Anxiety In Male Mice Research Articles

Sex-dependent effects of carbohydrate source and quantity on caspase-1 activity in the mouse central nervous system

BackgroundMounting evidence links glucose intolerance and diabetes as aspects of metabolic dysregulation that are associated with an increased risk of developing dementia. Inflammation and inflammasome activation have emerged as a potential link between these disparate pathologies. As diet is a key factor in both the development of metabolic disorders and inflammation, we hypothesize that long term changes in dietary factors can influence nervous system function by regulating inflammasome activity and that this phenotype would be sex-dependent, as sex hormones are known to regulate metabolism and immune processes.Methods5-week-old male and female transgenic mice expressing a caspase-1 bioluminescent reporter underwent cranial window surgeries and were fed control (65% complex carbohydrates, 15% fat), high glycemic index (65% carbohydrates from sucrose, 15% fat), or ketogenic (1% complex carbohydrates, 79% fat) diet from 6 to 26 weeks of age. Glucose regulation was assessed with a glucose tolerance test following a 4-h morning fast. Bioluminescence in the brain was quantified using IVIS in vivo imaging. Blood cytokine levels were measured using cytokine bead array. 16S ribosomal RNA gene amplicon sequencing of mouse feces was performed to assess alterations in the gut microbiome. Behavior associated with these dietary changes was also evaluated.ResultsThe ketogenic diet caused weight gain and glucose intolerance in both male and female mice. In male mice, the high glycemic diet led to increased caspase-1 biosensor activation over the course of the study, while in females the ketogenic diet drove an increase in biosensor activation compared to their respective controls. These changes correlated with an increase in inflammatory cytokines present in the serum of test mice and the emergence of anxiety-like behavior. The microbiome composition differed significantly between diets; however no significant link between diet, glucose tolerance, or caspase-1 signal was established.ConclusionsOur findings suggest that diet composition, specifically the source and quantity of carbohydrates, has sex-specific effects on inflammasome activation in the central nervous system and behavior. This phenotype manifested as increased anxiety in male mice, and future studies are needed to determine if this phenotype is linked to alterations in microbiome composition.

A molecularly defined amygdala-independent tetra-synaptic forebrain-to-hindbrain pathway for odor-driven innate fear and anxiety.

Fear-related disorders (for example, phobias and anxiety) cause a substantial public health problem. To date, studies of the neural basis of fear have mostly focused on the amygdala. Here we identify a molecularly defined amygdala-independent tetra-synaptic pathway for olfaction-evoked innate fear and anxiety in male mice. This pathway starts with inputs from the olfactory bulb mitral and tufted cells to pyramidal neurons in the dorsal peduncular cortex that in turn connect to cholecystokinin-expressing (Cck+) neurons in the superior part of lateral parabrachial nucleus, which project to tachykinin 1-expressing (Tac1+) neurons in the parasubthalamic nucleus. Notably, the identified pathway is specifically involved in odor-driven innate fear. Selective activation of this pathway induces innate fear, while its inhibition suppresses odor-driven innate fear. In addition, the pathway is both necessary and sufficient for stress-induced anxiety-like behaviors. These findings reveal a forebrain-to-hindbrain neural substrate for sensory-triggered fear and anxiety that bypasses the amygdala.

Adulthood bisphenol A exposure induces anxiety in male mice via downregulation of alpha-1D adrenergic receptor in paraventricular thalamus

Bisphenol A (BPA), a ubiquitous endocrine disrupting chemical, is widely used in household plastic products. Large amounts of evidence indicate prenatal and postnatal BPA exposure causes neurodevelopmental disorders such as anxiety and autism. However, the neuronal mechanisms underlying the neurotoxic effects of adulthood BPA exposure remain poorly understood. Here, we provided evidences that adult mice treated with BPA (0.45 mg/kg/day) during 3 weeks exhibited sex-specific anxiety like behaviors. We demonstrated that the BPA-induced anxiety in male mice, but not in female mice, was closely associated with hyperactivity of glutamatergic neurons in the paraventricular thalamus (PVT). Acute chemogenetic activation of PVT glutamatergic neurons caused similar effects on anxiety as observed in male mice exposed to BPA. In contrast, acute chemogenetic inhibition of PVT glutamatergic neurons reduced BPA-induced anxiety in male mice. Concomitantly, the BPA-induced anxiety was related with a down-regulation of alpha-1D adrenergic receptor in the PVT. Taken together, the present study indicated a previously unknown target region in the brain for neurotoxic effects of BPA on anxiety and implicated a possible molecular mechanism of action.

