scholarly journals A ventral striatal-orexin/hypocretin circuit modulates approach but not consumption of food

2020 ◽  
Author(s):  
Caitlin S. Mitchell ◽  
Simon D. Fisher ◽  
Jiann W. Yeoh ◽  
Amy J. Pearl ◽  
Nicholas J. Burton ◽  
...  
Keyword(s):  
Consummatory Behavior ◽  
Nucleus Accumbens Shell ◽  
Metabolic State ◽  
Cell Recruitment ◽  
Motivated Behavior ◽  
Cell Type Specific ◽  
Freely Behaving ◽  
Increased Activity ◽  
Relevant Factors

SummaryFeeding is at once both a basic biological need and a function set in a complex system of competing motivational drivers. Orexin/hypocretin neurons are located exclusively within the lateral hypothalamus (LH) and are commonly implicated in feeding, arousal, and motivated behavior, although largely based on studies employing long-term systemic manipulations. Here we show how orexin neurons in freely behaving mice respond in real time to food presentations, and how this response is modulated by differences in metabolic state and salience. Orexin neurons increased activity during approach to food, and this activity declined to baseline at the start of consummatory behavior. Furthermore, the activity of orexin neurons on approach was enhanced by manipulations of metabolic state, and increased food salience. We investigated the nucleus accumbens shell (NAcSh) as a candidate afferent region to inhibit LH orexin neurons following approach, and using projection and cell type-specific electrophysiology, demonstrated that the NAcSh forms both direct and indirect inhibitory projections to LH orexin cells. Together these findings reveal that the activity of orexin neurons is associated with food approach rather than consumption, is modulated by motivationally relevant factors, and that the NAcSh-LH pathway is capable of suppressing orexin cell recruitment.

scholarly journals The DMCdrive: practical 3D-printable micro-drive system for reliable chronic multi-tetrode recording and optogenetic application in freely behaving rodents

2020 ◽  
Author(s):  
Hoseok Kim ◽  
Hans Sperup Brünner ◽  
Marie Carlén
Keyword(s):  
Low Cost ◽  
Network Activity ◽  
Electrophysiological Recording ◽  
Electrophysiological Recordings ◽  
Build Time ◽  
Cell Type Specific ◽  
Freely Behaving ◽  
Freely Moving ◽  
Electrophysiological Methods

AbstractElectrophysiological recording and optogenetic control of neuronal activity in behaving animals have been integral to the elucidation of how neurons and circuits modulate network activity in the encoding and causation of behavior. However, most current electrophysiological methods require substantial economical investments and prior expertise. Further, the inclusion of optogenetics with electrophysiological recordings in freely moving animals remains a general challenge. Expansion of the technological repertoire across laboratories, research institutes, and countries, demands open access to high-quality devices that can be built with little or no prior expertise from easily accessible parts of low cost. We here present a very affordable, truly easy-to-assemble micro-drive for electrophysiology in combination with optogenetics in freely moving mice and rats. The DMCdrive is particularly suited for reliable long-term recordings of neurons and network activities, and simplify optical tagging and manipulation of neurons in the recorded brain region. The highly functional and practical drive design has been optimized for accurate tetrode movement in brain tissue, and remarkably reduced build time. We provide a complete overview of the drive design, its assembly and use, and proof-of-principle demonstration of long-term recordings paired with cell-type-specific optogenetic manipulations in the prefrontal cortex (PFC) of freely moving transgenic mice and rats.

scholarly journals Modern views on the problem of sepsis

2020 ◽  
pp. 18-26
Author(s):  
V.S. Kopcha
Keyword(s):  
Infectious Disease ◽  
Inflammatory Response ◽  
Clinical Case ◽  
Conservative Therapy ◽  
Medical Community ◽  
Etiological Factors ◽  
Systemic Reactions ◽  
Almost All ◽  
Increased Activity

