The α-7 Nicotinic Receptor Positive Allosteric Modulator Alleviates Lipopolysaccharide Induced Depressive-like Behavior by Regulating Microglial Function, Trophic Factor, and Chloride Transporters in Mice.

Neuroinflammation contributes to the pathophysiology of major depressive disorder (MDD) by inducing neuronal excitability via dysregulation of microglial brain-derived neurotrophic factor (BDNF), Na-K-Cl cotransporter-1 (NKCC1), and K-Cl cotransporter-2 (KCC2) due to activation of BDNF-tropomyosin receptor kinase B (TrkB) signaling. Allosteric modulation of α7 nAChRs has not been investigated on BDNF, KCC2, and NKCC1 during LPS-induced depressive-like behavior. Therefore, we examined the effects of PNU120596, an α7 nAChR positive allosteric modulator, on the expression of BDNF, KCC2, and NKCC1 in the hippocampus and prefrontal cortex using Western blot analysis, immunofluorescence assay, and real-time polymerase chain reaction. The effects of ANA12, a TrkB receptor antagonist, on LPS-induced cognitive deficit and depressive-like behaviors were determined using the Y-maze, tail suspension test (TST), and forced swim test (FST). Pharmacological interactions between PNU120596 and ANA12 were also examined. Experiments were conducted in male C57BL/6J mice. LPS administration (1 mg/kg) resulted in increased expression of BDNF and the NKCC1/KCC2 ratio and decreased expression of KCC2 in the hippocampus and prefrontal cortex. PNU120596 pretreatment (4 mg/kg) attenuated the LPS-induced increase in the expression of BDNF and NKCC1/KCC2 ratio and the reduction in KCC2 expression in these brain regions. In addition, ANA12 (0.25 or 0.50 mg/kg) reduced the LPS-induced cognitive deficit and depressive-like behaviors measured by a reduced spontaneous alternation in the Y-maze and increased immobility duration in TST and FST. Coadministration of PNU120596 (1 mg/kg) and ANA12 (0.25 mg/kg) prevented the LPS-induced cognitive deficit and depressive-like behaviors. Overall, PNU120596 prevented the LPS-induced depressive-like behavior by likely decreasing neuronal excitability via targeting microglial α7 nAChR in the hippocampus and prefrontal cortex.

Glial Glutamate Transporter Modulation Prevents Development of Complete Freund's Adjuvant-Induced Hyperalgesia and Allodynia in Mice.

Glial glutamate transporter (GLT-1) modulation in the hippocampus and anterior cingulate cortex (ACC) is critically involved in nociceptive pain. The objective of the study was to investigate the effects of 3-[[(2-methylphenyl) methyl] thio]-6-(2-pyridinyl)-pyridazine (LDN-212320), a GLT-1 activator, against microglial activation induced by complete Freund's adjuvant (CFA) in a mouse model of inflammatory pain. Furthermore, the effects of LDN-212320 on the protein expression of glial markers, such as ionized calcium-binding adaptor molecule 1 (Iba1), cluster of differentiation molecule 11b (CD11b), mitogen-activated protein kinases (p38), astroglial GLT-1, and connexin 43 (CX43), were measured in the hippocampus and ACC following CFA injection using the Western blot analysis and immunofluorescence assay. The effects of LDN-212320 on the pro-inflammatory cytokine interleukin-1ß (IL-1ß) in the hippocampus and ACC were also assessed using an enzyme-linked immunosorbent assay. Pretreatment with LDN-212320 (20 mg/kg) significantly reduced the CFA-induced tactile allodynia and thermal hyperalgesia. The anti-hyperalgesic and anti-allodynic effects of LDN-212320 were reversed by the GLT-1 antagonist DHK (10 mg/kg). Pretreatment with LDN-212320 significantly reduced CFA-induced microglial Iba1, CD11b, and p38 expression in the hippocampus and ACC. LDN-212320 markedly modulated astroglial GLT-1, CX43, and, IL-1ß expression in the hippocampus and ACC. Overall, these results suggest that LDN-212320 prevents CFA-induced allodynia and hyperalgesia by upregulating astroglial GLT-1 and CX43 expression and decreasing microglial activation in the hippocampus and ACC. Therefore, LDN-212320 could be developed as a novel therapeutic drug candidate for chronic inflammatory pain.