SIRT1 in the BNST modulates chronic stress-induced anxiety of male mice via FKBP5 and corticotropin-releasing factor signaling.

Although clinical reports have highlighted association of the deacetylase sirtuin 1 (SIRT1) gene with anxiety, its exact role in the pathogenesis of anxiety disorders remains unclear. The present study was designed to explore whether and how SIRT1 in the mouse bed nucleus of the stria terminalis (BNST), a key limbic hub region, regulates anxiety. In a chronic stress model to induce anxiety in male mice, we used site- and cell-type-specific in vivo and in vitro manipulations, protein analysis, electrophysiological and behavioral analysis, in vivo MiniScope calcium imaging and mass spectroscopy, to characterize possible mechanism underlying a novel anxiolytic role for SIRT1 in the BNST. Specifically, decreased SIRT1 in parallel with increased corticotropin-releasing factor (CRF) expression was found in the BNST of anxiety model mice, whereas pharmacological activation or local overexpression of SIRT1 in the BNST reversed chronic stress-induced anxiety-like behaviors, downregulated CRF upregulation, and normalized CRF neuronal hyperactivity. Mechanistically, SIRT1 enhanced glucocorticoid receptor (GR)-mediated CRF transcriptional repression through directly interacting with and deacetylating the GR co-chaperone FKBP5 to induce its dissociation from the GR, ultimately downregulating CRF. Together, this study unravels an important cellular and molecular mechanism highlighting an anxiolytic role for SIRT1 in the mouse BNST, which may open up new therapeutic avenues for treating stress-related anxiety disorders.

Preclinical effects of cannabidiol in an experimental model of migraine.

Migraine is a disabling disorder characterized by recurrent headaches, accompanied by abnormal sensory sensitivity and anxiety. Despite extensive historical use of cannabis in headache disorders, there is limited research on the nonpsychoactive cannabidiol (CBD) for migraine and there is no scientific evidence to prove that CBD is an effective treatment. The effects of CBD are examined here using a calcitonin gene-related peptide (CGRP)-induced migraine model that provides measures of cephalic allodynia, spontaneous pain, altered light sensitivity (photophobia), and anxiety-like behavior in C57BL/6J mice. A single administration of CGRP induced facial hypersensitivity in both female and male mice. Repeated CGRP treatment produced progressively decreased levels in basal thresholds of allodynia in females, but not in males. A single CBD administration protected both females and males from periorbital allodynia induced by a single CGRP injection. Repeated CBD administration prevented increased levels of basal allodynia induced by repeated CGRP treatment in female mice and did not lead to responses consistent with migraine headache as occurs with triptans. Cannabidiol, injected after CGRP, reversed CGRP-evoked allodynia. Cannabidiol also reduced spontaneous pain traits induced by CGRP administration in female mice. Finally, CBD blocked CGRP-induced anxiety in male mice, but failed in providing protection from CGRP-induced photophobia in females. These results demonstrate the efficacy of CBD in preventing episodic and chronic migraine-like states with reduced risk of causing medication overuse headache. Cannabidiol also shows potential as an abortive agent for treating migraine attacks and headache-related conditions such as spontaneous pain and anxiety.

Specific Inhibition of Interpeduncular Nucleus GABAergic Neurons Alleviates Anxiety-Like Behaviors in Male Mice after Prolonged Abstinence from Methamphetamine.

