Disengagement of somatostatin neurons from lateral septum circuitry by oxytocin and vasopressin restores social-fear extinction and suppresses aggression outbursts in Prader-Willi syndrome model.

Background: Responding to social signals by expressing the correct behavior is not only challenged in autism, but also in diseases with high prevalence of autism, like Prader-Willi Syndrome (PWS). Clinical evidence suggests aberrant pro-social behavior in patients can be regulated by intranasal oxytocin (OXT) or vasopressin (AVP). However, what neuronal mechanisms underlie impaired behavioral responses in a socially-aversive context, and how can they be corrected, remains largely unknown. Methods: Using the Magel2 knocked-out (KO) mouse model of PWS (crossed with CRE-dependent transgenic lines), we devised optogenetic, physiological and pharmacological strategies in a social-fear-conditioning paradigm. Pathway specific roles of OXT and AVP signaling were investigated converging on the lateral septum (LS), a region which receives dense hypothalamic inputs. Results: OXT and AVP signaling promoted inhibitory synaptic transmission in the LS, which failure in Magel2KO mice disinhibited somatostatin (SST) neurons and disrupted social-fear extinction. The source of OXT and AVP deficits mapped specifically in the supraoptic nucleus→LS pathway of Magel2KO mice disrupting social-fear extinction, which could be corrected by optogenetic or pharmacological inhibition of SST-neurons in the LS. Interestingly, LS SST-neurons also gated the expression of aggressive behavior, possibly as part of functional units operating beyond local septal circuits. Conclusions: SST cells in the LS play a crucial role in integration and expression of disrupted neuropeptide signals in autism, thereby altering the balance in expression of safety versus fear. Our results uncover novel mechanisms underlying dysfunction in a socially-aversive context, and provides a new framework for future treatments in autism-spectrum disorders.

Associations of the immune system in aggression traits and the role of microglia as mediators.

There is an important relationship between the immune system and aggressive behavior. Aggressive encounters acutely increase the levels of proinflammatory cytokines, and there are positive correlations between aggressive traits and peripheral proinflammatory cytokines. Endotoxin lipopolysaccharide (LPS) treatment, which results in peripheral immune activation, decreases aggressive behavior as one of the sickness behavioral symptoms. In contrast, certain brain infections and chronic interferon treatment are associated with increased aggression. Indeed, the effects of proinflammatory cytokines on the brain in aggressive behavior are bidirectional, depending on the type and dose of cytokine, target brain region, and type of aggression. Some studies have suggested that microglial activation and neuroinflammation influence intermale aggression in rodent models. In addition, pathological conditions as well as physiological levels of cytokines produced by microglia play an important role in social and aggressive behavior in adult animals. Furthermore, microglial function in early development is necessary for the establishment of the social brain and the expression of juvenile social behaviors, including play fighting. Overall, this review discusses the important link between the immune system and aggressive traits and the role of microglia as mediators of this link.

Recognizing the opponent: The consolidation of long-term social memory in zebrafish males.

Recognizing and remembering another individual in a social context could be beneficial for individual fitness. Especially in agonistic encounters, remembering an opponent and the previous fight could allow for avoiding new conflicts. Considering this, we hypothesized that this type of social interaction forms a long-term recognition memory lasting several days. It has been shown that a second encounter 24 h later between the same pair of zebrafish males is resolved with lower levels of aggression. Here, we evaluated if this behavioral change could last for longer intervals and a putative mechanism associated with memory storage: the recruitment of NMDA receptors. We found that if a pair of zebrafish males fight and fight again 48 or 72 h later, they resolve the second encounter with lower levels of aggression. However, if opponents were exposed to MK-801 (NMDA receptor antagonist) immediately after the first encounter, they solved the second one with the same levels of aggression: that is, no reduction in aggressive behaviors was observed. These amnesic effect suggest the formation of a long-term social memory related to recognizing a particular opponent and/or the outcome and features of a previous fight.