BACKGROUND. By defining the cornerstone of sepsis as the “systemic” of the inflammatory response in the form of cytokine violations, the authors of the corresponding concept are forced to recognize the etiological factors almost all pathogens of infectious diseases, which naturally go with the increased activity of cytokines in serum. Without diminishing the importance of these components of inflammation, one should pay attention to the postulate that not only viruses and protozoa never cause sepsis, but also all non-bacterial pathogens are not etiological factors of this disease, although they lead to severe systemic reactions accompanied by an increase in the level of proinflammatory cytokines. OBJECTIVE. The purpose of the work is to draw the attention of physicians to the discrepancy between the new notions about sepsis imposed on the medical community and accepted not only by anesthetists, resuscitative surgeons and surgeons, but also by many infectionists. MATERIALS AND METHODS. A detailed analysis of the clinical case of sepsis in a young woman is presented, which, due to adequate surgical and long-term conservative therapy, has safely recovered. CONCLUSIONS. Sepsis is a generalized acyclic infectious disease of the bacterial and/or fungal etiology that develops in an immunodeficient organism with characteristic pathomorphological and pathologist changes in organs and tissues.

Device for Pore Solution Extraction from Cement-Based Materials and its Application

2016 ◽  
Vol 680 ◽  
pp. 365-369
Author(s):  
Jian Liang Zhang ◽  
An Qun Lu ◽  
Hua Li ◽  
Rui Wang ◽  
Wen Bin Wang ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Pore Solution ◽  
Early Age ◽  
Cement Pastes ◽  
Cement Based Materials ◽  
Different Ages ◽  
Low Rate ◽  
Relevant Factors

In this paper, a device for pore solution extraction from cement-based materials was presented, The relevant Factors of Efficiency of Pore Solution Extraction and the effects of squeezing pressures on the chemical concentrations of pore solutions were studied. The results shows, the efficiency of pore solution extraction can be effected by pressure values, squeezing duration, pressure maintaining time; A low rate of pressures loading is suitable for early-age cement pastes, and long-term samples can take larger rate; 30 minutes loading time can be adopted for specimens with all the different ages; no significant differences were observed regarding the chemical composition (Na and K) of the pore solution extracted between 300 and 900MPa.

scholarly journals Altering gain of the infralimbic-to-accumbens shell circuit alters economically dissociable decision-making algorithms

2018 ◽  
Vol 115 (27) ◽  
pp. E6347-E6355 ◽  
Author(s):  
Brian M. Sweis ◽  
Erin B. Larson ◽  
A. David Redish ◽  
Mark J. Thomas
Keyword(s):  
Decision Making ◽  
Information Processing ◽  
Synaptic Transmission ◽  
Self Control ◽  
Nucleus Accumbens Shell ◽  
Synaptic Remodeling ◽  
Reward Seeking ◽  
Deliberative Processes ◽  
Reward Valuation

The nucleus accumbens shell (NAcSh) is involved in reward valuation. Excitatory projections from infralimbic cortex (IL) to NAcSh undergo synaptic remodeling in rodent models of addiction and enable the extinction of disadvantageous behaviors. However, how the strength of synaptic transmission of the IL–NAcSh circuit affects decision-making information processing and reward valuation remains unknown, particularly because these processes can conflict within a given trial and particularly given recent data suggesting that decisions arise from separable information-processing algorithms. The approach of many neuromodulation studies is to disrupt information flow during on-going behaviors; however, this limits the interpretation of endogenous encoding of computational processes. Furthermore, many studies are limited by the use of simple behavioral tests of value which are unable to dissociate neurally distinct decision-making algorithms. We optogenetically altered the strength of synaptic transmission between glutamatergic IL–NAcSh projections in mice trained on a neuroeconomic task capable of separating multiple valuation processes. We found that induction of long-term depression in these synapses produced lasting changes in foraging processes without disrupting deliberative processes. Mice displayed inflated reevaluations to stay when deciding whether to abandon continued reward-seeking investments but displayed no changes during initial commitment decisions. We also developed an ensemble-level measure of circuit-specific plasticity that revealed individual differences in foraging valuation tendencies. Our results demonstrate that alterations in projection-specific synaptic strength between the IL and the NAcSh are capable of augmenting self-control economic valuations within a particular decision-making modality and suggest that the valuation mechanisms for these multiple decision-making modalities arise from different circuits.

