Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways

It is of considerable translational importance whether depression is a form or a consequence of sickness behavior. Sickness behavior is a behavioral complex induced by infections and immune trauma and mediated by pro-inflammatory cytokines. It is an adaptive response that enhances recovery by conserving energy to combat acute inflammation. There are considerable phenomenological similarities between sickness behavior and depression, for example, behavioral inhibition, anorexia and weight loss, and melancholic (anhedonia), physio-somatic (fatigue, hyperalgesia, malaise), anxiety and neurocognitive symptoms. In clinical depression, however, a transition occurs to sensitization of immuno-inflammatory pathways, progressive damage by oxidative and nitrosative stress to lipids, proteins, and DNA, and autoimmune responses directed against self-epitopes. The latter mechanisms are the substrate of a neuroprogressive process, whereby multiple depressive episodes cause neural tissue damage and consequent functional and cognitive sequelae. Thus, shared immuno-inflammatory pathways underpin the physiology of sickness behavior and the pathophysiology of clinical depression explaining their partially overlapping phenomenology. Inflammation may provoke a Janus-faced response with a good, acute side, generating protective inflammation through sickness behavior and a bad, chronic side, for example, clinical depression, a lifelong disorder with positive feedback loops between (neuro)inflammation and (neuro)degenerative processes following less well defined triggers

Stress-Induced Reinstatement of Drug Seeking: 20 Years of Progress

In human addicts, drug relapse and craving are often provoked by stress. Since 1995, this clinical scenario has been studied using a rat model of stress-induced reinstatement of drug seeking. Here, we first discuss the generality of stress-induced reinstatement to different drugs of abuse, different stressors, and different behavioral procedures. We also discuss neuropharmacological mechanisms, and brain areas and circuits controlling stress-induced reinstatement of drug seeking. We conclude by discussing results from translational human laboratory studies and clinical trials that were inspired by results from rat studies on stress-induced reinstatement. Our main conclusions are (1) The phenomenon of stress-induced reinstatement, first shown with an intermittent footshock stressor in rats trained to self-administer heroin, generalizes to other abused drugs, including cocaine, methamphetamine, nicotine, and alcohol, and is also observed in the conditioned place preference model in rats and mice. This phenomenon, however, is stressor specific and not all stressors induce reinstatement of drug seeking. (2) Neuropharmacological studies indicate the involvement of corticotropin-releasing factor (CRF), noradrenaline, dopamine, glutamate, kappa/dynorphin, and several other peptide and neurotransmitter systems in stress-induced reinstatement. Neuropharmacology and circuitry studies indicate the involvement of CRF and noradrenaline transmission in bed nucleus of stria terminalis and central amygdala, and dopamine, CRF, kappa/dynorphin, and glutamate transmission in other components of the mesocorticolimbic dopamine system (ventral tegmental area, medial prefrontal cortex, orbitofrontal cortex, and nucleus accumbens). (3) Translational human laboratory studies and a recent clinical trial study show the efficacy of alpha-2 adrenoceptor agonists in decreasing stress-induced drug craving and stress-induced initial heroin lapse

Desipramine Inhibits Histamine H1 Receptor-Induced Ca2+ Signaling in Rat Hypothalamic Cells

The hypothalamus in the brain is the main center for appetite control and integrates signals from adipose tissue and the gastrointestinal tract. Antidepressants are known to modulate the activities of hypothalamic neurons and affect food intake, but the cellular and molecular mechanisms by which antidepressants modulate hypothalamic function remain unclear. Here we have investigated how hypothalamic neurons respond to treatment with antidepressants, including desipramine and sibutramine. In primary cultured rat hypothalamic cells, desipramine markedly suppressed the elevation of intracellular Ca2+ evoked by histamine H1 receptor activation. Desipramine also inhibited the histamine-induced Ca2+ increase and the expression of corticotrophin-releasing hormone in hypothalamic GT1-1 cells. The effect of desipramine was not affected by pretreatment with prazosin or propranolol, excluding catecholamine reuptake activity of desipramine as an underlying mechanism. Sibutramine which is also an antidepressant but decreases food intake, had little effect on the histamine-induced Ca2+ increase or AMP-activated protein kinase activity. Our results reveal that desipramine and sibutramine have different effects on histamine H1 receptor signaling in hypothalamic cells and suggest that distinct regulation of hypothalamic histamine signaling might underlie the differential regulation of food intake between antidepressants

A model for homeopathic remedy effects: low dose nanoparticles, allostatic cross-adaptation, and time-dependent sensitization in a complex adaptive system

