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1
Abnormal subcortical deep-gray matter susceptibility-weighted imaging filtered phase measurements in patients with multiple sclerosis A case-control study.
2011-07-27

OBJECTIVE: To investigate abnormal phase on susceptibility-weighted imaging (SWI)-filtered phase images indicative of iron content, in subcortical deep-gray matter (SDGM) of multiple sclerosis (MS) patients and healthy controls (HC), and to explore its relationship with MRI outcomes. METHODS: 169 relapsing-remitting (RR) and 64 secondary-progressive (SP) MS patients, and 126 ...

PubMed

2
SYSTEMIC AND INTRA-ACCUMBENS ADMINISTRATION OF AMPHETAMINE DIFFERENTIALLY AFFECTS CORTICAL ACETYLCHOLINE RELEASE

SYSTEMIC AND INTRA-ACCUMBENS ADMINISTRATION OF AMPHETAMINE DIFFERENTIALLY AFFECTS CORTICAL experiments tested the hypothesis that the amphetamine-induced increase in dopamine release in the nucleus amphetamine to stimulate cortical acetylcholine release. The effects of systemic or intra

E-print Network

3
Intra-Accumbens Amphetamine Increases the Conditioned Incentive Salience of Sucrose Reward: Enhancement of Reward "Wanting"

Intra-Accumbens Amphetamine Increases the Conditioned Incentive Salience of Sucrose Reward. Berridge Department of Psychology, University of Michigan, Ann Arbor, Michigan 48109 Amphetamine bilateral micro- injection of intra-accumbens vehicle or amphetamine (0.0, 2.0, 10.0, or 20.0 g/0.5 l

E-print Network

4
Hippocampus, amygdala, and stress: interacting systems that affect susceptibility to addiction.
2011-01-01

Stress is one of the major factors in drug abuse, particularly in relapse and drug-seeking behavior. However, the mechanisms underlying the interactions between stress and drug abuse are unclear. For many years, studies have focused on the role of the dopaminergic reward system in drug abuse. Our results, for example, show that increased dopaminergic activity is induced by ...

PubMed

5
Hippocampus, amygdala and stress: Interacting systems that affect susceptibility to addiction
2011-01-01

Stressis one of the major factors in drug abuse, particularly in relapse and drug-seeking behavior. However, the mechanisms underlying the interactions between stress and drug abuse are unclear. For many years, studies have focused on the role of the dopaminergic reward system in drug abuse. Our results show that an increased dopaminergic activity is induced by drug ...

PubMed Central

6
A novel role of the WNT-dishevelled-GSK3? signaling cascade in the mouse nucleus accumbens in a social defeat model of depression.
2011-06-22

Based on earlier gene expression and chromatin array data, we identified the protein, dishevelled (DVL)-2, as being regulated in the nucleus accumbens (NAc), a key brain reward region, in the mouse social defeat model of depression. Here, we validate these findings by showing that DVL2 mRNA and protein levels are downregulated in NAc of mice susceptible to ...

PubMed

7
Implication of Rho-associated kinase in the elevation of extracellular dopamine levels and its related behaviors induced by methamphetamine in rats.
2003-07-01

A growing body of evidence suggests that several protein kinases are involved in the expression of pharmacological actions induced by a psychostimulant methamphetamine. The present study was designed to investigate the role of the Rho/Rho-associated kinase (ROCK)-dependent pathway in the expression of the increase in extracellular levels of dopamine in the nucleus ...

PubMed

8
Effects of propofol and fentanyl on extracellular levels of gamma-aminobutyric acid in the rat nucleus accumbens: an in vivo microdialysis study.
1998-12-01

The effects of propofol, a hydrophobic intravenous anaesthetic, and fentanyl, an opiate analgesic, on extracellular concentrations of gamma-aminobutyric acid (GABA) in the nucleus accumbens of rats were studied using in vivo brain microdialysis. The concentrations of GABA in the microdialysate of the nucleus accumbens reached a stable baseline value ...

PubMed

9
N-methyl-D-aspartic acid biphasically regulates the biochemical and electrophysiological response of A10 dopamine neurons in the ventral tegmental area: in vivo microdialysis and in vitro electrophysiological studies.
1994-12-15

The effects of local perfusion of the ventral tegmental area (VTA) with N-methyl-D-aspartic acid (NMDA) on extracellular dopamine concentrations in the nucleus accumbens were investigated by using in vivo microdialysis in halothane anaesthetized rats. The electrophysiological response of VTA dopamine neurons to NMDA were also assessed in an in vitro rat brain slice ...

PubMed

10
Cocaine and Amphetamine Increase Extracellular Dopamine in the Nucleus Accumbens of Mice Lacking

Cocaine and Amphetamine Increase Extracellular Dopamine in the Nucleus Accumbens of Mice Lacking dopamine in the dorsal striatum. Here we report that, in DAT-KO mice, cocaine and amphetamine increase; cocaine; amphetamine; reboxetine Cocaine and amphetamine psychostimulants are abused by hu- mans (Johanson

E-print Network

11
Increased glutamate release into the intercellular space of the nucleus accumbens (N. accumbens) during substitution of food reinforcement with aversive or neutral stimuli.
2004-02-01

Experiments on Sprague-Dawley rats using vital intracerebral dialysis and HPLC with electrochemical detection demonstrated that presentation of the animals with inedible imitation food or food containing a bitter flavor instead of the expected food reinforcement led to rapid increases in glutamate levels in the intercellular space of the nucleus accumbens. ...