Anxiety is one of the most common withdrawal symptoms of methamphetamine (METH) abuse, which further drives relapse to drugs. Interpeduncular nucleus (IPN) has been implicated in anxiety-like behaviors and addiction, yet its role in METH-abstinence-induced anxiety remains unknown. Here, we found that prolonged abstinence from METH enhanced anxiety-like behaviors in male mice, accompanied by more excited IPN GABAergic neurons, as indicated by the increased c-fos expression and the enhanced neuronal excitability by electrophysiological recording in the GABAergic neurons. Using the designer receptors exclusively activated by designer drugs method, specific inhibition of IPN GABAergic neurons rescued the aberrant neuronal excitation of IPN GABAergic neurons and efficiently reduced anxiety-like behaviors, whereas it did not induce depression-like behaviors in male mice after prolonged abstinence from METH. These findings reveal that IPN GABAergic neurons should be a promising brain target to alleviate late withdrawal symptoms from METH with few side effects.SIGNIFICANCE STATEMENT Prolonged abstinence from METH triggers IPN GABAergic neurons and ultimately increases anxiety in male mice. Suppressing IPN GABAergic neurons rescues METH abstinence-induced aberrant neuronal excitation of IPN GABAergic neurons and efficiently reduces anxiety in mice.

The neurotoxic effect of lactational PFOS exposure on cerebellar functional development in male mice

Recent studies showed a possible association between perfluorooctane sulfonate (PFOS) and developmental disabilities. We previously found the specific effects of PFOS exposure on learning and memory, however, its effect on the other developmental disabilities such as motor and social deficits remains unclear. We examined the effect of early lactational PFOS exposure on motor coordination, social activity, and anxiety in male mice. We orally administered a PFOS solution to dams from postnatal day 1–14. At 10 weeks old, we conducted a behavior test battery to evaluate motor performance, social activity, and anxiety, followed by electrophysiology and Western blot analysis. PFOS-exposed mice displayed impaired motor coordination. Whole-cell patch-clamp recordings from Purkinje cells revealed that the short-term and long-term plasticity at parallel fiber-Purkinje cell synapses are affected by PFOS exposure. Western blot analysis indicated that PFOS exposure increased syntaxin binding protein 1 (Munc18-1) and glutamate metabotropic receptor 1 (mGluR1) protein levels, which may be associated with the change in neurotransmitter release from parallel fibers and the level of long-term depression, respectively. The present study demonstrates that lactational PFOS exposure may have disrupted the pre- and postsynaptic plasticity at parallel fiber-Purkinje cell synapses, causing profound, long-lasting abnormal effects on the cerebellar function.

NCK1 Regulates Amygdala Activity to Control Context-dependent Stress Responses and Anxiety in Male Mice

Anxiety disorder (AD) is characterized by the development of maladaptive neuronal circuits and changes to the excitatory/inhibitory (E/I) balance of the central nervous system. Although AD is considered to be heritable, specific genetic markers remain elusive. Recent genome-wide association studies (GWAS) studies have identified non-catalytic region of tyrosine kinase adaptor protein 1 (NCK1), a gene that codes for an intracellular adaptor protein involved in actin dynamics, as an important gene in the regulation of mood. Using a murine model in which NCK1 is inactivated, we show that male, but not female, mice display increased levels of context-dependent anxiety-like behaviors along with an increase in circulating serum corticosterone relative to control. Treatment of male NCK1 mutant mice with a positive allosteric modulator of the GABAA receptor rescued the anxiety-like behaviors implicating NCK1 in regulating neuronal excitability. These defects are not attributable to apparent defects in gross brain structure or in axon guidance. However, when challenged in an approach-avoidance conflict paradigm, male NCK1-deficient mice have decreased neuronal activation in the prefrontal cortex (PFC), as well as decreased activation of inhibitory interneurons in the basolateral amygdala (BLA). Finally, NCK1 deficiency results in loss of dendritic spine density in principal neurons of the BLA. Taken together, these data implicate NCK1 in the control of E/I balance in BLA. Our work identifies a novel role for NCK1 in the regulation of sex-specific neuronal circuitry necessary for controlling anxiety-like behaviors. Further, our work points to this animal model as a useful preclinical tool for the study of novel anxiolytics and its significance towards understanding sex differences in anxiolytic function.