Chronic ingestion of soy peptide supplementation reduces aggressive behavior and abnormal fear memory caused by juvenile social isolation.

Juvenile loneliness is a risk factor for psychopathology in later life. Deprivation of early social experience due to peer rejection has a detrimental impact on emotional and cognitive brain function in adulthood. Accumulating evidence indicates that soy peptides have many positive effects on higher brain function in rodents and humans. However, the effects of soy peptide use on juvenile social isolation are unknown. Here, we demonstrated that soy peptides reduced the deterioration of behavioral and cellular functions resulting from juvenile socially-isolated rearing. We found that prolonged social isolation post-weaning in male C57BL/6J mice resulted in higher aggression and impulsivity and fear memory deficits at 7 weeks of age, and that these behavioral abnormalities, except impulsivity, were mitigated by ingestion of soy peptides. Furthermore, we found that daily intake of soy peptides caused upregulation of postsynaptic density 95 in the medial prefrontal cortex and phosphorylation of the cyclic adenosine monophosphate response element binding protein in the hippocampus of socially isolated mice, increased phosphorylation of the adenosine monophosphate-activated protein kinase in the hippocampus, and altered the microbiota composition. These results suggest that soy peptides have protective effects against juvenile social isolation-induced behavioral deficits via synaptic maturation and cellular functionalization.

Chemical cousins with contrasting behavioural profiles: MDMA users and methamphetamine users differ in social-cognitive functions and aggression.

Methamphetamine (METH, "Crystal Meth") and 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") share structural-chemical similarities but have distinct psychotropic profiles due to specific neurochemical actions. Previous research has suggested that their impact on social cognitive functions and social behaviour may differ significantly, however, direct comparisons of METH and MDMA users regarding social cognition and interaction are lacking. Performances in cognitive and emotional empathy (Multifaceted Empathy Test) and emotion sensitivity (Face Morphing Task), as well as aggressive social behaviour (Competitive Reaction Time Task) were assessed in samples of n = 40 chronic METH users, n = 39 chronic MDMA users and n = 86 stimulant-naïve controls (total N = 165). Self-reports and hair samples were used to obtain subjective and objective estimates of substance use patterns. METH users displayed diminished cognitive and emotional empathy towards positive stimuli, elevated punitive social behaviour regardless of provocation, and self-reported heightened trait anger relative to controls. MDMA users diverged from the control group only by exhibiting a distinct rise in punitive behaviour when faced with provocation. Correlation analyses indicated that both higher hair concentrations of MDMA and METH may be associated with reduced cognitive empathy. Moreover, greater lifetime MDMA use correlated with increased punitive behaviour among MDMA users. Our findings confirm elevated aggression and empathy deficits in chronic METH users, while chronic MDMA users only displayed more impulsive aggression. Dose-response correlations indicate that some of these deficits might be a consequence of use. Specifically, the dopaminergic mechanism of METH might be responsible for social-cognitive deficits.

Effects of cariprazine on reducing symptoms of irritability, hostility, and agitation in patients with manic or mixed episodes of bipolar I disorder.