PubMed

12
[Changes in glutamate release in the rat nucleus accumbens during food and pain reinforcement].

In vivo microdialysis combined with HPLC-EC analysis was used to monitor extracellular glutamate in the n. accumbens of Sprague-Dawley rats during footshock and food delivery. The footshock presentation resulted in a delayed increase in extracellular glutamate level, whereas the food intake caused its decrease. The intra-accumbens ...

PubMed

13
Chronic cocaine increases neurotensin gene expression in the shell of the nucleus accumbens and in discrete

Chronic cocaine increases neurotensin gene expression in the shell of the nucleus accumbens. Abstract The effects of chronic cocaine administration on neurotensin (NT) mRNA expression were investigated in the rat brain using in situ hybridization. Adult Wistar rats were injected daily with cocaine

E-print Network

14
Effects of acute and chronic clozapine on dopamine release and metabolism in the striatum and nucleus accumbens of conscious rats.
1990-08-01

1. The effect of single and repeated (once daily for 23 days) oral doses of 20 and 60 mg kg-1 clozapine on dopamine release and metabolism were studied by intracerebral dialysis in the striatum and nucleus accumbens of conscious rats. 2. The basal output of dopamine, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum and nucleus ...

PubMed Central

15
A role for repressive histone methylation in cocaine-induced vulnerability to stress.
2011-08-25

Substance abuse increases an individual's vulnerability to stress-related illnesses, which is presumably mediated by drug-induced neural adaptations that alter subsequent responses to stress. Here, we identify repressive histone methylation in nucleus accumbens (NAc), an important brain reward region, as a key mechanism linking cocaine exposure to ...

PubMed

16
The flexible approach hypothesis: unification of effort and cue-responding hypotheses for the role of nucleus accumbens dopamine in the activation of reward-seeking behavior.
2010-12-01

Dopamine released in the nucleus accumbens is thought to contribute to the decision to exert effort to seek reward. This hypothesis is supported by findings that performance of tasks requiring higher levels of effort is more susceptible to disruption by manipulations that reduce accumbens dopamine function than tasks that require less ...

PubMed

17
The flexible approach hypothesis: Unification of effort and cue responding hypotheses for the role of nucleus accumbens dopamine in the activation of reward-seeking behavior
2010-12-08

Dopamine released in the nucleus accumbens is thought to contribute to the decision to exert effort to seek reward. This hypothesis is supported by findings that performance of tasks requiring higher levels of effort is more susceptible to disruption by manipulations that reduce accumbens dopamine function than tasks that require less ...

PubMed Central

18
Behavioral sensitization to cocaine is associated with increased glutamate receptor trafficking to the postsynaptic density after extended withdrawal period.
2008-11-01

Glutamatergic signaling plays an important role in the behavioral and molecular plasticity observed in behavioral sensitization to cocaine. Redistribution of the glutamate receptors in the synaptosomal membrane fraction was investigated in the nucleus accumbens, dorsolateral striatum, and ventral tegmental area at 1 or 21 days of withdrawal in behaviorally sensitized rats. At ...

PubMed

19
The High-Frequency Susceptibility of Certain ...
1970-10-01

... rate and the susceptibility after long ... and increase the susceptibilities to quasi ... Descriptors : (*FERRITES, MAGNETIC PROPERTIES), MAGNETIC ...

DTIC Science & Technology

20
Relationship between Age and Susceptibility to ...
1995-07-01

... Title : Relationship between Age and Susceptibility to Decompression Sickness. ... They also show that susceptibility to DCS increases with age. ...

DTIC Science & Technology

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21
Linking nucleus accumbens dopamine and blood oxygenation

REVIEW Linking nucleus accumbens dopamine and blood oxygenation Brian Knutson & Sasha E. B. Gibbs-Verlag 2007 Abstract Rationale Animal research suggests that anticipation of reward can elicit dopamine in the NAcc. However, the physiolog- ical relationship between dopamine release and BOLD signal increases

E-print Network

22
Effect of experimenter-delivered and self-administered cocaine on extracellular beta-endorphin levels in the nucleus accumbens.
2003-03-01

Beta-endorphin is an endogenous opioid peptide that has been hypothesized to be involved in the behavioral effects of drugs of abuse including psychostimulants. Using microdialysis, we studied the effect of cocaine on extracellular levels of beta-endorphin in the nucleus accumbens, a brain region involved in the reinforcing effects of psychostimulant drugs. ...

PubMed

23
Brain Research 894 (2001) 354�358 www.elsevier.com/locate/bres

between the effects of intra-accumbens administration of amphetamine and exposure to a novel environment Previous research has demonstrated an interaction between the effects of amphetamine and exposure, the administration of intra-accumbens amphetamine was hypothesized to potentiate the increase in cortical

E-print Network

24
Impulsivity as a mediating mechanism between early-life adversity and addiction: Theoretical comment on Lovic et al. (2011).
2011-08-01

Early-life adversity, impulsivity, and dopaminergic function have all been implicated in adult drug addiction. The article by Lovic, Keen, Fletcher, and Fleming in this issue further elucidates this relationship by demonstrating that early-life adversity can increase impulsivity and decrease behavioral flexibility in adulthood. Recent literature suggests that these results are ...

