RESUMEN
Microglia modulate synaptic refinement in the central nervous system (CNS). We have previously shown that a mouse model with innate high anxiety-related behavior (HAB) displays higher CD68+ microglia density in the key regions of anxiety circuits compared to mice with normal anxiety-related behavior (NAB) in males, and that minocycline treatment attenuated the enhanced anxiety of HAB male. Given that a higher prevalence of anxiety is widely reported in females compared to males, little is known concerning sex differences at the cellular level. Herein, we address this by analyzing microglia heterogeneity and function in the HAB and NAB brains of both sexes. Single-cell RNA sequencing revealed ten distinct microglia clusters varied by their frequency and gene expression profile. We report striking sex differences, especially in the major microglia clusters of HABs, indicating a higher expression of genes associated with phagocytosis and synaptic engulfment in the female compared to the male. On a functional level, we show that female HAB microglia engulfed a greater amount of hippocampal vGLUT1+ excitatory synapses compared to the male. We moreover show that female HAB microglia engulfed more synaptosomes compared to the male HAB in vitro. Due to previously reported effects of minocycline on microglia, we finally administered oral minocycline to HABs of both sexes and showed a significant reduction in the engulfment of synapses by female HAB microglia. In parallel to our microglia-specific findings, we further showed an anxiolytic effect of minocycline on female HABs, which is complementary to our previous findings in the male HABs. Our study, therefore, identifies the altered function of synaptic engulfment by microglia as a potential avenue to target and resolve microglia heterogeneity in mice with innate high anxiety.
Asunto(s)
Ansiedad , Microglía , Minociclina , Caracteres Sexuales , Animales , Minociclina/farmacología , Microglía/metabolismo , Microglía/efectos de los fármacos , Femenino , Ansiedad/metabolismo , Ansiedad/tratamiento farmacológico , Masculino , Ratones , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Ratones Endogámicos C57BL , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Modelos Animales de Enfermedad , Sinapsis/efectos de los fármacos , Sinapsis/metabolismo , Fagocitosis/efectos de los fármacosRESUMEN
Aging-related neurological deficits negatively impact mental health, productivity, and social interactions leading to a pronounced socioeconomic burden. Since declining brain dopamine signaling during aging is associated with the onset of neurological impairments, we produced a selective dopamine transporter (DAT) inhibitor to restore endogenous dopamine levels and improve cognitive function. We describe the synthesis and pharmacological profile of (S,S)-CE-158, a highly specific DAT inhibitor, which increases dopamine levels in brain regions associated with cognition. We find both a potentiation of neurotransmission and coincident restoration of dendritic spines in the dorsal hippocampus, indicative of reinstatement of dopamine-induced synaptic plasticity in aging rodents. Treatment with (S,S)-CE-158 significantly improved behavioral flexibility in scopolamine-compromised animals and increased the number of spontaneously active prefrontal cortical neurons, both in young and aging rodents. In addition, (S,S)-CE-158 restored learning and memory recall in aging rats comparable to their young performance in a hippocampus-dependent hole board test. In sum, we present a well-tolerated, highly selective DAT inhibitor that normalizes the age-related decline in cognitive function at a synaptic level through increased dopamine signaling.
Asunto(s)
Proteínas de Transporte de Dopamina a través de la Membrana Plasmática , Plasticidad Neuronal , Envejecimiento , Animales , Encéfalo , Hipocampo , Plasticidad Neuronal/fisiología , RatasRESUMEN
Neuroinflammation is discussed to play a role in specific subgroups of different psychiatric disorders, including anxiety disorders. We have previously shown that a mouse model of trait anxiety (HAB) displays enhanced microglial density and phagocytic activity in key regions of anxiety circuits compared to normal-anxiety controls (NAB). Using minocycline, we provided causal evidence that reducing microglial activation within the dentate gyrus (DG) attenuated enhanced anxiety in HABs. Besides pharmacological intervention, "positive environmental stimuli", which have the advantage of exerting no side-effects, have been shown to modulate inflammation-related markers in human beings. Therefore, we now investigated whether environmental enrichment (EE) would be sufficient to modulate upregulated neuroinflammation in high-anxiety HABs. We show for the first time that EE can indeed attenuate enhanced trait anxiety, even when presented as late as adulthood. We further found that EE-induced anxiolysis was associated with the attenuation of enhanced microglial density (using Iba-1 as the marker) in the DG and medial prefrontal cortex. Additionally, EE reduced Iba1 + CD68+ microglia density within the anterior DG. Hence, the successful attenuation of trait anxiety by EE was associated in part with the normalization of neuro-inflammatory imbalances. These results suggest that pharmacological and/or positive behavioral therapies triggering microglia-targeted anti-inflammatory effects could be promising as novel alternatives or complimentary anxiolytic therapeutic approaches in specific subgroups of individuals predisposed to trait anxiety.