BACKGROUND: This paper proposes a novel model for homeopathic remedy action on living systems. Research indicates that homeopathic remedies (a) contain measurable source and silica nanoparticles heterogeneously dispersed in colloidal solution; (b) act by modulating biological function of the allostatic stress response network (c) evoke biphasic actions on living systems via organism-dependent adaptive and endogenously amplified effects; (d) improve systemic resilience. DISCUSSION: The proposed active components of homeopathic remedies are nanoparticles of source substance in water-based colloidal solution, not bulk-form drugs. Nanoparticles have unique biological and physico-chemical properties, including increased catalytic reactivity, protein and DNA adsorption, bioavailability, dose-sparing, electromagnetic, and quantum effects different from bulk-form materials. Trituration and/or liquid succussions during classical remedy preparation create “top-down” nanostructures. Plants can biosynthesize remedy-templated silica nanostructures. Nanoparticles stimulate hormesis, a beneficial low-dose adaptive response. Homeopathic remedies prescribed in low doses spaced intermittently over time act as biological signals that stimulate the organism’s allostatic biological stress response network, evoking nonlinear modulatory, self-organizing change. Potential mechanisms include time-dependent sensitization (TDS), a type of adaptive plasticity/metaplasticity involving progressive amplification of host responses, which reverse direction and oscillate at physiological limits. To mobilize hormesis and TDS, the remedy must be appraised as a salient, but low level, novel threat, stressor, or homeostatic disruption for the whole organism. Silica nanoparticles adsorb remedy source and amplify effects. Properly-timed remedy dosing elicits disease-primed compensatory reversal in direction of maladaptive dynamics of the allostatic network, thus promoting resilience and recovery from disease. SUMMARY: Homeopathic remedies are proposed as source nanoparticles that mobilize hormesis and time-dependent sensitization via non-pharmacological effects on specific biological adaptive and amplification mechanisms. The nanoparticle nature of remedies would distinguish them from conventional bulk drugs in structure, morphology, and functional properties. Outcomes would depend upon the ability of the organism to respond to the remedy as a novel stressor or heterotypic biological threat, initiating reversals of cumulative, cross-adapted biological maladaptations underlying disease in the allostatic stress response network. Systemic resilience would improve. This model provides a foundation for theory-driven research on the role of nanomaterials in living systems, mechanisms of homeopathic remedy actions and translational uses in nanomedicine

A Single-Blind randomized controlled trial to evaluate the effect of extended counseling on uptake of pre-antiretroviral care in eastern uganda

<p>Abstract</p> <p>Background</p> <p>Many newly screened people living with HIV (PLHIV) in Sub-Saharan Africa do not understand the importance of regular pre-antiretroviral (ARV) care because most of them have been counseled by staff who lack basic counseling skills. This results in low uptake of pre-ARV care and late treatment initiation in resource-poor settings. The effect of providing post-test counseling by staff equipped with basic counseling skills, combined with home visits by community support agents on uptake of pre-ARV care for newly diagnosed PLHIV was evaluated through a randomized intervention trial in Uganda.</p> <p>Methods</p> <p>An intervention trial was performed consisting of post-test counseling by trained counselors, combined with monthly home visits by community support agents for continued counseling to newly screened PLHIV in Iganga district, Uganda between July 2009 and June 2010, Participants (N = 400) from three public recruitment centres were randomized to receive either the intervention, or the standard care (the existing post-test counseling by ARV clinic staff who lack basic training in counseling skills), the control arm. The outcome measure was the proportion of newly screened and counseled PLHIV in either arm who had been to their nearest health center for clinical check-up in the subsequent three months +2 months. Treatment was randomly assigned using computer-generated random numbers. The statistical significance of differences between the two study arms was assessed using chi-square and t-tests for categorical and quantitative data respectively. Risk ratios and 95% confidence intervals were used to assess the effect of the intervention.</p> <p>Results</p> <p>Participants in the intervention arm were 80% more likely to accept (take up) pre-ARV care compared to those in the control arm (RR 1.8, 95% CI 1.4-2.1). No adverse events were reported.</p> <p>Conclusions</p> <p>Provision of post-test counseling by staff trained in basic counseling skills, combined with home visits by community support agents had a significant effect on uptake of pre-ARV care and appears to be a cost-effective way to increase the prerequisites for timely ARV initiation.</p> <p>Trial registration</p> <p>The trial was registered by Current Controlled Trials Ltd C/OBioMed Central Ltd as <a href="http://www.controlled-trials.com/ISRCTN94133652">ISRCTN94133652</a> and received financial support from Sida and logistical support from the European Commission.</p

The development of sensitization to the psychomotor stimulant effects of amphetamine is enhanced in a novel environment

Two experiments were designed to assess the effect of a “novel” environment on the development of sensitization to the psychomotor activating effects of d -amphetamine. In the first experiment, rats with a unilateral 6-hydroxydopamine lesion of the mesostriatal dopamine system received ten daily injections of amphetamine (2 mg/kg), either in their home cages or in novel test cages. The home and novel cages were physically identical (cylindrical transparent buckets), but one group lived and were tested in these cages, whereas the other group was transported from the stainless steel hanging cages where they lived to these novel test cages, for each test session. The first injection of amphetamine produced significantly more rotational behavior in animals tested in a novel environment than in animals tested at home. In addition, animals tested in a novel environment showed greater sensitization than animals tested at home, so the difference between the two groups was even more pronounced following the last injection. In a second experiment, locomotor activity was quantified in rats that received ten injections of either saline or 1.5 mg/kg amphetamine, in their home cages or in a physically identical novel environment. Again, there was a significantly greater locomotor response to the first injection of amphetamine, and greater sensitization, in animals tested in a novel environment than in animals tested at home. These data indicate that environmental factors can exert a large effect on the susceptibility to sensitization, and mechanisms by which this may occur are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46345/1/213_2005_Article_BF02246217.pd