BACKGROUND: Hostility, irritability, and agitation are common in patients with bipolar I disorder. Post hoc analyses evaluated the effect of cariprazine on these symptoms in patients with bipolar I mania. METHODS: Data were pooled from three randomized, double-blind, placebo-controlled phase 3 cariprazine trials in adults with bipolar I manic/mixed episodes (NCT00488618, NCT01058096, NCT01058668); pooled cariprazine doses (3-12 mg/d) were analyzed. Patients were categorized into hostility/irritability and agitation subgroups by baseline scores: Young Mania Rating Scale (YMRS) irritability and disruptive-aggressive behavior items score ≥ 2; Positive and Negative Syndrome Scale (PANSS) hostility item ≥ 2; PANSS-Excited Component (PANSS-EC) total score ≥ 14 and score ≥ 4 on ≥ 1 individual item. Changes from baseline to week 3 in hostility/irritability- and agitation-related outcomes were evaluated. Adjustments were made for the presence of other manic symptoms, sedation, and akathisia. RESULTS: Most patients met subgroup inclusion criteria (YMRS hostility = 930; PANSS hostility = 841, PANSS-EC agitation = 486). In the YMRS subgroup, least squares mean differences in change from baseline were statistically significant for cariprazine versus placebo on YMRS hostility/irritability-related items (irritability [-0.93], disruptive-aggressive behavior [-0.79], combined [-1.75]; P ≤ 0.001 each), YMRS total score (-5.92, P ≤ 0.0001), and all individual YMRS items (-0.25 to -0.93, P ≤ 0.0001); differences remained significant after adjustment for other manic symptoms, sedation, and akathisia. Differences in PANSS hostility and PANSS-EC subgroups were significant for cariprazine versus placebo (P ≤ 0.001). LIMITATIONS: Post hoc analysis. CONCLUSION: Cariprazine demonstrated specific antihostility/irritability and anti-agitation effects in patients with manic/mixed episodes of bipolar I disorder and baseline hostility, irritability, or agitation.

Single administration of a psychedelic [(R)-DOI] influences coping strategies to an escapable social stress.

Psychedelic compounds have potentially rapid, long-lasting anxiolytic, antidepressive and anti-inflammatory effects. We investigated whether the psychedelic compound (R)-2,5-dimethoxy-4-iodoamphetamine [(R)-DOI], a selective 5-HT2A receptor partial agonist, decreases stress-related behavior in male mice exposed to repeated social aggression. Additionally, we explored the likelihood that these behavioral changes are related to anti-inflammatory properties of [(R)-DOI]. Animals were subjected to the Stress Alternatives Model (SAM), an escapable social stress paradigm in which animals develop reactive coping strategies - remaining in the SAM arena (Stay) with a social aggressor, or dynamically initiated stress coping strategies that involve utilizing the escape holes (Escape) to avoid aggression. Mice expressing these behavioral phenotypes display behaviors like those in other social aggression models that separate animals into stress-vulnerable (as for Stay) or stress-resilient (as for Escape) groups, which have been shown to have distinct inflammatory responses to social stress. These results show that Stay animals have heightened cytokine gene expression, and both Stay and Escape mice exhibit plasma and neural concentrations of the inflammatory cytokine tumor necrosis factor-α (TNFα) compared to unstressed control mice. Additionally, these results suggest that a single administration of (R)-DOI to Stay animals in low doses, can increase stress coping strategies such as increasing attention to the escape route, promoting escape behavior, and reducing freezing during socially aggressive interaction in the SAM. Lower single doses of (R)-DOI, in addition to shifting behavior to suggest anxiolytic effects, also concomitantly reduce plasma and limbic brain levels of the inflammatory cytokine TNFα.

Systemic histone deacetylase inhibition ameliorates the aberrant responses to acute stress in socially isolated male mice.

Adverse experiences in early life can induce maladaptive responses to acute stress in later life. Chronic social isolation during adolescence is an early life adversity that can precipitate stress-related psychiatric disorders. We found that male mice after 8 weeks of adolescent social isolation (SI) have markedly increased aggression after being exposed to 2 h of restraint stress (RS), which was accompanied by a significant increase of AMPA receptor- and NMDA receptor-mediated synaptic transmission in prefrontal cortex (PFC) pyramidal neurons of SIRS males. Compared to group-housed counterparts, SIRS males exhibited a significantly decreased level of histone H3 acetylation in PFC. Systemic administration of class I histone deacetylase inhibitors, romidepsin or MS-275, ameliorated the aggressive behaviour, as well as general social interaction deficits, of SIRS males. Electrophysiological recordings also found normalization of PFC glutamatergic currents by romidepsin treatment of SIRS male mice. These results revealed an epigenetic mechanism and intervention avenue for aggression induced by chronic social isolation. KEY POINTS: Adolescent chronic social isolation can precipitate stress-related psychiatric disorders. A significant increase of glutamatergic transmission is found in the prefrontal cortex (PFC) of socially isolated male mice exposed to an acute stress (SIRS). Treatment with class I histone deacetylase (HDAC) inhibitors ameliorates the aggressive behaviour and social interaction deficits of SIRS males, and normalizes glutamatergic currents in PFC neurons. It provides an epigenetic mechanism and intervention avenue for aberrant stress responses induced by chronic social isolation.

