakey ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Small Sample Size ◽  
Small Sample ◽  
Anterior Cingulate ◽  
Functional Region ◽  
Phonemic Fluency ◽  
Number Of Patients ◽  
Lesion Symptom Mapping ◽  
Subcortical Regions ◽  
Over Time

Abstract The voluntary generation of non-overlearned responses is usually assessed with phonemic fluency. Like most frontal tasks, it draws upon different complex processes and systems whose precise nature is still incompletely understood. Many claimed aspects regarding the pattern of phonemic fluency performance and its underlying anatomy remain controversial. Major limitations of past investigations include small sample size, scant analysis of phonemic output and methodologically insufficient lesion analyses approaches. We investigated a large number of patients with focal unilateral right or left frontal (n = 110) or posterior (n = 100) or subcortical (n = 65) lesions imaged with magnetic resonance or computed tomography and compared their performance on the number of overall responses, words produced over time, extremely infrequent/unknown words and inappropriate words generated. We also employed, for the first time parcel-based lesion symptom mapping, tract-wise statistical analysis as well as Bayesian multivariate analysis based on meta-analytically defined functional region of interest, including their interactions. We found that left frontal damage was associated with greater impairment than right frontal or posterior damage on overall fluency performance, suggesting that phonemic fluency shows specificity to frontal lesions. We also found that subcorticals, similar to frontals, performed significantly worse than posteriors on overall performance suggesting that subcortical regions are also involved. However, only frontal effects were found for words produced over time, extremely infrequent/unknown and inappropriate words. Parcel-based lesion symptom mapping analysis found that worse fluency performance was associated with damage to the posterior segment of the left frontal middle and superior gyrus, the left dorsal anterior cingulate gyrus and caudate nucleus. Tract-wise statistical analysis revealed that disconnections of left frontal tracts are critical. Bayesian multivariate models of lesions and disconnectome maps implicated left middle and inferior frontal and left dorsomedial frontal regions. Our study suggests that a set of well localised left frontal areas together with subcortical regions and several left frontal tracts are critical for word generation. We speculate that a left lateralized network exists. It involves medial, frontal regions supporting the process of energization, which sustains activation for the duration of the task and middle and inferior frontal regions concerned with selection, required due to the competition produced by associated stored words, respectively. The methodology adopted represents a promising and empirically robust approach in furthering our understanding of the neurocognitive architecture underpinning executive processes.

scholarly journals Neural mechanisms of economic commitment in the human medial prefrontal cortex

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Konstantinos Tsetsos ◽  
Valentin Wyart ◽  
S Paul Shorkey ◽  
Christopher Summerfield
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Neural Mechanisms ◽  
Anterior Cingulate ◽  
Dorsal Anterior Cingulate Cortex ◽  
Financial Return ◽  
Economic Decisions ◽  
Decision Biases ◽  
Stimulus Value ◽  
Over Time

Neurobiologists have studied decisions by offering successive, independent choices between goods or gambles. However, choices often have lasting consequences, as when investing in a house or choosing a partner. Here, humans decided whether to commit (by acceptance or rejection) to prospects that provided sustained financial return. BOLD signals in the rostral medial prefrontal cortex (rmPFC) encoded stimulus value only when acceptance or rejection was deferred into the future, suggesting a role in integrating value signals over time. By contrast, the dorsal anterior cingulate cortex (dACC) encoded stimulus value only when participants rejected (or deferred accepting) a prospect. dACC BOLD signals reflected two decision biases–to defer commitments to later, and to weight potential losses more heavily than gains–that (paradoxically) maximised reward in this task. These findings offer fresh insights into the pressures that shape economic decisions, and the computation of value in the medial prefrontal cortex.

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