PubMed

25
Galanin and addiction.
2010-01-01

There has been increasing interest in the ability of neuropeptides involved in feeding to modulate circuits important for responses to drugs of abuse. A number of peptides with effects on hypothalamic function also modulate the mesolimbic dopamine system (ventral tegmental area and nucleus accumbens). Similarly, common stress-related pathways can modulate ...

PubMed

26
Galanin and addiction.
2008-06-01

There has been increasing interest in the ability of neuropeptides involved in feeding to modulate circuits important for responses to drugs of abuse. A number of peptides with effects on hypothalamic function also modulate the mesolimbic dopamine system (ventral tegmental area and nucleus accumbens). Similarly, common stress-related pathways can modulate ...

PubMed

27
Phosphorylation-dependent trafficking of GluR2-containing AMPA receptors in the nucleus accumbens plays a critical role in the reinstatement of cocaine seeking
2008-10-22

A growing body of evidence indicates that enhanced AMPA-mediated glutamate transmission in the core of the nucleus accumbens is critically involved in cocaine priming-induced reinstatement of drug seeking, an animal model of relapse. However, the extent to which increased glutamate transmission in the other major subregion of the nucleus ...

PubMed Central

28
Repeated morphine exposure decreased the nucleus accumbens excitability during short-term withdrawal.
2008-10-01

It is well known that the nucleus accumbens plays an important role in drug reinforcing effect and relapse. However, the cellular neuroadaptations that take place in accumbens neurons after repeated drug exposure are still not well understood, especially for opioids. Here, we examined how nucleus accumbens neuronal excitability becomes ...

PubMed

29
Slow phasic changes in nucleus accumbens dopamine release during fixed ratio acquisition: a microdialysis study.
2011-08-25

Nucleus accumbens dopamine (DA) is a critical component of the brain circuitry regulating behavioral output during reinforcement-seeking behavior. Several studies have investigated the characteristics of accumbens DA release during the performance of well-learned operant behaviors, but relatively few have focused on the initial acquisition of particular ...

PubMed

30
Mesolimbic effects of the antidepressant fluoxetine in Holtzman rats, a genetic strain with increased vulnerability to stress.
2011-03-02

This is the first metabolic mapping study of the effects of fluoxetine after learned helplessness training. Antidepressants are the most commonly prescribed medications, but the regions underlying treatment effects in affectively disordered brains are poorly understood. We hypothesized the antidepressant action of fluoxetine would produce adaptations in mesolimbic regions after 2 weeks of ...

PubMed

31
[Comparison in changes of glutamate level in the rat nucleus accumbens induced by D1- and D2-dopamine receptors during feeding].
2002-01-01

The influence of dopamine D1- and D2-like receptors blockage on glutamate level in the n. accumbens of Sprague-Dawly rats during feeding was investigated by in vivo microdialysis combined with HPLC-EC analysis. Food intake resulted in a decrease in extracellular glutamate level. Infusion of D1-like dopamine receptor-blocker (SCH-23390, 0.01 mM) into the n. ...

PubMed

32
Good Vibrations: Cross-Frequency Coupling in the Human Nucleus Accumbens during Reward Processing
2009-05-01

The nucleus accumbens is critical for reward-guided learning and decision-making. It is thought to "gate" the flow of a diverse range of information (e.g., rewarding, aversive, and novel events) from limbic afferents to basal ganglia outputs. Gating and information encoding may be achieved via cross-frequency coupling, in which bursts of high-frequency activity occur ...

ERIC Educational Resources Information Center

33
Apathy is associated with volume of the nucleus accumbens in patients infected with HIV.
2005-01-01

Apathy refers to a reduction in self-initiated behavior, and it is commonly reported by patients infected with human immunodeficiency virus (HIV). It remains unclear whether apathy among HIV patients reflects a direct effect of the virus on subcortical brain circuits or a secondary neuropsychiatric symptom. In the present study we examined the relationship between ratings of apathy and ...

PubMed

34
Apathy is Associated With Volume of the Nucleus Accumbens in Patients Infected With HIV
2005-01-01

Apathy refers to a reduction in self-initiated behavior, and it is commonly reported by patients infected with human immunodeficiency virus (HIV). It remains unclear whether apathy among HIV patients reflects a direct effect of the virus on subcortical brain circuits or a secondary neuropsychiatric symptom. In the present study we examined the relationship between ratings of apathy and ...

PubMed Central

35
Muscarinic acetylcholine receptors in the nucleus accumbens core and shell contribute to cocaine priming-induced reinstatement of drug seeking.
2010-10-27

Muscarinic acetylcholine receptors in the nucleus accumbens play an important role in mediating the reinforcing effects of cocaine. However, there is a paucity of data regarding the role of accumbal muscarinic acetylcholine receptors in the reinstatement of cocaine-seeking behavior. The goal of these experiments was to assess the role of muscarinic acetylcholine receptors in ...

PubMed

36
Calcium-binding protein distributions and fiber connections of the nucleus accumbens in the pigeon (Columba livia).
2011-05-01

Until recently, the exact location of the avian nucleus accumbens within the basal forebrain had not been well established (Reiner et al. [2004] J Comp Neurol 473:377-414). While a number of previous studies have shown afferents and efferents of the presumptive "nucleus accumbens," detailed and accurate connection patterns of this newly recognized area are ...

