Risk-Based Decision Making: A Systematic Scoping Review of Animal Models and a Pilot Study on the Effects of Sleep Deprivation in Rats.

Animals, including humans, frequently make decisions involving risk or uncertainty. Different strategies in these decisions can be advantageous depending the circumstances. Short sleep duration seems to be associated with more risky decisions in humans.

Sleep and Microdialysis: An Experiment and a Systematic Review of Histamine and Several Amino Acids.

Sleep seems essential to proper functioning of the prefrontal cortex (PFC). The role of different neurotransmitters has been studied, mainly the catecholamines and serotonin. Less attention has been paid to the amino acid transmitters and histamine.

Brain Microdialysate Monoamines in Relation to Circadian Rhythms, Sleep, and Sleep Deprivation - a Systematic Review, Network Meta-analysis, and New Primary Data.

Disruption of the monoaminergic system, e.g. by sleep deprivation (SD), seems to promote certain diseases.

Intracerebral Adenosine During Sleep Deprivation: A Meta-Analysis and New Experimental Data.

The neuroregulator adenosine is involved in sleep-wake control. Basal forebrain (BF) adenosine levels increase during sleep deprivation. Only a few studies have addressed the effect of sleep deprivation on extracellular adenosine concentrations in other brain regions.

Differential Effects of Deep Brain Stimulation of the Internal Capsule and the Striatum on Excessive Grooming in Sapap3 Mutant Mice.

Background: Deep brain stimulation (DBS) is an effective treatment for patients with obsessive-compulsive disorder (OCD) that do not respond to conventional therapies. Although the precise mechanism of action of DBS remains unknown, modulation of activity in corticofugal fibers originating in the prefrontal cortex is thought to underlie its beneficial effects in OCD.

Methods: To gain more mechanistic insight into DBS in OCD, we used Sapap3 mutant mice.

Prazosin addition to fluvoxamine: A preclinical study and open clinical trial in OCD.

The efficacy of selective serotonin reuptake inhibitors (SRIs) in psychiatric disorders may be "augmented" through the addition of atypical antipsychotic drugs. A synergistic increase in dopamine (DA) release in the prefrontal cortex has been suggested to underlie this augmentation effect, though the mechanism of action is not clear yet. We used in vivo microdialysis in rats to study DA release following the administration of combinations of fluvoxamine (10 mg/kg) and quetiapine (10 mg/kg) with various monoamine-related drugs.

Alterations in blood glucose and plasma glucagon concentrations during deep brain stimulation in the shell region of the nucleus accumbens in rats.

Deep brain stimulation (DBS) of the nucleus accumbens (NAc) is an effective therapy for obsessive compulsive disorder (OCD) and is currently under investigation as a treatment for eating disorders. DBS of this area is associated with altered food intake and pharmacological treatment of OCD is associated with the risk of developing type 2 diabetes. Therefore we examined if DBS of the NAc-shell (sNAc) influences glucose metabolism.

Instrumental learning: an animal model for sleep dependent memory enhancement.

The relationship between learning and sleep is multifaceted; learning influences subsequent sleep characteristics, which may in turn influence subsequent memory. Studies in humans indicate that sleep may not only prevent degradation of acquired memories, but even enhance performance without further practice. In a rodent instrumental learning task, individual differences occur in how fast rats learn to associate lever pressing with food reward.

Deep brain stimulation of the accumbens increases dopamine, serotonin, and noradrenaline in the prefrontal cortex.

Deep brain stimulation (DBS) of the nucleus accumbens (NAc) is effective in treatment-refractory obsessive-compulsive disorder and major depressive disorder. However, little is known about the neurobiological mechanisms underlying the rapid and effective changes of DBS. One of the hypotheses is that DBS modulates activity of monoamine neurotransmitters.

Spatial reversal learning is robust to total sleep deprivation.

Sleep deprivation affects cognitive functions that depend on the prefrontal cortex (PFC) such as cognitive flexibility, and the consolidation of newly learned information. The identification of cognitive processes that are either robustly sensitive or robustly insensitive to the same experimental sleep deprivation procedure, will allow us to better focus on the specific effects of sleep on cognition, and increase understanding of the mechanisms involved. In the present study we investigate whether sleep deprivation differentially affects the two separate cognitive processes of acquisition and consolidation of a spatial reversal task.

Switch-task performance in rats is disturbed by 12 h of sleep deprivation but not by 12 h of sleep fragmentation.

Study Objectives: Task-switching is an executive function involving the prefrontal cortex. Switching temporarily attenuates the speed and/or accuracy of performance, phenomena referred to as switch costs. In accordance with the idea that prefrontal function is particularly sensitive to sleep loss, switch-costs increase during prolonged waking in humans.

Unilateral deep brain stimulation in the nucleus accumbens core does not affect local monoamine release.

Recent publications have shown promising results of deep brain stimulation (DBS) in the nucleus accumbens for patients with obsessive compulsive disorder and major depressive disorder. Despite its increasing application in the clinical setting, the neurobiological mechanism of action of DBS is still uncertain. One of the possible effects of DBS might be phasic or tonic changes in monoamine release either locally in the target area or in a distant, connected region.

WITHDRAWN: Is acute tryptophan depletion a valid method to assess central serotonergic function?