Neonatal isolation stress alters bidirectional long-term synaptic plasticity in amygdalo-hippocampal synapses in freely behaving adult rats

2008 ◽  
Vol 1193 ◽  
pp. 25-33 ◽  
Author(s):  
J. Harry Blaise ◽  
Jessica L. Koranda ◽  
Urey Chow ◽  
Kaitlin E. Haines ◽  
Emily C. Dorward
Keyword(s):  
Synaptic Plasticity ◽  
Adult Rats ◽  
Isolation Stress ◽  
Hippocampal Synapses ◽  
Freely Behaving

Depression: The predisposing influence of stress

1982 ◽  
Vol 5 (1) ◽  
pp. 89-99 ◽  
Author(s):  
Hymie Anisman ◽  
Robert M. Zacharko
Keyword(s):  
Major Element ◽  
Behavioral Control ◽  
Affective State ◽  
Traumatic Experiences ◽  
Synthetic Enzymes ◽  
Adaptive Processes ◽  
Neurochemical Changes ◽  
Increased Activity ◽  
Behavioral Pathology

AbstractAversive experiences have been thought to provoke or exacerbate clinical depression. The present review provides a brief survey of the stress-depression literature and suggests that the effects of stressful experiences on affective state may be related to depletion of several neurotransmitters, including norepinephrine, dopamine, and serotonin. A major element in determining the neurochemical changes is the organism's ability to cope with the aversive stimuli through behavioral means. Aversive experiences give rise to behavioral attempts to cope with the stressor, coupled with increased utilization and synthesis of brain amines to contend with environmental demands. When behavioral coping is possible, neurochemical systems are not overly taxed, and behavioral pathology will not ensue. However, when there can be no behavioral control over the stressful stimuli, or when the aversive experience is perceived as uncontrollable, increased emphasis is placed on coping through endogenous neurochemical mechanisms. Amine utilization increases appreciably and may exceed synthesis, resulting in a net reduction of amine stores, which in turn promotes or exacerbates affective disorder. The processes governing the depletions may be subject to sensitization or conditioning, such that exposure to traumatic experiences may have long-term repercussions when the organism subsequently encounters related stressful stimuli. With continued uncontrollable stimulation, adaptation occurs in the form of increased activity of synthetic enzymes, and levels of amines approach basal values. It is suggested that either the initial amine depletion provoked by aversive experiences or a dysfunction of the adaptive processes, resulting in persistent amine depletion, contributes to behavioral depression. Aside from the contribution of behavioral coping, several organismic, experiential, and environmental variables will influence the effects of aversive experiences on neurochemical activity, and may thus influence vulnerability to depression.

scholarly journals Splenic primitive hematopoietic stem cell (PHSC) activity is enhanced by steel factor because of PHSC proliferation

Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3146-3151 ◽  
Author(s):  
DE Harrison ◽  
KM Zsebo ◽  
CM Astle
Keyword(s):  
Similar Degree ◽  
Functional Abilities ◽  
Rapid Cycling ◽  
Hematopoietic Stem ◽  
Kit Ligand ◽  
Donor Type ◽  
Factor C ◽  
Increased Activity

Abstract To test whether primitive hematopoietic stem cells (PHSCs) are stimulated by Steel (SI) factor (c-kit ligand) in vivo, donor mice were studied after three or seven daily injections of SI factor. PHSC activity was measured as long-term erythroid and lymphoid competitive repopulating ability. Cells to be tested (usually marrow or spleen cells from treated donors) were mixed with untreated competitor marrow that produces erythrocytes and lymphocytes that are genetically distinguishable from the donors by differences in hemoglobin (Hb) and glucosephosphate isomerase (GPI) markers. These cell mixtures were injected into lethally irradiated hosts, and after 111 to 293 days, functional abilities of donor PHSC populations were assessed and expressed as percentages of donor-type Hb and GPI in the host's circulating erythrocytes and lymphocytes, respectively. A striking increase in splenic PHSC activity occurred after seven daily injections of SI factor, with a much smaller increase after three daily injections. Both three and seven daily injections of SI factor slightly reduced marrow PHSC activity. Rapid cycling greatly increases PHSC vulnerability to 5-fluorouracil (5FU). To test whether SI factor stimulates PHSCs into rapid cycling, donor mice were given a dose of 5FU in addition to SI factor. The increase in splenic PHSCs after 7 days of treatment with SI factor occurred to a similar degree whether donors were or were not treated with 5FU on day 8. However, a dose of 5FU on day 4 of the SI factor treatments almost totally prevented the increase in splenic PHSC activity. Apparently this increased activity requires PHSC cycling throughout the period of SI factor treatment.

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