Prior stress and vasopressin promote corticotropin-releasing factor inhibition of serotonin release in the central nucleus of the amygdala.

Corticotropin-releasing factor (CRF) is essential for coordinating endocrine and neural responses to stress, frequently facilitated by vasopressin (AVP). Previous work has linked CRF hypersecretion, binding site changes, and dysfunctional serotonergic transmission with anxiety and affective disorders, including clinical depression. Crucially, CRF can alter serotonergic activity. In the dorsal raphé nucleus and serotonin (5-HT) terminal regions, CRF effects can be stimulatory or inhibitory, depending on the dose, site, and receptor type activated. Prior stress alters CRF neurotransmission and CRF-mediated behaviors. Lateral, medial, and ventral subdivisions of the central nucleus of the amygdala (CeA) produce CRF and coordinate stress responsiveness. The purpose of these experiments was to determine the effect of intracerebroventricular (icv) administration of CRF and AVP on extracellular 5-HT as an index of 5-HT release in the CeA, using in vivo microdialysis in freely moving rats and high performance liquid chromatography (HPLC) analysis. We also examined the effect of prior stress (1 h restraint, 24 h prior) on CRF- and AVP-mediated release of 5-HT within the CeA. Our results show that icv CRF infusion in unstressed animals had no effect on 5-HT release in the CeA. Conversely, in rats with prior stress, CRF caused a profound dose-dependent decrease in 5-HT release within the CeA. This effect was long-lasting (240 min) and was mimicked by CRF plus AVP infusion without stress. Thus, prior stress and AVP functionally alter CRF-mediated neurotransmission and sensitize CRF-induced inhibition of 5-HT release, suggesting that this is a potential mechanism underlying stress-induced affective reactivity in humans.

Working Toward a Gold Standard: The Severity of Ethanol Withdrawal Scale (SEWS) Versus the Clinical Institute Withdrawal Assessment Alcohol Scale (CIWA-Ar).

AIM: Proving the Severity of Ethanol Withdrawal Scale (SEWS) significantly reduces Alcohol Withdrawal Syndrome (AWS) treatment Time on Medication Protocol (TOMP). METHOD: Head-to-head Quality Assurance outcome compared separate cohorts of SEWS or Clinical Institute Withdrawal Assessment Alcohol Scale, Revised (CIWA-Ar) data using Student's t and Wilcoxon tests. RESULTS: SEWS-driven treatment (n = 244) reduced TOMP to 2.2 days versus 3.4 days for CIWA-Ar (n = 137); P < 0.0001. CONCLUSION: The SEWS is the superior measure of AWS symptoms.

The Effect of an α-7 Nicotinic Allosteric Modulator PNU120596 and NMDA Receptor Antagonist Memantine on Depressive-like Behavior Induced by LPS in Mice: The Involvement of Brain Microglia.

Nicotinic acetylcholine receptors (nAChRs), particularly the α7 nAChR, play a critical role in neuroinflammation and microglial activation associated with major depressive disorder (MDD). Microglial quinolinic acid (QUIN), which is synthesized by 3-hydroxyanthranilic acid dioxygenase (HAAO), is an N-methyl-D-aspartate (NMDA) receptor agonist and has been implicated in the development of MDD-related symptoms. In the present study, we assessed the effects of PNU120596, an α7 nAChR positive allosteric modulator (PAM), on HAAO expression and QUIN formation in the hippocampus and prefrontal cortex. We also investigated the effects of memantine, an NMDA receptor antagonist, alone and in combination with PNU120596 on cognitive deficit and depressive-like behaviors induced by lipopolysaccharide (LPS) in mice using the Y-maze and forced swim test, respectively. LPS (1 mg/kg, i.p.) elevated HAAO expression and QUIN formation in the hippocampus and prefrontal cortex, which were reduced with pretreatment with PNU120596 (4 mg/kg, i.p.). Furthermore, memantine (1 or 3 mg/kg, i.p.) prevented the cognitive deficit and depressive-like behaviors induced by LPS in mice. Together, these results suggest that the antidepressant-like effects of PNU120596 are mediated by attenuation of LPS-induced QUIN formation. Therefore, α7 nAChR PAM could be a potential therapeutic candidate for MDD associated with neurotoxic glutamatergic transmission.