PubMed

37
Nucleus accumbens NMDA receptor subunit expression and function is enhanced in morphine-dependent rats.
2007-01-30

We have previously shown, using radioligand binding studies, that N-methyl-d-aspartate (NMDA) NR1 and NR2A receptor subunits density was decreased in the forebrain of morphine-dependent rats. We have now determined if morphine-dependent rats display regional differences in NMDA receptor expression and whether such changes are functionally relevant. In morphine-dependent rats, the expression of NR1 ...

PubMed

38
Nicotine stimulation of extracellular glutamate levels in the nucleus accumbens: neuropharmacological characterization.
2000-02-01

In the present study, we have characterized the neuropharmacological regulation of nicotine-induced increases in extracellular nucleus accumbens glutamate levels. Sprague-Dawley rats were stereotaxically implanted with 2 mm microdialysis probes in the nucleus accumbens and on the following day in vivo microdialysis experiments were ...

PubMed

39
The persistence of behavioral sensitization to cocaine parallels enhanced inhibition of nucleus accumbens neurons
1995-01-01

The mesoaccumbens dopamine system is intricately in-volved in the locomotor stimulation produced by cocaine and sensitization of this effect following repeated cocaine administration. The mechanisms responsible for the ex-pression of sensitized locomotion appear to involve alter-ations in both presynaptic (increased dopamine release) and postsynaptic ...

E-print Network

40
The pharmacology of mesolimbic dopamine neurons: a dual-probe microdialysis study in the ventral tegmental area and nucleus accumbens of the rat brain.
1996-04-15

Receptor-specific compounds were applied by retrograde microdialysis to the ventral tegmental area (VTA) of the rat brain. The effect of the intrategmental infusions on extracellular dopamine in the ipsilateral nucleus accumbens were recorded with a second microdialysis probe. Intrategmental infusion of muscimol (10-40 microM) or baclofen (50 microM) decreased extracellular ...

PubMed

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41
Acute Administration of Clozapine and Risperidone Altered Dopamine Metabolism More in Rat Caudate than in Nucleus Accumbens: A Dose-Response Relationship
2010-06-30

The present study compares the extrapyramidal and neurochemical effects of clozapine and risperidone in rat caudate (corpus striatum) and nucleus accumbens (ventral striatum) dose-dependently. Animals injected with clozapine (2.5, 5.0 and 10.0 mg/kg IP) or risperidone (1.0, 2.5 and 5.0 mg/kg IP) in acute were sacrificed 1 h later to collect brain samples. Extrapyramidal side ...

PubMed Central

42
Differential effects produced by ketamine on oscillatory activity recorded in the rat hippocampus, dorsal striatum and nucleus accumbens.
2010-04-22

Previously, we showed that NMDA antagonists enhance high-frequency oscillations (130-180?Hz) in the nucleus accumbens. However, whether NMDA antagonists can enhance high-frequency oscillations in other brain regions remains unclear. Here, we used monopolar, bipolar and inverse current source density techniques to examine oscillatory activity in the hippocampus, a region known ...

PubMed

43
Air pollution increases forest susceptibility to wildfires in southern California

Many factors increase susceptibility of forests to wildfire in California. Among them are increases in human population, changes in land use, increased fire ... ...

NBII National Biological Information Infrastructure

44
[Enhancement of glutamate release in the extracellular space of nucleus accumbens during presentation of aversive or neutral stimuli instead of food reinforcement].

By means of in vivo microdialysis combined with HPLC/EC analysis it was shown that presentation to a rat of an inedible object (a piece of rubber) or an aversive object (food of bitter taste) instead of expected food caused a marked increase in extracellular glutamate level in n. accumbens. In rats not expecting food reinforcement, extracellular glutamate ...

PubMed

45
Drug-Induced Plasticity Contributing to Heightened Relapse Susceptibility: Neurochemical Changes & Augmented Reinstatement in High-Intake Rats
2010-01-06

A key in understanding the neurobiology of addiction and developing effective pharmacotherapies is revealing drug-induced plasticity that results in heightened relapse susceptibility. Previous studies have demonstrated that increased extracellular glutamate, but not dopamine, in the nucleus accumbens core (NAcc) is necessary for ...

PubMed Central

46
Endogenous GDNF in ventral tegmental area and nucleus accumbens does not play a role in the incubation of heroin craving.
2010-12-23

Glial cell line-derived neurotrophic factor (GDNF) activity in ventral tegmental area (VTA) mediates the time-dependent increases in cue-induced cocaine-seeking after withdrawal (incubation of cocaine craving). Here, we studied the generality of these findings to incubation of heroin craving. Rats were trained to self-administer heroin for 10 days (6 hours/day; 0.075 ...

PubMed

47
Inhibition of PKMzeta in nucleus accumbens core abolishes long-term drug reward memory.
2011-04-01

During abstinence, memories of drug-associated cues persist for many months, and exposure to these cues often provokes relapse to drug use. The mechanisms underlying the maintenance of these memories are unknown. A constitutively active atypical protein kinase C (PKC) isozyme, protein kinase M ? (PKM?), is required for maintenance of spatial memory, conditioned taste aversion, and other memory ...