Behavior of Adult 5-HT1A Receptor Knockout Mice Exposed to Stress During Prenatal Development

Chronic maternal stress during pregnancy can have long-term, detrimental consequences for the offspring. An understanding of the mechanisms responsible for mediating these effects is essential for devising therapeutic interventions. Here, we examined whether serotonin 1A receptor (5-HT1AR) mediates the effects of maternal stress on the behavioral outcomes of the offspring as adults. Heterozygous (HET) mouse dams were bred with HET males and were randomly assigned to stress or control groups. Pregnant dams in the stress group were exposed to a regime of chronic unpredictable stress from embryonic day 7 to 18. At two months of age, groups of male and female wildtype (WT), HET, and knockout (KO) offspring underwent a comprehensive behavioral test battery that included tests of social behavior, memory, aggression, anxiety, sensorimotor information processing, and exploratory and risk assessment behaviors. Independent of genotype, prenatal stress resulted in a change in locomotor activity and fear memory in male mice and a change in prepulse inhibition in female animals. 5-HT1AR KO affected anxiety in male mice, and fear memory and prepulse inhibition in female mice. 5-HT1AR genotype moderated the effects of maternal prenatal stress exposure on social behavior of male offspring and on activity levels of female offspring. Our findings indicate that 5-HT1A receptor availability can affect outcomes of the offspring resulting from maternal prenatal stress exposure, and that these effects are sex-specific.

Combination Effect of Methadone and Haloperidol on Morphine Withdrawal-Induced Anxiety in Male Mice

Combination Effect of Methadone and Haloperidol on Morphine Withdrawal-Induced Anxiety in Male Mice

Effect of <i>Citrus aurantium</i> L. Essential Oil and Its Interaction with Fluoxetine on Anxiety in Male Mice

Anxiety is a very common mental disorder among neurological diseases. Some herbs have soothing effects and play an important role in reducing anxiety. The purpose of this study is to investigate the effect of Citrus aurantium L. essential oil on anxiety and its interference with serotonergic pathway. Sixty male mice were assigned into control, sham (saline and olive oil), and experimental groups. Intraperitoneal injection of Citrus aurantium L. essential oil was applied at doses of 0.5, 2.5, and 5 percent for 5 days. In another set of experiments, after intraperitoneal injection of Citrus aurantium L. essential oil at doses of 0.5, 2.5, and 5 percent for 5 days, on the 5th day, 30 minutes before applying essential oil, fluoxetine (2 mg/kg) was injected. Then, the anxiety-related behavior was assessed using elevated plus maze test. The results revealed that injection of essential oil of Citrus aurantium L. alone or along with fluoxetine led to increasing the number of entries into the open arms and the time spent in open arms that was significantly different compared with control and sham groups (P ＜ 0.001). Besides, further effects revealed when fluoxetine added to essential oils, however no more effects obtained when compared to fluoxetine alone. It is concluded that Citrus aurantium L. essential oil can reduce the anxiety in male mice and due to fluoxetin potentiation and maximum response observed, the herb may express its anxiolytic effects in part, via serotonergic system.

Pro-aggressive effect of diazepam in male mice with repeated experience of aggression

Previous studies have reported that repeated experience of aggression is attended with the development of increased anxiety in male mice. The paper aimed to investigate effect of anxiolytic, diazepam, on the level of anxiety and aggression in these animals. The drug was chronically administrated for two weeks at the process of aggression experience acquisition. It was shown that diazepam decreased anxiety but didn't influence aggression level assessed by total time of attacks. However, diazepam decreased demonstration of aggressive grooming in part of aggressive males. Group of diazepam-treated aggressive males which displayed aggressive grooming didn't differ in level of anxiety and aggression in saline-treated male mice. Diazepam had anxiolytic and pro-aggressive effects in male mice without demonstrating aggressive grooming. Thus, we can conclude that anxiolytic effect of diazepam is accompanied with increased aggression as side effect in some male mice which have repeated experience of aggression.