Real-World Evidence of Antipsychotic Monotherapy Versus Polypharmacy in the Treatment of Schizophrenia Spectrum Disorders.

PURPOSE/BACKGROUND: It is still not well known whether antipsychotic monotherapy versus polypharmacy differs in terms of efficacy in the emergency department (ED) utilization, presentation with agitation/aggression, and rehospitalization in schizophrenia spectrum disorders (SSD) patients. This study aimed to determine the effectiveness of antipsychotic monotherapy and polypharmacy for these outcomes in the real world. METHODS/PROCEDURES: The study was conducted with electronic health records of 669 SSD patients admitted to the ED. Patients were evaluated in 4 groups according to antipsychotic use at the first admission to ED: antipsychotic noncompliance for more than 90 days, antipsychotic noncompliance for 15 to 90 days, antipsychotic monotherapy, and polypharmacy. All patients followed up for at least 1 year after index admission. The primary outcomes determined an association between antipsychotic monotherapy versus polypharmacy and all-cause psychiatric hospitalization between the groups after index admission in the SSD. FINDINGS/RESULTS: The groups, including patients with antipsychotic noncompliance, had higher ED visits, more hospitalizations, and more admissions with agitation/aggression compared with antipsychotic monotherapy or polypharmacy. However, no differences were found between monotherapy and polypharmacy groups regarding these outcomes. In addition, there was no difference in the risk of hospitalization in monotherapy antipsychotic users compared with polypharmacy users. Patients discharged with monotherapy or polypharmacy also had similar rehospitalization rates at follow-up. IMPLICATIONS/CONCLUSIONS: There is no positive evidence that recommending polypharmacy over antipsychotic monotherapy is superior with regard to the resulting frequency of ED visits, ED admissions with agitation/aggression, hospitalization, and rehospitalization. In this context, antipsychotic monotherapy may be preferred over polypharmacy in patients who are not resistant to treatment.

Effectiveness and Safety of Intravenous Medications for the Management of Acute Disturbance (Agitation and Other Escalating Behaviors): A Systematic Review of Prospective Interventional Studies.

Acute disturbance is a broad term referring to escalating behaviors secondary to a change in mental state, such as agitation, aggression, and violence. Available management options include de-escalation techniques and rapid tranquilization, mostly via parenteral formulations of medication. While the intramuscular route has been extensively studied in a range of clinical settings, the same cannot be said for intravenous (IV); this is despite potential benefits, including rapid absorption and complete bioavailability. This systematic review analyzed existing evidence for effectiveness and safety of IV medication for management of acute disturbances. It followed a preregistered protocol (PROSPERO identification CRD42020216456) and is reported following the guidelines set by Preferred Reporting Items for Systematic Review and Meta-Analysis. APA PsycINFO, MEDLINE, and EMBASE databases were searched for eligible interventional studies up until May 30th, 2023. Data analysis was limited to narrative synthesis since primary outcome measures varied significantly. Results showed mixed but positive results for the effectiveness of IV dexmedetomidine, lorazepam, droperidol, and olanzapine. Evidence was more limited for IV haloperidol, ketamine, midazolam, chlorpromazine, and valproate. There was no eligible data on the use of IV clonazepam, clonidine, diazepam, diphenhydramine, propranolol, ziprasidone, fluphenazine, carbamazepine, or promethazine. Most studies reported favorable adverse event profiles, though they are unlikely to have been sufficiently powered to pick up rare serious events. In most cases, evidence was of low or mixed quality, accentuating the need for further standardized, large-scale, multi-arm randomized controlled trials with homogeneous outcome measures. Overall, this review suggests that IV medications may offer an effective alternative parenteral route of administration in acute disturbance, particularly in general hospital settings.