PubMed

48
Inhibition of PKM? in Nucleus Accumbens Core Abolishes Long-Term Drug Reward Memory
2011-04-06

During abstinence, memories of drug-associated cues persist for many months, and exposure to these cues often provokes relapse to drug use. The mechanisms underlying the maintenance of these memories are unknown. A constitutively active atypical protein kinase C (PKC) isozyme, protein kinase M ? (PKM?), is required for maintenance of spatial memory, conditioned taste aversion, and other memory ...

PubMed Central

49
Agmatine modulates neuroadaptations of glutamate transmission in the nucleus accumbens of repeated morphine-treated rats.
2010-10-13

It has been proved that agmatine inhibits opioid dependence, yet the neural mechanism remains unclear. In the present study, the effect of agmatine on the neuroadaptation of glutamate neurotransmission induced by morphine dependence, including changes of the extracellular glutamate level and glutamate receptors in the nucleus accumbens was investigated. We found that agmatine ...

PubMed

50
Fentanyl increases dopamine release in rat nucleus accumbens: involvement of mesolimbic mu- and delta-2-opioid receptors.
1999-01-01

The effects of the mu-receptor agonist fentanyl on extracellular levels of dopamine in rat nucleus accumbens were studied in awake animals by in vivo brain microdialysis. Fentanyl dose-dependently increased the levels of dopamine when given intravenously (microg/kg) or via a microdialysis probe placed into the ventral tegmental area or the nucleus ...

PubMed

51
Physician Survey on Cancer Susceptibility Testing

PHYSICIAN SURVEY ON CANCER SUSCEPTIBILITY TESTING Genetic tests for inherited cancer susceptibility are DNA tests for inherited genetic mutations that are associated with an increased risk of cancer.

Cancer.gov

52
Increased brain dopamine and dopamine receptors in schizophrenia
1982-09-01

In postmortem samples of caudate nucleus and nucleus accumbens from 48 schizophrenic patients, there were significant increases in both the maximum number of binding sites (Bmax) and the apparent dissociation constant (KD) for tritiated spiperone. The increase in apparent KD probably reflects the presence of residual neuroleptic drugs, ...

Energy Citations Database

53
Stimulation of the nucleus accumbens as behavioral reward in awake behaving monkeys.
2011-06-13

It has been known that monkeys will repeatedly press a bar for electrical stimulation in several different brain structures. We explored the possibility of using electrical stimulation in one such structure, the nucleus accumbens, as a substitute for liquid reward in animals performing a complex task, namely visual search. The animals had full access to water in the cage at ...

PubMed

54
Effects of bupropion on the forced swim test and release of dopamine in the nucleus accumbens in ACTH-treated rats.
2010-06-06

The dopamine reuptake inhibitor bupropion has clinically been proven to improve depression and treatment-resistant depression. We examined its influence on the duration of immobility during the forced swim test in adrenocorticotropic hormone (ACTH)-treated rats and further analyzed the possible role of dopamine receptors in this effect. Additionally, the mechanism by which bupropion acts in this ...

PubMed

55
Conditioned taste aversion from neostigmine or methyl-naloxonium in the nucleus accumbens.
2011-05-01

An opioid antagonist injected in the nucleus accumbens of a morphine-dependent rat will lower extracellular dopamine and release acetylcholine (ACh), as also seen in opiate withdrawal. It was hypothesized that raising extracellular ACh experimentally would be aversive as reflected by the induction of a conditioned taste aversion. Rats were implanted with cannulas aimed above ...

PubMed

56
Feeding-induced decrease in extracellular glutamate level in the rat nucleus accumbens: dependence on glutamate uptake.
2002-01-01

In vivo microdialysis combined with high-performance liquid chromatography and electrochemical detection was used to monitor extracellular glutamate levels in the medial nucleus accumbens of Sprague-Dawley rats during their feeding behaviour. Consumption of a palatable new diet or a diet to which rats were previously exposed caused a decrease in extracellular level of ...

PubMed

57
Expression of amphetamine sensitization is associated with recruitment of a reactive neuronal population in the nucleus accumbens core
2008-03-18

RationaleRepeated exposure to psychostimulant drugs causes a long-lasting increase in the psychomotor and reinforcing effects of these drugs and an array of neuroadaptations. One such alteration is a hypersensitivity of striatal activity such that a low dose of amphetamine in sensitized animals produces dorsal striatal activation patterns similar to acute treatment with a high ...

PubMed Central

58
Clonidine reduces dopamine and increases GABA in the nucleus accumbens: an in vivo microdialysis study.
1998-07-01

The effects of clonidine, an alpha2 adrenoceptor agonist, on extracellular concentrations of dopamine and gamma-aminobutyric acid (GABA) in the nucleus accumbens of rats were studied by using in vivo brain microdialysis. Clonidine (5 microg/kg i.v.) significantly decreased the brain microdialysate concentration of dopamine in the nucleus accumbens up to a ...

PubMed

59
N-methyl-d-aspartic acid receptors are altered by stress and alcohol in Wistar-Kyoto rat brain.
2010-05-11

Previous studies have shown that the Wistar-Kyoto (WKY) rat strain is more sensitive to stressors and consumes significant quantities of alcohol under basal as well as stressful conditions when compared to other strains. Given that the glutamate neurotransmitter system has been implicated in depression and addiction, the goals of the present study were to investigate the effects of stress and ...