A Double-Blind Placebo-Controlled, Randomized Trial of Divalproex Sodium for Posttraumatic Irritability Greater Than 1 Year After Mild to Moderate Traumatic Brain Injury.

OBJECTIVE: Posttraumatic irritability after traumatic brain injury (TBI) may become a chronic problem and contribute to impaired everyday function, either alone or in combination with alcohol use disorder. The authors hypothesized that divalproex sodium (VPA) would improve posttraumatic irritability and result in lessened alcohol use. METHODS: This randomized, placebo-controlled double-blind clinical trial recruited participants with an index TBI occurring 1 or more years prior to enrollment, a history of alcohol use disorder, and posttraumatic irritability corroborated by a knowledgeable informant. An 8-item subset of the Agitated Behavior Scale served as the primary outcome measure of VPA efficacy. Doses of VPA were titrated to standard serum concentrations of 50 µg/ml to 100 µg/ml. RESULTS: Forty-eight persons completed this clinical trial (VPA, N=22; placebo, N=26). At baseline, participants rated their posttraumatic irritability as less severe than did their informants (p<0.05). During the trial, informants reported significant and sustained reduction of posttraumatic irritability (p=0.03) in the study participants. Biweekly averages during drug exposure confirmed this (p<0.03, Cohen's d=0.44). Treatment efficacy was not related to measures of anxiety, posttraumatic stress disorder, sedation, or veteran versus nonveteran status. Alcohol use did not change as a result of treatment. There were no serious adverse events. CONCLUSIONS: This study demonstrated an effect of VPA on posttraumatic irritability, and VPA was well tolerated. Further definition of treatment efficacy and safety requires a large-scale multisite trial, using a randomized, double-blind placebo-controlled design.

Orexin 1 Receptor Antagonism in the Basolateral Amygdala Shifts the Balance From Pro- to Antistress Signaling and Behavior.

BACKGROUND: Stress produces differential behavioral responses through select molecular modifications to specific neurocircuitry elements. The orexin (Orx) system targets key components of this neurocircuitry in the basolateral amygdala (BLA). METHODS: We assessed the contribution of intra-BLA Orx1 receptors (Orx1Rs) in the expression of stress-induced phenotypes of mice. Using the Stress Alternatives Model, a social stress paradigm that produces two behavioral phenotypes, we characterized the role of intra-BLA Orx1R using acute pharmacological inhibition (SB-674042) and genetic knockdown (AAV-U6-Orx1R-shRNA) strategies. RESULTS: In the BLA, we observed that Orx1R (Hcrtr1) messenger RNA is predominantly expressed in CamKIIα+ glutamatergic neurons and rarely in GABAergic (gamma-aminobutyric acidergic) cells. While there is a slight overlap in Hcrtr1 and Orx2 receptor (Hcrtr2) messenger RNA expression in the BLA, we find that these receptors are most often expressed in separate cells. Antagonism of intra-BLA Orx1R after phenotype formation shifted behavioral expression from stress-sensitive (Stay) to stress-resilient (Escape) responses, an effect that was mimicked by genetic knockdown. Acute inhibition of Orx1R in the BLA also reduced contextual and cued fear freezing responses in Stay animals. This phenotype-specific behavioral change was accompanied by biased molecular transcription favoring Hcrtr2 over Hcrtr1 and Mapk3 over Plcb1 cell signaling cascades and enhanced Bdnf messenger RNA. CONCLUSIONS: Functional reorganization of intra-BLA gene expression is produced by antagonism of Orx1R, which promotes elevated Hcrtr2, greater Mapk3, and increased Bdnf expression. Together, these results provide evidence for a receptor-driven mechanism that balances pro- and antistress responses within the BLA.

Psychological Adaptive Mechanism Maturity, Age, and Depression Symptoms in Advanced-Stage Cancer Patients.