A systematic review of clozapine for aggression and violence in patients with schizophrenia or schizoaffective disorder.

Although uncommon, the risk of aggression and violence is greater in people with schizophrenia than in the general population. Clozapine is the "gold standard" pharmacologic treatment for the management of persistent agitation and aggression in people with schizophrenia and is consistently recommended by guidelines and reviews for this purpose. Although clozapine is indicated for treatment-resistant schizophrenia based on its superior efficacy, studies have proposed that clozapine may have specific properties that ameliorate aggression and hostility that are distinct from its antipsychotic effects. A literature review was conducted on June 3, 2023, using the US National Library of Medicine's PubMed resource to identify articles focusing on clozapine for the treatment of aggression, violence, and/or hostility in patients with schizophrenia or schizoaffective disorder. The majority of evidence, including from randomized control trials, supports the utilization of clozapine as maintenance treatment for persistent aggressive behavior in patients with schizophrenia, and supports that its anti-aggressive effects may be independent from its antipsychotic properties (e.g. - treatment of hallucinations and delusions). Future randomized control studies evaluating clozapine and clozapine serum levels with aggression as the primary outcome would be of benefit.

On an association between fear-induced aggression and striatal-enriched protein tyrosine phosphatase (STEP) in the brain of Norway rats.

Striatal-enriched protein tyrosine phosphatase (STEP) is a signal transduction protein involved in the pathogenesis of neuropathologies. A STEP inhibitor (TC-2153) has antipsychotic and antidepressant effects. Here, we evaluated the role of STEP in fear-induced aggression using Norway rats selectively bred for 90 generations for either high aggression toward humans (aggressive rats) or its absence (tame rats). We studied the effects of acute administration of TC-2153 on behavior and STEP expression in the brain of these animals and the influence of chronic treatment with TC-2153 on the behavior and STEP expression in aggressive rats in comparison with classic antidepressant fluoxetine, which is known to exert antiaggressive action. Acute TC-2153 administration decreased the aggressive reaction to humans in aggressive rats, while having no impact on the friendly behavior of tame rats. Moreover, in the elevated plus-maze test, the drug had an anxiolytic effect on both aggressive and tame rats. Aggressive rats demonstrated elevated levels of a STEP isoform (STEP46) as compared to tame animals, whereas acute TC-2153 administration significantly reduced STEP46 protein concentration in the brain of aggressive rats. Chronic treatment of aggressive rats with either TC-2153 or fluoxetine attenuated fear-induced aggression. Chronic administration of fluoxetine enhanced the exploratory activity in the elevated plus-maze test and decreased the STEP46 protein level in aggressive rats' hippocampus, whereas chronic TC-2153 administration did not affect these parameters. Thus, STEP46 can play an important role in the mechanisms of aggression and may mediate antiaggressive effects of TC-2153 and fluoxetine.

Inhibition of boldenone-induced aggression in rats by curcumin: Targeting TLR4/MyD88/TRAF-6/NF-κB pathway.