PubMed

60
Differential tonic influence of lateral habenula on prefrontal cortex and nucleus accumbens dopamine release
2008-04-01

Conditions of increased cognitive or emotional demand activate dopamine release in a regionally selective manner. Whereas the brief millisecond response of dopamine neurons to salient stimuli suggests that dopamine�s influence on behaviour may be limited to signalling certain cues, the prolonged availability of dopamine in regions such as the prefrontal cortex and nucleus ...

PubMed Central

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61
Spatially selective reward site responses in tonically active neurons of the nucleus accumbens in behaving rats.
2005-01-15

To study how hippocampal output signals conveying spatial and other contextual information might be integrated in the nucleus accumbens, tonically active accumbens neurons were recorded in three unrestrained rats as they performed spatial orientation tasks on an elevated round rotatable platform with four identical reward boxes symmetrically placed around ...

PubMed

62
Shell/core differences in mu- and delta-opioid receptor modulation of dopamine efflux in nucleus accumbens.
2008-05-22

The mu- and delta-opioid receptors located at the terminal level in nucleus accumbens are involved in the opiate modulation of dopamine release in this brain area. However, recent studies suggest that the effects of opioid drugs on the core subregion of nucleus accumbens may completely differ from those observed in the shell. We used in vivo microdialysis ...

PubMed

63
Lever pressing responses under a fixed-ratio schedule of mice with 6-hydroxydopamine-induced dopamine depletion in the nucleus accumbens.
2010-10-11

In order to investigate the relationship between dopamine transmission in the nucleus accumbens and operant behavior in mice, mice with 6-hydroxydopamine (6-OHDA)-induced dopamine depletion in the nucleus accumbens were tested for their performance in lever pressing tasks under FR schedules with 8 ratios from FR5 to FR120. The mice were given one 20-mg ...

PubMed

64
Dopamine, Behavioral Economics, and Effort
2009-09-07

There are numerous problems with the hypothesis that brain dopamine (DA) systems, particularly in the nucleus accumbens, directly mediate the rewarding or primary motivational characteristics of natural stimuli such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on ...

PubMed Central

65
Characterization of the oxytocin system regulating affiliative behavior in female prairie voles.
2009-05-29

Oxytocin regulates partner preference formation and alloparental behavior in the socially monogamous prairie vole (Microtus ochrogaster) by activating oxytocin receptors in the nucleus accumbens of females. Mating facilitates partner preference formation, and oxytocin-immunoreactive fibers in the nucleus accumbens have been described in prairie voles. ...

PubMed

66
Characterization of the Oxytocin System Regulating Affiliative Behavior in Female Prairie Voles
2009-05-29

Oxytocin regulates partner preference formation and alloparental behavior in the socially monogamous prairie vole (Microtus ochrogaster) by activating oxytocin receptors in the nucleus accumbens of females. Mating facilitates partner preference formation, and oxytocin-immunoreactive fibers in the nucleus accumbens have been described in prairie voles. ...

PubMed Central

67
Impulsivity Characterization in the Roman High- and Low-Avoidance Rat Strains: Behavioral and Neurochemical Differences
2010-04-20

The selective breeding of Roman high- (RHA) and low-avoidance (RLA) rats for rapid vs extremely poor acquisition of active avoidance behavior in a shuttle-box has generated two phenotypes with different emotional and motivational profiles. The phenotypic traits of the Roman rat lines/strains (outbred or inbred, respectively) include differences in sensation/novelty seeking, anxiety/fearfulness, ...

PubMed Central

68
In vivo dopamine measurements in the nucleus accumbens after nonanesthetic and anesthetic doses of propofol in rats.
2002-10-01

There is growing evidence that propofol acts on affective and reward processes. We designed this study to assess the effect of propofol on the concentration of dopamine in the nucleus accumbens, a main component of the mesolimbic system. The concentration of dopamine in the nucleus accumbens was assessed by using in vivo brain microdialysis in freely ...

PubMed

69
?-opioid receptors are implicated in the increased potency of intra-accumbens nalmefene in ethanol-dependent rats.
2011-02-19

Previously, it was shown that ethanol-dependent animals display increased sensitivity to the general opioid receptor antagonist nalmefene compared to naltrexone. It was hypothesized that the dissociable effects of the two antagonists were attributable to a ?-opioid receptor mechanism. Nucleus accumbens dynorphin is upregulated following chronic ethanol ...

PubMed

70
Inhibitory effect of 4-phenyltetrahydroisoquinoline on locomotion and dopamine release induced by micro-injection of methamphetamine into the nucleus accumbens of the rat.
1993-08-01

The inhibitory effects of 4-phenyl-1,2,3,4-tetrahydroisoquinoline (4-PTIQ) on methamphetamine-induced increases in dopamine and locomotion were investigated. Methamphetamine hydrochloride (10 micrograms) microinjected into the nucleus accumbens increased both locomotor activity and extracellular dopamine levels, measured by the brain ...

PubMed

71
Initial susceptibility of interacting fine particles
1999-05-01

Model calculations of the initial susceptibility of interacting fine particles are presented. It is found that the interactions dramatically reduce the initial susceptibility and increase the temperature peak in the susceptibility/temperature plot. In addition, our initial results indicate that interactions can ...

NASA Astrophysics Data System (ADS)

72
Effect of Elevated Atmospheric Pressure on Antibiotic Susceptibility of Staphylococcus Aureus and Streptococcus Pyogenes.
1972-01-01

Staphylococcus aureus showed decreased susceptibility to penicillin, vancomycin, sodium cephalothin and tetracycline, but increased susceptibility to sodium colistimethate, at a pressure of 68 atm in helium or helium-oxygen gas. Susceptibility of streptoc...