Background: Previously, we reported that the maturity of Psychological Adaptive Mechanism (PAM; alternatively, ego defense mechanism) endorsement, but not depression symptom severity, predicted 5-year survival rates in adult cancer patients and that study controlled for age as a significant variable. In this investigation, we hypothesized that greater PAM maturity would correlate significantly with age and with fewer depression symptoms in a larger sample. Methods: In this cross-section study, adult cancer outpatients (N=293) completed the Defense Style Questionnaire (DSQ), the Beck Depression Inventory (BDI), and provided additional clinical data. Spearman's correlation and multiple regression modeling provided statistical tests of the study hypotheses. Results: Contrary to our hypothesis, DSQ PAM maturity endorsement did not correlate significantly with increasing age. Greater PAM maturity ratio on the DSQ (p<0.0001) and current antidepressant use (p<0.05), however, both provided inverse associations with total BDI symptom frequency (p<0.01). Age was inversely associated with BDI mood (p<0.0001) and somatic scores (p<0.04). Items that worsened BDI symptom frequency included self-reported mood-altering anti-cancer medications and any psychiatric history. Cancer stage, time since diagnosis, and chemotherapy treatment did not correlate with DSQ or BDI scores. Multiple regression analysis found that the correlated items accounted for 17.2% of the variance in mood symptoms and 4.9% in somatic symptoms. Specifically, adaptive maturity and age associated with fewer depression symptoms, while cancer medications affecting mood, and a previous psychiatric history each predicted higher frequency of depression scores. Conclusion: The results suggest that PAM maturity likely predicts fewer depression symptoms while younger age associates with more depression symptoms in this clinical sample. Centrally, acting cancer medications, such as glucocorticoids, and any history of psychiatric disorder correlated with increased depression symptom frequencies. In this cross-section study, antidepressant medications indicated higher frequencies of depressive symptoms, likely reflecting their use in persons previously diagnosed with depression. Further research should target factors that improve PAM maturity as a potential treatment target, especially in younger age groups.

Psychological Adaptive Mechanism Maturity Predicts Good Outcomes in Treatment for Refractory PTSD.

Background: Post-traumatic Stress Disorder (PTSD) severity follows a bell-shaped curve ranging from mild to severe. Those in the severe range often receive the most intensive treatments, including targeted residential rehabilitation stays. These are expensive and welcome ways to improve their effectiveness. We hypothesized that positive change among subjects treated in a 45-day residential rehabilitation format would be associated with the maturity levels of measurable Psychological Adaptive Mechanisms (PAMs), alternately ego defense mechanisms. Methods: In this association study, adult male patients (N = 115) with a history of combat related PTSD treated in a residential rehabilitation setting completed the Defense Style Questionnaire (DSQ) on admission, as well as the Post-Traumatic Stress Disorder Checklist-Military Version (PCL-M) and the Mississippi Scale for Combat-Related Post-traumatic Stress Disorder (M-PTSD) on admission and again at discharge. This allowed prospectively calculated change scores on each of the PTSD measures for each patient. The change scores allowed association testing with averaged admission DSQ scores using Pearson's correlation probability with significance held at p < 0.05. Results: As hypothesized, averaged individual Mature scores on the DSQ were associated with improved change scores on both the PCL-M (p = 0.03) and the M-PTSD (p = 0.04). By contrast neither averaged DSQ Neurotic or Immature scores associated significantly with either PTSD scale change scores. Conclusion: These results, the first of their kind to our knowledge, suggest that patients presenting with predominantly Mature level PAMs are likely to benefit from residential rehabilitation treatment of PTSD. By contrast, those presenting with Neurotic or Immature PAMs predominantly are less likely to encounter positive change in this type of treatment. Although residential treatment is often reserved for the most refractory PTSD cases, it appears that those endorsing Mature level PAMs will make use of residential treatment whereas other forms of treatment may be better suited to those with Neurotic and Immature adjustment mechanisms.

Interaction between CO2-consuming autotrophy and CO2-producing heterotrophy in non-axenic phototrophic biofilms.