The illicit abuse of anabolic steroids is associated with brutal aggression, which represents a serious health hazard and social threat. Boldenone is commonly used for doping by athletes and adolescents for esthetic purposes and to enhance performance and endurance during competitions. However, the mechanistic pathways underlying boldenone-induced behavioral deviations and neuronal toxicity have not yet been elucidated. On the other hand, the natural polyphenol curcumin is appreciated for its relative safety, potent antioxidant activity, and anti-inflammatory properties. Therefore, the present study was initiated to explore the signaling pathways underlying boldenone-induced anxiety and aggression in rats, and the protective effects of curcumin. To achieve this aim, male Wistar albino rats were randomly distributed into control, curcumin (100 mg/kg in sesame oil, p.o., once daily), boldenone (5 mg/kg, intramuscular, once weekly), and combination groups. Rats were challenged across the open field, irritability, defensive aggression, and resident-intruder tests. The prefrontal cortex was used to assess serotonin level, oxidative stress markers, and mRNA expression of myeloid differentiation primary response gene (MyD88), TNFR-associated factor 6 (TRAF-6), tumor necrosis factor α (TNF-α), interleukin-1ß (IL-1ß), protein expression of toll-like receptor 4 (TLR4), and phosphorylated nuclear factor-κB transcription factor (NF-κB p65). Unprecedented, the current results showed that boldenone elicited aggression in rats accompanied by depleted serotonin, enhanced oxidative stress, and exaggerated inflammatory response via upregulation of TLR4/MyD88/TRAF-6/NF-κB pathway. Interestingly, curcumin mitigated boldenone-induced neurobehavioral disturbances in rats, normalized the oxidant/antioxidant balance, and suppressed TLR4/MyD88/TRAF-6/NF-κB pathway and its downstream proinflammatory signaling molecules TNF-α and IL-1ß.

Estrogen signaling modulates behavioral selection toward pups and amygdalohippocampal area in the rhomboid nucleus of the bed nucleus of the stria terminalis circuit.

Gonadal steroid hormone influences behavioral choice of adult animals toward pups, parental or aggressive. We previously reported that long-term administration of 17ß-estradiol (E2) to male mice during sexual maturation induces aggressive behavior toward conspecific pups, which is called "infanticide," and significantly enhanced excitatory synaptic transmission in the rhomboid nucleus of bed nucleus of the stria terminalis (BSTrh), which is an important brain region for infanticide. However, it is unclear how estrogen receptor-dependent signaling after sexual maturity regulates neural circuits including the BSTrh. Here we revealed that E2 administration to gonadectomized mice in adulthood elicited infanticidal behavior and enhanced excitatory synaptic transmission in the BSTrh by increasing the probability of glutamate release from the presynaptic terminalis. Next, we performed whole-brain mapping of E2-sensitive brain regions projecting to the BSTrh and found that amygdalohippocampal area (AHi) neurons that project to the BSTrh densely express estrogen receptor 1 (Esr1). Moreover, E2 treatment enhanced synaptic connectivity in the AHi-BSTrh pathway. Together, these results suggest that reinforcement of excitatory inputs from AHi neurons into the BSTrh by estrogen receptor-dependent signaling may contribute to the expression of infanticide.

Eventos adversos em uma unidade de internação psiquiátrica / Eventos adversos en una unidad de hospitalización psiquiátrica / Adverse events in a psychiatric hospitalization unit

RESUMO Objetivo descrever os eventos adversos presentes na internação psiquiátrica, analisando-os à luz da teoria do erro humano. Método pesquisa qualitativa, realizada em 2018 em um hospital psiquiátrico. Os dados foram coletados por entrevistas semiestruturadas com 15 profissionais de saúde da equipe multidisciplinar. A análise foi lexical por meio do software Alceste. Resultados evidenciaram-se eventos adversos medicamentosos por erros de administração ou por reações adversas a medicamentos, que produzem danos como impregnação, reações extrapiramidais associadas aos riscos de queda e broncoaspiração pela sonolência e/ou sedação. Outros danos relacionam-se à agressividade do paciente, que produz lesões corporais a si ou a outro, como durante uma tentativa de suicídio ou uso de violência como comportamento de fuga ou defesa. Considerações finais e implicações para a prática existem eventos adversos mais comuns nos ambientes de internação psiquiátrica que precisam ser de conhecimento da equipe de saúde mental porque demandam ações de mitigação por meio do fortalecimento dos sistemas de segurança do paciente. Os dados subsidiam ações para o fortalecimento dos sistemas de segurança nos ambientes de internação psiquiátrica e contribuem à reflexão do conceito de segurança do paciente na psiquiatria.