National Technical Information Service (NTIS)

73
Increased Susceptibility of 13Ni-15Co-10Mo Maraging Steel ...
1984-06-01

... Title : Increased Susceptibility of 13Ni-15Co-10Mo Maraging Steel to Hydrogen Embrittlement by Aging at Lower Temperatures,. Corporate Author : ...

DTIC Science & Technology

74
Dietary Stress Increases the Susceptibility of Tribolium castaneum to Beauveria bassiana

... 1603/EC09311 Dietary Stress Increases the Susceptibility of Tribolium castaneum to Beauveria bassiana Jeffrey C. Lord1USDA-ARS, ...

NBII National Biological Information Infrastructure

75
Air pollution increases forest susceptibility to wildfires: a case study ...

Sep 1, 2011 ... Title: Air pollution increases forest susceptibility to wildfires: a case study for the San Bernardino Mountains in southern California ...

Treesearch

76
Air pollution increases forest susceptibility to wildfires: A case study ...

Sep 1, 2011 ... Title: Air pollution increases forest susceptibility to wildfires: A case study in the San Bernardino Mountains in southern California ...

Treesearch

77
Individual differences in dopamine efflux in nucleus accumbens shell and core during instrumental learning
2006-03-01

Combined activation of dopamine D1- and NMDA-glutamate receptors in the nucleus accumbens has been strongly implicated in instrumental learning, the process in which an individual learns that a specific action has a wanted outcome. To assess dopaminergic activity, we presented rats with two sessions (30 trials each) of a one-lever appetitive instrumental task and ...

PubMed Central

78
ANTIDEPRESSANT ACTIONS OF HDAC INHIBITORS
2009-09-16

Persistent symptoms of depression suggest the involvement of stable molecular adaptations in brain, which may be reflected at the level of chromatin remodeling. We find that chronic social defeat stress in mice causes a transient decrease, followed by a persistent increase, in levels of acetylated histone H3 in the nucleus accumbens, an important limbic ...

PubMed Central

79
Nucleus accumbens and effort-related functions: behavioral and neural markers of the interactions between adenosine A2A and dopamine D2 receptors.
2010-01-20

Nucleus accumbens dopamine (DA) is a critical component of the brain circuitry regulating work output in reinforcement-seeking behavior and effort-related choice behavior. Moreover, there is evidence of an interaction between DA D(2) and adenosine A(2A) receptor function. Systemic administration of adenosine A(2A) antagonists reverses the effects of D(2) antagonists on tasks ...

PubMed

80
Extracellular matrix plasticity and GABAergic inhibition of prefrontal cortex pyramidal cells facilitates relapse to heroin seeking.
2010-06-30

Successful treatment of drug addiction is hampered by high relapse rates during periods of abstinence. Neuroadaptation in the medial prefrontal cortex (mPFC) is thought to have a crucial role in vulnerability to relapse to drug seeking, but the molecular and cellular mechanisms remain largely unknown. To identify protein changes that contribute to relapse susceptibility, we ...

PubMed

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81
Extracellular Matrix Plasticity and GABAergic Inhibition of Prefrontal Cortex Pyramidal Cells Facilitates Relapse to Heroin Seeking
2010-09-30

Successful treatment of drug addiction is hampered by high relapse rates during periods of abstinence. Neuroadaptation in the medial prefrontal cortex (mPFC) is thought to have a crucial role in vulnerability to relapse to drug seeking, but the molecular and cellular mechanisms remain largely unknown. To identify protein changes that contribute to relapse susceptibility, we ...

PubMed Central

82
Ethanol-induced locomotor sensitization in DBA/2J mice is associated with alterations in GABA(A) subunit gene expression and behavioral sensitivity to GABA(A) acting drugs.
2010-02-26

Repeated exposure to ethanol may produce increased sensitivity to its acute locomotor stimulant actions, a process referred to as locomotor sensitization. Neuroadaptation within certain brain circuits, including those possessing GABA(A) receptors, may underlie locomotor sensitization to ethanol. Indeed, GABA(A) receptors are documented mediators of ethanol's cellular and ...

PubMed

83
An approach for serotonin depletion in pigs: effects on serotonin receptor binding.
2011-02-01

Depletion of central serotonin (5-HT) levels and dysfunction in serotonergic transmission are implicated in a variety of human CNS disorders. The mechanisms behind these serotonergic deficits have been widely studied using rodent models, but only to a limited extent in larger animal models. The pig is increasingly used as an experimental animal model especially in neuroscience ...

PubMed

84
[Glutamate release in the nucleus accumbens during competitive presentation of aversive and appetitive stimuli].

By means of in vivo microdialysis combined with HPLC analysis, we have shown that extracellular glutamate level in the rat n. accumbens increases during a simultaneous presentation of a palatable diet and a tone previously paired with a footshock, the magnitude of the extracellular glutamate increase being proportional to the latency ...

PubMed

85
The Bivalent Side of the Nucleus Accumbens
2008-10-11

An increasing body of evidence suggests that the nucleus accumbens (NAcc) is engaged in both incentive reward processes and in adaptive responses to conditioned and unconditioned aversive stimuli. Yet, it has been argued that NAcc activation to aversive stimuli may be a consequence of the rewarding effects of their termination, i.e., relief. To address ...