As the effects of climate change become increasingly evident, the need for effective CO2 management is clear. Microalgae are well-suited for CO2 sequestration, given their ability to rapidly uptake and fix CO2. They also readily assimilate inorganic nutrients and produce a biomass with inherent commercial value, leading to a paradigm in which CO2-sequestration, enhanced wastewater treatment, and biomass generation could be effectively combined. Natural non-axenic phototrophic cultures comprising both autotrophic and heterotrophic fractions are particularly attractive in this endeavour, given their increased robustness and innate O2-CO2 exchange. In this study, the interplay between CO2-consuming autotrophy and CO2-producing heterotrophy in a non-axenic phototrophic biofilm was examined. When the biofilm was cultivated under autotrophic conditions (i.e. no organic carbon), it grew autotrophically and exhibited CO2 uptake. After amending its growth medium with organic carbon (0.25 g/L glucose and 0.28 g/L sodium acetate), the biofilm rapidly toggled from net-autotrophic to net-heterotrophic growth, reaching a CO2 production rate of 60 µmol/h after 31 hours. When the organic carbon sources were provided at a lower concentration (0.125 g/L glucose and 0.14 g/L sodium acetate), the biofilm exhibited distinct, longitudinally discrete regions of heterotrophic and autotrophic metabolism in the proximal and distal halves of the biofilm respectively, within 4 hours of carbon amendment. Interestingly, this upstream and downstream partitioning of heterotrophic and autotrophic metabolism appeared to be reversible, as the position of these regions began to flip once the direction of medium flow (and hence nutrient availability) was reversed. The insight generated here can inform new and important research questions and contribute to efforts aimed at scaling and industrializing algal growth systems, where the ability to understand, predict, and optimize biofilm growth and activity is critical.

A 5-Minute Cognitive Assessment for Safe Remote Use in Patients With COVID-19: Clinical Case Series.

BACKGROUND: Early clinical experience during the COVID-19 pandemic has begun to elucidate that the disease can cause brain function changes that may result in compromised cognition both acutely and during variable recovery periods. Reports on cognitive assessment of patients with COVID-19 are often limited to orientation alone. Further assessment may seem to create an inappropriate burden for patients with acute COVID-19, which is characterized by fatigue and confusion, and may also compromise examiner safety. OBJECTIVE: The aims of this study were to assess cognition in patients with COVID-19 as comprehensively as possible in a brief format, while observing safety precautions, and to establish a clear face value of the external validity of the assessment. METHODS: We adapted a brief cognitive assessment, previously applied to liver transplant candidates and medical/surgical inpatients, for remote use in patients hospitalized for COVID-19 treatment. Collecting quality assurance data from telephone-administered assessments, this report presents a series of 6 COVID-19 case vignettes to illustrate the use of this 5-minute assessment in the diagnosis and treatment of brain effects. Primary medical teams referred the cases for neuropsychiatric consultation. RESULTS: The age of the patients varied over four decades, and none of them were able to engage meaningfully with their surroundings on admission. On follow-up examination 6 to 10 days later, 4 of the 6 patients had recovered working memory, and only 1 had recovered calculation ability. Of the 6 patients, 2 were capable of complex judgment responses, while none of the cases completed frontal executive function testing in the normal range. CONCLUSIONS: Cognitive assessment in patients with COVID-19 using this remote examination reveals patterns of cognitive recovery that vary among cases and are far more complex than loss of orientation. In this series, testing of specific temporal, parietal, and frontal lobe functions suggests that calculation ability, judgment, and especially frontal executive functions may characterize the effects of COVID-19 on the brain. Used widely and serially, this examination method can potentially inform our understanding of the effects of COVID-19 on the brain and of healing from the virus.

A Novel System for Real-Time, In Situ Monitoring of CO2 Sequestration in Photoautotrophic Biofilms.

Climate change brought about by anthropogenic CO2 emissions has created a critical need for effective CO2 management solutions. Microalgae are well suited to contribute to efforts aimed at addressing this challenge, given their ability to rapidly sequester CO2 coupled with the commercial value of their biomass. Recently, microalgal biofilms have garnered significant attention over the more conventional suspended algal growth systems, since they allow for easier and cheaper biomass harvesting, among other key benefits. However, the path to cost-effectiveness and scaling up is hindered by a need for new tools and methodologies which can help evaluate, and in turn optimize, algal biofilm growth. Presented here is a novel system which facilitates the real-time in situ monitoring of algal biofilm CO2 sequestration. Utilizing a CO2-permeable membrane and a tube-within-a-tube design, the CO2 sequestration monitoring system (CSMS) was able to reliably detect slight changes in algal biofilm CO2 uptake brought about by light-dark cycling, light intensity shifts, and varying amounts of phototrophic biomass. This work presents an approach to advance our understanding of carbon flux in algal biofilms, and a base for potentially useful innovations to optimize, and eventually realize, algae biofilm-based CO2 sequestration.