RESUMEN Objetivo describir los eventos adversos presentes en la hospitalización psiquiátrica, analizándolos a la luz de la teoría del error humano. Método investigación cualitativa, realizada en 2018 en un hospital psiquiátrico. Los datos se recolectaron a través de entrevistas semiestructuradas con 15 profesionales de la salud del equipo multidisciplinario. Se llevó a cabo el análisis léxico por medio del software Alceste. Resultados se evidenciaron eventos adversos por errores de administración o reacciones adversas al fármaco, que producen daños como impregnación y reacciones extrapiramidales asociadas al riesgo de caídas y broncoaspiración por somnolencia y / o sedación. Otros daños se relacionan con agresividad por parte del paciente, que produce daño corporal a sí mismo o a otro, como durante un intento de suicidio o uso de violencia como conducta de fuga o defensa. Conclusión e implicaciones para la práctica hay eventos adversos más comunes en entornos de hospitalización psiquiátrica que deben ser conocidos por el equipo de salud mental porque exigen acciones de mitigación a través del fortalecimiento de los sistemas de seguridad del paciente. Los datos reflejan la necesidad de implementar acciones para fortalecer los sistemas de seguridad en entornos de hospitalización psiquiátrica y contribuyen a la reflexión del concepto de seguridad del paciente en psiquiatría.

ABSTRACT Objective to describe the adverse events found in psychiatric hospitalization, analyzing them in the light of the human error theory. Method a qualitative research study, carried out in 2018 in a psychiatric hospital. The data were collected through semi-structured interviews with 15 health professionals from the multidisciplinary team. Analysis was of the lexical type using the Alceste software. Results adverse drug events were evidenced due to administration errors or adverse drug reactions, which produce harms such as impregnation and extrapyramidal reactions associated with the risks for falls and bronchoaspiration due to drowsiness and/or sedation. Other harms are related to the patient's aggressiveness, which produce bodily self-harm or harms to another person, such as during a suicide attempt or use of violence as an escape or defense behavior. Conclusion and implications for the practice some adverse events are more frequent in psychiatric hospitalization settings; such events need to be known by the mental health team, as they require mitigation actions through the strengthening of patient safety systems. The data subsidize actions for strengthening safety systems in psychiatric hospitalization settings and contribute to reflecting on the concept of patient safety in Psychiatry.

Effect of Central Administration of Brain-Derived Neurotrophic Factor (BDNF) on Behavior and Brain Monoamine Metabolism in New Recombinant Mouse Lines Differing by 5-HT1A Receptor Functionality.

Experiments were carried out on recombinant B6.CBA-D13Mit76C (B6-M76C) and B6.CBA-D13Mit76B (B6-M76B) mouse lines created by transferring a 102.73-118.83 Mbp fragment of chromosome 13, containing the 5-HT1A receptor gene, from CBA or C57BL/6 strains to a C57BL/6 genetic background, correspondingly. We have recently shown different levels of 5-HT1A receptor functionality in these mouse lines. The administration of BDNF (300 ng/mouse, i.c.v.) increased the levels of exploratory activity and intermale aggression only in B6-M76B mice, without affecting depressive-like behavior in both lines. In B6-M76B mice the behavioral alterations were accompanied by a decrease in the 5-HT2A receptor functional activity and the augmentation of levels of serotonin and its main metabolite, 5-HIAA (5-hydroxyindoleacetic acid), in the midbrain. Moreover, the levels of dopamine and its main metabolites, HVA (homovanillic acid) and DOPAC (3,4-dihydroxyphenylacetic acid), were also elevated in the striatum of B6-M76B mice after BDNF treatment. In B6-M76C mice, central BDNF administration led only to a reduction in the functional activity of the 5-HT1A receptor and a rise in DOPAC levels in the midbrain. The obtained data suggest the importance of the 102.73-118.83 Mbp fragment of mouse chromosome 13, which contains the 5-HT1A receptor gene, for BDNF-induced alterations in behavior and the brain monoamine system.