PubMed Central

86
Modafinil enhances extracellular levels of dopamine in the nucleus accumbens and increases wakefulness in rats.
2006-11-13

Modafinil (MOD) is a wakefulness-promoting drug that improves the alertness levels in narcolepsy; however, the molecular mechanism of action remains to be elucidated. We found that after a single icv injection of MOD (10 microg/5 microl) the extracellular levels of dopamine (DA) and l-DOPA collected from the nucleus accumbens were increased and decreased, ...

PubMed

87
Glutamate Transmission in the Nucleus Accumbens Mediates Relapse in Cocaine Addiction

Glutamate Transmission in the Nucleus Accumbens Mediates Relapse in Cocaine Addiction Jennifer L Carolina, Charleston, South Carolina 29425 Elevated dopamine transmission in the nucleus accumbens in the nucleus accumbens, is a primary mediator of cocaine- induced reinstatement of drug-seeking behavior

E-print Network

88
Deltorphin II enhances extracellular levels of dopamine in the nucleus accumbens via opioid receptor-independent mechanisms.
2004-04-26

The effects of the delta2-opioid receptor agonist, deltorphin II, on extracellular levels of dopamine in the rat nucleus accumbens were investigated in awake animals by in vivo brain microdialysis. In agreement with previous studies, perfusion of deltorphin II (50.0 nmol) into the nucleus accumbens significantly increased the ...

PubMed

89
Deficits of mesolimbic dopamine neurotransmission in rat dietary obesity.
2009-02-11

Increased caloric intake in dietary obesity could be driven by central mechanisms that regulate reward-seeking behavior. The mesolimbic dopamine system, and the nucleus accumbens in particular, underlies both food and drug reward. We investigated whether rat dietary obesity is linked to changes in dopaminergic neurotransmission in that region. ...

PubMed

90
DEFICITS OF MESOLIMBIC DOPAMINE NEUROTRANSMISSION IN RAT DIETARY OBESITY
2009-02-11

Increased caloric intake in dietary obesity could be driven by central mechanisms that regulate reward-seeking behavior. The mesolimbic dopamine system, and the nucleus accumbens in particular, underlies both food and drug reward. We investigated whether rat dietary obesity is linked to changes in dopaminergic neurotransmission in that region. ...

PubMed Central

91
Acute cocaine increases interleukin-1? mRNA and immunoreactive cells in the cortex and nucleus accumbens.
2011-03-12

The cytokine, interleukin-1? (IL1?) is a sleep regulatory substance whose expression is enhanced in response to neuronal stimulation. In this study, IL1? mRNA and immunoreactivity (IR) are evaluated after acute cocaine. First, IL1? mRNA levels were measured at the start or end of the light period after saline or acute exposure to a low dose of cocaine (5 mg/kg, intraperitoneal (ip)). IL1? mRNA ...

PubMed

92
Neurotransmitter Mechanisms in the Nucleus Accumbens ...
1981-06-30

... GLU projections from the neo- or allocortex have been found to terminate in nucleus accumbens and other forebrain and hypothalamic nuclei. ...

DTIC Science & Technology

93
R-(+)-HA-966, a glycine/NMDA receptor antagonist, selectively blocks the activation of the mesolimbic dopamine system by amphetamine.
1991-08-01

1. The effects of the glycine/NMDA receptor antagonist, (+)-HA-966 on the neurochemical and behavioural responses to amphetamine have been determined in the mouse and rat. 2. In vehicle-treated control mice, (+)-HA-966 (30-100 mg kg-1) did not affect dopamine synthesis in either the nucleus accumbens or striatum and was without marked effect on spontaneous locomotor activity. ...

PubMed

94
Injections of the selective adenosine A2A antagonist MSX-3 into the nucleus accumbens core attenuate the locomotor suppression induced by haloperidol in rats
2006-12-21

There is considerable evidence of interactions between adenosine A2A receptors and dopamine D2 receptors in striatal areas, and antagonists of the A2A receptor have been shown to reverse the motor effects of DA antagonists in animal models. The D2 antagonist haloperidol produces parkinsonism in humans, and ...

PubMed Central

95
Excitant amino acid projections from rat amygdala and thalamus to nucleus accumbens
1988-04-01

High affinity uptake of D-(/sup 3/H)aspartate, (/sup 3/H)choline and (/sup 3/H)GABA was examined in synaptosomal-containing preparations of rat nucleus accumbens septi 7 to 10 days after unilateral or bilateral N-methyl-D-aspartate lesions confined to the parataenial nucleus of the thalamus or the basolateral nucleus of the amygdala. Uptake of both D-(/sup 3/H)aspartate and ...

Energy Citations Database

96
Differential regulation of 5-hydroxytryptamine release by GABAA and GABAB receptors in midbrain raphe nuclei and forebrain of rats.
1996-12-01

1. Extracellular 5-hydroxytryptamine (5-HT) was determined in dorsal raphe nucleus (DRN), median raphe nucleus (MRN) and nucleus accumbens by use of microdialysis in unanaesthetized rats. 2. Infusion of the gamma-aminobutyric acid (GABA)A receptor agonist muscimol into DRN and MRN resulted in decreased 5-HT in DRN and MRN, respectively. Muscimol infusion into nucleus ...

PubMed Central

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