Exercise improves high-fat diet- and ovariectomy-induced insulin resistance in rats with altered hepatic fat regulation.

A high-fat diet (HFD) and loss of endogenous estrogens increases the risk for type 2 diabetes (T2D) and insulin resistance. Although exercise is known to prevent and manage insulin resistance, the cellular mechanisms remain largely unknown, especially in the context of a combined HFD and endogenous estrogen loss via ovariectomy (OVX). This study uses female Wistar rats to assess the effect of diet, endogenous estrogens, an exercise on insulin resistance, serum hormones, hepatic AMPK, hepatic regulators of fat metabolism, and expression of signaling molecules of the brain reward pathway. The combination of the HFD/OVX increased the homeostatic model assessment of insulin resistance (HOMA-IR), the glucose-insulin (G-I) index, and the serum adiponectin and leptin values, and exercise decreased these factors. The combination of the HFD/OVX decreased hepatic pAMPK, and exercise restored hepatic pAMPK, an important regulator of fat and glucose metabolism. Furthermore, consumption of the HFD by rats with intact ovaries (and endogenous estrogens) did not result in these drastic changes compared to intact rats fed a standard diet, suggesting that the presence of estrogens provides whole body benefits. Additionally, the HFD decreased the hepatic protein expression of acetyl CoA carboxylase (ACC) and fatty acid synthase (FAS), two proteins involved in de novo lipid synthesis and increased the hepatic protein expression of lipoprotein lipase (LPL), a protein involved in fat storage. Finally, exercise increased mRNA expression of the dopamine D2 receptor and tyrosine hydroxylase in the dopaminergic neuron cell body region of the ventral tegmental area, which is a key component of the brain reward pathway. Overall, this study demonstrates that exercise prevents insulin resistance even when a HFD is combined with OVX, despite hepatic changes in ACC, FAS, and LPL.

Calcineurin signaling as a target for the treatment of alcohol abuse and neuroinflammatory disorders.

Converging lines of evidence point to a significant role of neuroinflammation in a host of psychiatric conditions, including alcohol use disorder, TBI, and PTSD. A complex interaction of both peripheral and central signaling underlies processes involved in neuroinflammation. Calcineurin is a molecule that sits at the nexus of these processes and has been clearly linked to a number of psychiatric disorders including alcohol use disorder (AUD). Like its role in regulating peripheral immune cells, calcineurin (CN) plays an integral role in processes regulating neuroimmune function and neuroinflammatory processes. Targeting CN or elements of its signaling pathways at critical points may aid in the functional recovery from neuroinflammatory related disorders. In this review we will highlight the role of neuroinflammation and calcineurin signaling in AUD, TBI and stress-induced disorders and discuss recent findings demonstrating a therapeutic effect of immunosuppressant-induced calcineurin inhibition in a pre-clinical model of binge alcohol drinking.

Central Administration of Cyclosporine A Decreases Ethanol Drinking.

AIMS: Abstinence among alcohol dependent liver graft recipients is remarkably high. The routine use of anti-immune agents in these patients led to rodent studies showing that immunosuppressants acting through inhibition of calcineurin (CLN) are highly effective in decreasing alcohol consumption. It remained unclear, however, whether the decreased alcohol consumption in rodent models is mediated through peripheral suppression of immune response or centrally through direct inhibition of cyclophilin-CLN in the brain. We tested the hypothesis that direct brain inhibition of CLN with intracerebroventricular (ICV) injections of the immunosuppressant cyclosporine A (CsA) is sufficient to decrease ethanol consumption in a rodent model of binge-like drinking. METHODS: Male C57BL/6NHsd mice were put through a modified 'drinking in the dark' (DID) paradigm. Effects of both peripheral (IP) and central (ICV) injections of CsA on ethanol consumption were assessed. RESULTS: Here, as in earlier work, IP CsA administration significantly decreased alcohol consumption. Supporting our hypothesis, central administration of CsA was sufficient to decrease alcohol consumption in a dose-dependent manner. There was no significant effect of CsA on water or sucrose consumption. CONCLUSIONS: These results clearly implicate a CLN-mediated mechanism in brain in the inhibitory effects of CsA on ethanol consumption and provide novel targets for investigation of treatment for Alcohol Use Disorders (AUD). These results also add to the growing body of literature implicating neuroimmune mechanisms in the etiology, pathophysiology and behaviors driving AUD. SHORT SUMMARY: The unusually high abstinence rate and routine use of immunosuppressants in AUD liver graft recipients led us to rodent studies showing that immunosuppressants acting through inhibition of calcineurin (CLN) are highly effective in decreasing drinking. Here we demonstrate that this effect is mediated by brain rather than peripheral immune mechanisms.