Asunto(s)
Ansiedad , Microglía , Animales , Ratones , Humanos , Adulto , Ansiedad/tratamiento farmacológico , Trastornos de Ansiedad , Modelos Animales de Enfermedad , Minociclina/farmacología , Minociclina/uso terapéutico , HipocampoRESUMEN
Neuropeptide S (NPS) has generated substantial interest due to its anxiolytic and fear-attenuating effects in rodents, while a corresponding receptor polymorphism associated with increased NPS receptor (NPSR1) surface expression and efficacy has been implicated in an increased risk of panic disorder in humans. To gain insight into this paradox, we examined the NPS system in rats and mice bred for high anxiety-related behavior (HAB) versus low anxiety-related behavior, and, thereafter, determined the effect of central NPS administration on anxiety- and fear-related behavior. The HAB phenotype was accompanied by lower basal NPS receptor (Npsr1) expression, which we could confirm via in vitro dual luciferase promoter assays. Assessment of shorter Npsr1 promoter constructs containing a sequence mutation that introduces a glucocorticoid receptor transcription factor binding site, confirmed via oligonucleotide pull-down assays, revealed increased HAB promoter activity-an effect that was prevented by dexamethasone. Analogous to the human NPSR1 risk isoform, functional analysis of a synonymous single nucleotide polymorphism in the coding region of HAB rodents revealed that it caused a higher cAMP response to NPS stimulation. Assessment of the behavioral consequence of these differences revealed that intracerebroventricular NPS reversed the hyperanxiety of HAB rodents as well as the impaired cued-fear extinction in HAB rats and the enhanced fear expression in HAB mice, respectively. These results suggest that alterations in the NPS system, conserved across rodents and humans, contribute to innate anxiety and fear, and that HAB rodents are particularly suited to resolve the apparent discrepancy between the preclinical and clinical findings to date.
Asunto(s)
Ansiedad/genética , Ansiedad/metabolismo , Cruzamiento , Polimorfismo de Nucleótido Simple/genética , Receptores Acoplados a Proteínas G/genética , Estimulación Acústica/métodos , Animales , Ansiedad/psicología , Cruzamiento/métodos , Miedo/fisiología , Miedo/psicología , Células HEK293 , Humanos , Masculino , Ratones , RatasRESUMEN
BACKGROUND: Despite its success in treating specific anxiety disorders, the effect of exposure therapy is limited by problems with tolerability, treatment resistance, and fear relapse after initial response. The identification of novel drug targets facilitating fear extinction in clinically relevant animal models may guide improved treatment strategies for these disorders in terms of efficacy, acceleration of fear extinction, and return of fear. METHODS: The extinction-facilitating potential of neuropeptide S, D-cycloserine, and a benzodiazepine was investigated in extinction-impaired high anxiety HAB rats and 129S1/SvImJ mice using a classical cued fear conditioning paradigm followed by extinction training and several extinction test sessions to study fear relapse. RESULTS: Administration of D-cycloserine improved fear extinction in extinction-limited, but not in extinction-deficient, rodents compared with controls. Preextinction neuropeptide S caused attenuated fear responses in extinction-deficient 129S1/SvImJ mice at extinction training onset and further reduced freezing during this session. While the positive effects of either D-cycloserine or neuropeptide S were not persistent in 129S1/SvImJ mice after 10 days, the combination of preextinction neuropeptide S with postextinction D-cycloserine rendered the extinction memory persistent and context independent up to 5 weeks after extinction training. This dual pharmacological adjunct to extinction learning also protected against fear reinstatement in 129S1/SvImJ mice. CONCLUSIONS: By using the potentially nonsedative anxiolytic neuropeptide S and the cognitive enhancer D-cycloserine to facilitate deficient fear extinction, we provide here the first evidence of a purported efficacy of a dual over a single drug approach. This approach may render exposure sessions less aversive and more efficacious for patients, leading to enhanced protection from fear relapse in the long term.