This article has been withdrawn at the request of the editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.

A new automated method for rat sleep deprivation with minimal confounding effects on corticosterone and locomotor activity.

The function of sleep in physiology, behaviour and cognition has become a primary focus of neuroscience. Its study inevitably includes experimental sleep deprivation designs. However, concerns exist regarding confounds like stress, increased locomotor activity levels, and decreased motivation to perform operant tasks induced by the methods employed.

Single-cell and population coding of expected reward probability in the orbitofrontal cortex of the rat.

The orbitofrontal cortex (OFC) has been implicated in decision-making under uncertainty, but it is unknown how information about the probability or uncertainty of future reward is coded by single orbitofrontal neurons and ensembles. We recorded neuronal ensembles in rat OFC during an olfactory discrimination task in which different odor stimuli predicted different reward probabilities. Single-unit firing patterns correlated to the expected reward probability primarily within an immobile waiting period before reward delivery but also when the rat executed movements toward the reward site.

Intermediate filament transcription in astrocytes is repressed by proteasome inhibition.

Increased expression of the astrocytic intermediate filament protein glial fibrillary acidic protein (GFAP) is a characteristic of astrogliosis. This process occurs in the brain during aging and neurodegeneration and coincides with impairment of the ubiquitin proteasome system. Inhibition of the proteasome impairs protein degradation; therefore, we hypothesized that the increase in GFAP may be the result of impaired proteasomal activity in astrocytes.

Medial prefrontal serotonin in the rat is involved in goal-directed behaviour when affect guides decision making.

Rationale: Across species, serotonin (5-HT) depletion in the prefrontal cortex (PFC) has been shown to cause impaired performance on tests of cognitive flexibility and the processing of affective information (e.g. information with an 'emotional' content).

Serial reversal learning and acute tryptophan depletion.

Cognitive flexibility (i.e. the ability to adapt goal-directed behaviour in response to changed environmental demands) has repeatedly been shown to depend on the prefrontal cortex (PFC).

Lack of evidence for reduced prefrontal cortical serotonin and dopamine efflux after acute tryptophan depletion.

Rationale: Acute tryptophan depletion (ATD) is a widely used method to study the role of serotonin (5-HT) in affect and cognition. ATD results in a strong but transient decrease in plasma tryptophan and central 5-HT synthesis and availability. Although its use is widespread, the evidence that the numerous functional effects of ATD are caused by actual changes in 5-HT neuronal release is not very strong.

Dopamine and noradrenaline efflux in the medial prefrontal cortex during serial reversals and extinction of instrumental goal-directed behavior.

The prefrontal cortex (PFC) of the rat supports cognitive flexibility, the ability to spontaneously adapt goal-directed behavior in response to radically changing situational demands. We have shown previously that transient inactivation of the rat medial PFC (mPFC) impairs initial reversal learning in a spatial 2-lever discrimination task. Given the importance of dopamine (DA) for PFC function, we studied DA (and noradrenaline [NA]) efflux in the mPFC during reversal learning.

Individual differences in dopamine efflux in nucleus accumbens shell and core during instrumental learning.

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 simultaneously measured dopamine efflux in the shell and core accumbens subareas using in vivo microdialysis. Dopamine efflux was increased during each session in all areas.

Noradrenergic action in prefrontal cortex in the late stage of memory consolidation.

These experiments investigated the role of the noradrenergic system in the late stage of memory consolidation and in particular its action at beta receptors in the prelimbic region (PL) of the prefrontal cortex in the hours after training. Rats were trained in a rapidly acquired, appetitively motivated foraging task based on olfactory discrimination. They were injected with a beta adrenergic receptor antagonist into the PL 5 min or 2 h after training and tested 48 h later.

Noradrenaline and dopamine efflux in the prefrontal cortex in relation to appetitive classical conditioning.

We trained rats to learn that an auditory stimulus predicted delivery of reward pellets in the Skinner box. After 2 d of training, we measured changes in efflux of noradrenaline (NA) and dopamine (DA) in the medial prefrontal cortex using microdialysis on the third day. Animals were subjected to a normal rewarded session and an extinction session, in which the auditory stimulus was presented alone.

Molecular changes underlying reduced pineal melatonin levels in Alzheimer disease: alterations in preclinical and clinical stages.

A disturbed sleep-wake rhythm is common in Alzheimer disease (AD) patients and correlated with decreased melatonin levels and a disrupted circadian melatonin rhythm. Melatonin levels in the cerebrospinal fluid are decreased during the progression of AD neuropathology (as determined by the Braak stages), already in cognitively intact subjects with the earliest AD neuropathology (Braak stages I-II) (preclinical AD). To investigate the molecular mechanisms behind the decreased melatonin levels, we measured monoamines and mRNA levels of enzymes of the melatonin synthesis and its noradrenergic regulation in pineal glands from 18 controls, 33 preclinical AD subjects, and 25 definite AD patients.

The NMDA-receptor antagonist MK-801 selectively disrupts reversal learning in rats.

We tested the hypothesis that inhibition of NMDA-receptors in rats would lead to a selective impairment of reversal learning in a serial reversal task in the Skinner box. Low doses of MK-801 (0.025 and 0.