P.6.d.001 Effects of 3,4-methylenedioxy-N-ethylamphetamine (MDEA) on anxiety in male mice tested in the elevated plus-maze

P.6.d.001 Effects of 3,4-methylenedioxy-N-ethylamphetamine (MDEA) on anxiety in male mice tested in the elevated plus-maze

On-ground housing in “Mice Drawer System” (MDS) cage affects locomotor behaviour but not anxiety in male mice

In the present study adult male mice were housed for 21 days in a housing modules of the Mice Drawer System (MDS). MDS is the facility that will support the research on board the International Space Station (ISS). Our investigation focused on: circadian rhythmicity of wide behavioural categories such as locomotor activity, food intake/drinking and resting; emotionality in the elevated plus maze (EPM); body weight. Housing in the MDS determined a strong up-regulation of activity and feeding behaviour and a concomitant decrease in inactivity. Importantly, housing in the MDS disrupted circadian rhythmicity in mice and also determined a decrease in body weight. Finally, when mice were tested in the EPM a clear hyperactivity (i.e. increased total transitions) was found, while no evidence for altered anxiety was detected. In conclusion, housing adult male mice in the MDS housing modules may affect their behaviour, circadian rhythmicity while having no effect on anxiety. It is suggested that to allow adaptation to the peculiar housing allowed by MDS a longer housing duration is needed.

Effects of Repeated Experience of Aggression on the Aggressive Motivation and Development of Anxiety in Male Mice

The sensory contact model allowed aggressive behavior to be formed in male mice as a result of repeated experience of victory in daily social confrontations. In individuals of the low aggressivity, high emotionality line CBA/Lac, repeated experience of aggression led to the development of anxiety, assessed in the elevated cross maze test. Males showed increases in aggressive motivation, measured in terms of increases in behavioral reactions to conspecifics in the partition test. It is concluded that repeated experience of aggression provokes the development of anxiety in male mice and that the level of developing anxiety, like its behavioral correlates, depends on the duration of aggressive experience and the mouse line studied.

Acute and subchronic effects of MDMA (“ecstasy”) on anxiety in male mice tested in the elevated plus-maze

3,4-Methylenedioxymethamphetamine (MDMA) is a compound structurally similar to methamphetamine, which has become one of the most widely used illicit substances. Animal studies investigating acute effects of MDMA on anxiety are unclear since, although an anxiogenic-like action of MDMA in different animal models of anxiety has been mainly described, there is also evidence supporting an anxiolytic-like effect for this drug. An attempt was made to clarify the possible anxiogenic-like profile of MDMA (1, 8 and 15 mg/kg ip) by analyzing its effect on behavior of male mice in the elevated plus-maze test. Moreover, the possible development of tolerance to the effects of MDMA on anxiety after its subchronic administration for 5 consecutive days was examined. The parameters evaluated included: (1) total time in open arms, (2) total time in closed arms, (3) total time in central area, (4) number of open arm entries, (5) number of closed arm entries and (6) number of central area entries. Acute treatment with MDMA (8 mg/kg) significantly reduced the time spent in the open arms, as well as markedly increasing the number of entries in the closed arms and in the central area, as compared with the control group, suggesting that MDMA, at this dose, has an anxiogenic-like activity. Mice subchronically treated with the drug (1 and 8 mg/kg) displayed a notable reduction in the time spent in the open arms, accompanied by an increase in the time spent in the closed arms and in the central platform. These results indicate that the anxiogenic-like effect found after acute treatment is not only maintained but also more marked after subchronic treatment. In contrast, mice treated subchronically with the highest dose of MDMA (15 mg/kg) exhibited a significant increase in the time spent in the open arms as well as a marked reduction in the time spent in the closed arms, supporting an anxiolytic-like activity of the drug. A possible dual pharmacological property of MDMA on anxiety is suggested.

Association between experience of aggression and anxiety in male mice

The sensory contact technique increases aggressiveness in male mice and allows an aggressive type of behavior to be formed as a result of repeated experience of social victories in daily agonistic confrontations. In the low aggressive and high emotional mice of CBA/Lac strain, repeated positive fighting experience leads to increased plus maze anxiety in the winners after 10 days of experience of victories and much more after 20 days. Behavioral reactivity to other conspecifics was significantly increased as revealed by the parameters of partition test, which measures aggressive motivation in the winners. Thus, anxiety as a consequence of repeated experience of aggression is associated with the increase of aggressive motivation in CBA/Lac mice. It is concluded, that: (1) Repeated experience of aggression provokes the development of anxiety in male mice. (2) The level of anxiety as well as its behavioral realization depends on the duration of aggressive experience and genetic strain. Genetically defined features of innate anxiety (trait or state) in individuals may determine the kind of association between aggressive experience, aggressive motivation and anxiety.