Acute cannabidiol treatment attenuates ethanol-induced place preference and reduces aggressivity in group-housed male rats.

Alcohol abuse is a widespread cause of aggressive and impulsive behaviors that impact the users as well as their entourage. However, only a few medications are effective. Recently, cannabidiol has been reported to improve mood disorders and recovery from substance abuse, yet the psychopharmacologic effects of cannabidiol in ethanol-induced drug reward and aggressivity remain unexplored. In the present study, we investigated the effects of cannabidiol on ethanol-induced place preference and aggressivity in individually and group-housed male rats using the conditioned place preference test, and intruder evoc aggression test, respectively. The obtained results showed that ethanol significantly increased locomotor activity, induced conditioned place preference in all animals, and, specifically, increased aggressivity in individually housed rats. These behavioural impairments induced by ethanol were associated with decreased glucocorticoid and mineralocorticoid receptors transcription in the prefrontal cortex. Notwithstanding, cannabidiol at a dose of 10 mg/kg significantly inhibited Et-OH-induced place preference in group-housed, but not in individually housed rats, and markedly inhibited the aggressive behaviour. These findings suggest that ethanol-induced behavioural impairments are dependent on the housing condition that may affect corticosterone receptors expression and subsequently the animal responsivity to cannabidiol treatment.

Pharmacological and philosophical considerations for the around-the-clock use of scheduled melatonin to promote sedation and reduce aggression in individuals with serious mental illness: a case report.

Melatonin, the endogenous hormone that helps maintain circadian rhythm, has been used exogenously for both primary and secondary sleep disorders. While the effects of melatonin given prior to planned sleep and to restore normal circadian sleep phases have been well studied, there is little information on the use of melatonin as a pharmacotherapeutic intervention for around-the-clock sedation to prevent agitation and aggressive patient behaviors. This is the first case report to our knowledge of melatonin used throughout the day, as a scheduled dose for prolonged treatment duration, to reduce aggression in a patient with severe mental illness.

Chemogenetic modulation of histaminergic neurons in the tuberomamillary nucleus alters territorial aggression and wakefulness.

Designer receptor activated by designer drugs (DREADDs) techniques are widely used to modulate the activities of specific neuronal populations during behavioural tasks. However, DREADDs-induced modulation of histaminergic neurons in the tuberomamillary nucleus (HATMN neurons) has produced inconsistent effects on the sleep-wake cycle, possibly due to the use of Hdc-Cre mice driving Cre recombinase and DREADDs activity outside the targeted region. Moreover, previous DREADDs studies have not examined locomotor activity and aggressive behaviours, which are also regulated by brain histamine levels. In the present study, we investigated the effects of HATMN activation and inhibition on the locomotor activity, aggressive behaviours and sleep-wake cycle of Hdc-Cre mice with minimal non-target expression of Cre-recombinase. Chemoactivation of HATMN moderately enhanced locomotor activity in a novel open field. Activation of HATMN neurons significantly enhanced aggressive behaviour in the resident-intruder test. Wakefulness was increased and non-rapid eye movement (NREM) sleep decreased for an hour by HATMN chemoactivation. Conversely HATMN chemoinhibition decreased wakefulness and increased NREM sleep for 6 h. These changes in wakefulness induced by HATMN modulation were related to the maintenance of vigilance state. These results indicate the influences of HATMN neurons on exploratory activity, territorial aggression, and wake maintenance.