Asunto(s)
Ansiolíticos/farmacología , Ansiedad/terapia , Conducta Animal/efectos de los fármacos , Cicloserina/farmacología , Extinción Psicológica/efectos de los fármacos , Miedo/efectos de los fármacos , Terapia Implosiva/métodos , Neuropéptidos/farmacología , Animales , Ansiedad/genética , Ansiedad/psicología , Cognición/efectos de los fármacos , Condicionamiento Clásico/efectos de los fármacos , Modelos Animales de Enfermedad , Quimioterapia Combinada , Masculino , Ratones de la Cepa 129 , Ratas Endogámicas , Recurrencia , Factores de TiempoRESUMEN
Neurokinin receptors (NKRs) have been shown to be involved in many physiological processes, rendering them promising novel drug targets, but also making them the possible cause for side effects of several drugs. Aiming to answer the question whether the binding to NKRs could have a share in the side effects or even the desired effects of already licensed drugs, we generated a set of ligand-based common feature pharmacophore models based on the structural information about subtype-selective and nonselective NKR antagonists and screened an in-house database mainly composed of licensed drugs. The prospective pharmacological investigations of the virtual hits haloperidol, eprazinone, and fenbutrazate confirmed them to be NKR ligands in vitro. By the identification of licensed drugs as so far unknown NKR ligands, this study contributes to establishing an activity profile of the investigated compounds and confirms the presented pharmacophore models as useful tools for this purpose.
Asunto(s)
Haloperidol/farmacología , Fenilbutiratos/farmacología , Propiofenonas/farmacología , Receptores de Taquicininas/antagonistas & inhibidores , Bases de Datos Farmacéuticas , Descubrimiento de Drogas , Haloperidol/química , Humanos , Ligandos , Modelos Moleculares , Fenilbutiratos/química , Propiofenonas/química , Receptores de Taquicininas/metabolismoRESUMEN
The ventromedial prefrontal cortex (vmPFC; rodent infralimbic cortex (IL)), is posited to be an important locus of fear extinction-facilitating effects of the dopamine (DA) bio-precursor, L-DOPA, but this hypothesis remains to be formally tested. Here, in a model of impaired fear extinction (the 129S1/SvImJ inbred mouse strain; S1), we monitored extracellular DA dynamics via in vivo microdialysis in IL during fear extinction and following L-DOPA administration. Systemic L-DOPA caused sustained elevation of extracellular DA levels in IL and increased neuronal activation in a subpopulation of IL neurons. Systemic L-DOPA enabled extinction learning and promoted extinction retention at one but not ten days after training. Conversely, direct microinfusion of DA into IL produced long-term fear extinction (an effect that was insensitive to É-/ß-adrenoreceptor antagonism). However, intra-IL delivery of a D1-like or D2 receptor agonist did not facilitate extinction. Using ex vivo multi-electrode array IL neuronal recordings, along with ex vivo quantification of immediate early genes and DA receptor signalling markers in mPFC, we found evidence of reduced DA-evoked mPFC network responses in S1 as compared with extinction-competent C57BL/6J mice that were partially driven by D1 receptor activation. Together, our data demonstrate that locally increasing DA in IL is sufficient to produce lasting rescue of impaired extinction. The finding that systemic L-DOPA increased IL DA levels, but had only transient effects on extinction, suggests L-DOPA failed to reach a threshold level of IL DA or produced opposing behavioural effects in other brain regions. Collectively, our findings provide further insight into the neural basis of the extinction-promoting effects of DA and L-DOPA in a clinically relevant animal model, with possible implications for therapeutically targeting the DA system in anxiety and trauma-related disorders.