Late Reduction of Cocaine Cravings in a Randomized, Double-Blind Trial of Aripiprazole vs Perphenazine in Schizophrenia and Comorbid Cocaine Dependence.

PURPOSE: Co-occurring schizophrenia spectrum disorder and International Statistical Classification of Diseases, 10th Revision cocaine dependence present a particularly destructive constellation that is often difficult to treat. Both conditions raise dopamine transmission effects in the brain. Traditional neuroleptics block dopamine receptors, whereas aripiprazole modulates dopamine activity as an agonist/antagonist. We tested whether dopamine modulation is superior to dopamine blocking in dual-diagnosis patients. METHODS: In a randomized, double-blind, comparison design, cocaine-dependent schizophrenic subjects actively using cocaine received either aripiprazole or perphenazine in an 8-week trial. Primary outcome targeted cocaine-free urine sample proportions, whereas cocaine craving scores were a secondary variable. RESULTS: Subjects (N = 44) randomized (n = 22 per group) did not differ at baseline. The proportion of cocaine-free urine samples did not differ by medication group. Contrasting weeks 3 to 5 vs 6 to 8 revealed significant late reductions in craving with aripiprazole. On the respective 5-point subscales, craving intensity decreased by 1.53 ± 0.43 (P < 0.0005) points, craving frequency by 1.4 ± 0.40 (P > 0.0004) points, and craving duration by 1.76 ± 0.44 (P > 0.0001) points. CONCLUSIONS: A drug effect of aripiprazole on craving items appeared at week 6 of treatment, on average, and was not seen before that length of drug exposure. The data suggest that dopamine modulation reduces cocaine cravings but requires an acclimation period. To understand the mechanism of action better, a trial of depot aripiprazole may be useful. Clinically, a reduction in craving potentially offers a clearer focus for ongoing behavioral treatment. It may also offer a longer-term treatment effect with respect to the severity of relapse.

Anxious behavior induces elevated hippocampal Cb2 receptor gene expression.

Anxiety is differentially expressed across a continuum of stressful/fearful intensity, influenced by endocannabinoid systems and receptors. The hippocampus plays important roles in the regulation of affective behavior, emotion, and anxiety, as well as memory. Location of Cb1/Cb2 receptor action could be important in determining emotional valence, because while the dorsal hippocampus is involved in spatial memory and cognition, the ventral hippocampus has projections to the PFC, BNST, amygdala, and HPA axis, and is important for emotional responses to stress. During repeated social defeat in a Stress-Alternatives Model arena (SAM; an oval open field with escape portals only large enough for smaller mice), smaller C57BL6/N mice are subject to fear conditioning (tone=CS), and attacked by novel larger aggressive CD1 mice (US) over four daily (5min) trials. Each SAM trial presents an opportunity for escape or submission, with stable behavioral responses established by the second day of interaction. Additional groups had access to a running wheel. Social aggression plus fear conditioning stimulates enhanced Cb2 receptor gene expression in the dorsal CA1, dorsal and ventral dentate gyrus subregions in animals displaying a submissive behavioral phenotype. Escape behavior is associated with reduced Cb2 expression in the dorsal CA1 region, with freezing and escape latency correlated with mRNA levels. Escaping and submitting animals with access to running wheels had increased Cb2 mRNA in dorsal DG/CA1. These results suggest that the Cb2 receptor system is rapidly induced during anxiogenic social interactions plus fear conditioning or exercise; with responses potentially adaptive for coping mechanisms.

Molecular Mechanisms of Cannabis Signaling in the Brain.

Cannabis has been cultivated and used by humans for thousands of years. Research for decades was focused on understanding the mechanisms of an illegal/addictive drug. This led to the discovery of the vast endocannabinoid system. Research has now shifted to understanding fundamental biological questions related to one of the most widespread signaling systems in both the brain and the body. Our understanding of cannabinoid signaling has advanced significantly in the last two decades. In this review, we discuss the state of knowledge on mechanisms of Cannabis signaling in the brain and the modulation of key brain neurotransmitter systems involved in both brain reward/addiction and psychiatric disorders. It is highly probable that various cannabinoids will be found to be efficacious in the treatment of a number of psychiatric disorders. However, while there is clearly much potential, marijuana has not been properly vetted by the medical-scientific evaluation process and there are clearly a range of potentially adverse side-effects-including addiction. We are at crossroads for research on endocannabinoid function and therapeutics (including the use of exogenous treatments such as Cannabis). With over 100 cannabinoid constituents, the majority of which have not been studied, there is much Cannabis research yet to be done. With more states legalizing both the medicinal and recreational use of marijuana the rigorous scientific investigation into cannabinoid signaling is imperative.

Intensity of anxiety is modified via complex integrative stress circuitries.

Escalation of anxious behavior while environmentally and socially relevant contextual events amplify the intensity of emotional response produces a testable gradient of anxiety shaped by integrative circuitries. Apprehension of the Stress-Alternatives Model apparatus (SAM) oval open field (OF) is measured by the active latency to escape, and is delayed by unfamiliarity with the passageway. Familiar OF escape is the least anxious behavior along the continuum, which can be reduced by anxiolytics such as icv neuropeptide S (NPS). Social aggression increases anxiousness in the SAM, reducing the number of mice willing to escape by 50%. The apprehension accompanying escape during social aggression is diminished by anxiolytics, such as exercise and corticotropin releasing-factor receptor 1 (CRF1) antagonism, but exacerbated by anxiogenic treatment, like antagonism of α2-adrenoreceptors. What is more, the anxiolytic CRF1 and anxiogenic α2-adrenoreceptor antagonists also modify behavioral phenotypes, with CRF1 antagonism allowing escape by previously submissive animals, and α2-adrenoreceptor antagonism hindering escape in mice that previously engaged in it. Gene expression of NPS and brain-derived neurotrophic factor (BDNF) in the central amygdala (CeA), as well as corticosterone secretion, increased concomitantly with the escalating anxious content of the mouse-specific anxiety continuum. The general trend of CeA NPS and BDNF expression suggested that NPS production was promoted by increasing anxiousness, and that BDNF synthesis was associated with learning about ever-more anxious conditions. The intensity gradient for anxious behavior resulting from varying contextual conditions may yield an improved conceptualization of the complexity of mechanisms producing the natural continuum of human anxious conditions, and potential therapies that arise therefrom.

Recovering glycoside hydrolase genes from active tundra cellulolytic bacteria.

Bacteria responsible for cellulose hydrolysis in situ are poorly understood, largely because of the relatively recent development of cultivation-independent methods for their detection and characterization. This study combined DNA stable-isotope probing (DNA-SIP) and metagenomics for identifying active bacterial communities that assimilated carbon from glucose and cellulose in Arctic tundra microcosms. Following DNA-SIP, bacterial fingerprint analysis of gradient fractions confirmed isotopic enrichment. Sequenced fingerprint bands and clone library analysis of 16S rRNA genes identified active bacterial taxa associated with cellulose-associated labelled DNA, including Bacteroidetes (Sphingobacteriales), Betaproteobacteria (Burkholderiales), Alphaproteobacteria (Caulobacteraceae), and Chloroflexi (Anaerolineaceae). We also compared glycoside hydrolase metagenomic profiles from bulk soil and heavy DNA recovered from DNA-SIP incubations. Active populations consuming [(13)C]glucose and [(13)C]cellulose were distinct, based on ordinations of light and heavy DNA. Metagenomic analysis demonstrated a ∼3-fold increase in the relative abundance of glycoside hydrolases in DNA-SIP libraries over bulk-soil libraries. The data also indicate that multiple displacement amplification introduced bias into the resulting metagenomic analysis. This research identified DNA-SIP incubation conditions for glucose and cellulose that were suitable for Arctic tundra soil and confirmed that DNA-SIP enrichment can increase target gene frequencies in metagenomic libraries.