Asunto(s)
Dopamina , Levodopa , Animales , Ratones , Ratones Endogámicos C57BL , Levodopa/farmacología , Extinción Psicológica , Miedo , Corteza PrefrontalRESUMEN
Psychiatric disorders associated with psychological trauma, stress and anxiety are a highly prevalent and increasing cause of morbidity worldwide. Current therapeutic approaches, including medication, are effective in alleviating symptoms of anxiety disorders and posttraumatic stress disorder (PTSD), at least in some individuals, but have unwanted side-effects and do not resolve underlying pathophysiology. After a period of stagnation, there is renewed enthusiasm from public, academic and commercial parties in designing and developing drug treatments for these disorders. Here, we aim to provide a snapshot of the current state of this field that is written for neuropharmacologists, but also practicing clinicians and the interested lay-reader. After introducing currently available drug treatments, we summarize recent/ongoing clinical assessment of novel medicines for anxiety and PTSD, grouped according to primary neurochemical targets and their potential to produce acute and/or enduring therapeutic effects. The evaluation of putative treatments targeting monoamine (including psychedelics), GABA, glutamate, cannabinoid, cholinergic and neuropeptide systems, amongst others, are discussed. We emphasize the importance of designing and clinically assessing new medications based on a firm understanding of the underlying neurobiology stemming from the rapid advances being made in neuroscience. This includes harnessing neuroplasticity to bring about lasting beneficial changes in the brain rather than - as many current medications do - produce a transient attenuation of symptoms, as exemplified by combining psychotropic/cognitive enhancing drugs with psychotherapeutic approaches. We conclude by noting some of the other emerging trends in this promising new phase of drug development.
Asunto(s)
Trastornos por Estrés Postraumático , Humanos , Trastornos por Estrés Postraumático/tratamiento farmacológico , Trastornos por Estrés Postraumático/psicología , Trastornos de Ansiedad/tratamiento farmacológico , Ansiedad/tratamiento farmacológicoRESUMEN
The high structural similarity, especially in transmembrane regions, of dopamine, norepinephrine, and serotonin transporters, as well as the lack of all crystal structures of human isoforms, make the specific targeting of individual transporters rather challenging. Ligand design itself is also rather limited, as many chemists, fully aware of the synthetic and analytical challenges, tend to modify lead compounds in a way that reduces the number of chiral centers and hence limits the potential chemical space of synthetic ligands. We have previously shown that increasing molecular complexity by introducing additional chiral centers ultimately leads to more selective and potent dopamine reuptake inhibitors. Herein, we significantly extend our structure-activity relationship of dopamine transporter-selective ligands and further demonstrate how stereoisomers of defined absolute configuration may fine-tune and direct the activity towards distinct targets. From the pool of active compounds, using the examples of stereoisomers 7h and 8h, we further showcase how in vitro activity significantly differs in in vivo drug efficacy experiments, calling for proper validation of individual stereoisomers in animal studies. Furthermore, by generating a large library of compounds with defined absolute configurations, we lay the groundwork for computational chemists to further optimize and rationally design specific monoamine transporter reuptake inhibitors.
Asunto(s)
Proteínas de Transporte de Noradrenalina a través de la Membrana Plasmática , Proteínas de Transporte de Serotonina en la Membrana Plasmática , Animales , Humanos , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Transporte Biológico , Relación Estructura-Actividad , Norepinefrina , LigandosRESUMEN
An intramolecular interaction between a distal (DCRD) and a proximal regulatory domain (PCRD) within the C terminus of long Ca(v)1.3 L-type Ca(2+) channels (Ca(v)1.3(L)) is a major determinant of their voltage- and Ca(2+)-dependent gating kinetics. Removal of these regulatory domains by alternative splicing generates Ca(v)1.3(42A) channels that activate at a more negative voltage range and exhibit more pronounced Ca(2+)-dependent inactivation. Here we describe the discovery of a novel short splice variant (Ca(v)1.3(43S)) that is expressed at high levels in the brain but not in the heart. It lacks the DCRD but, in contrast to Ca(v)1.3(42A), still contains PCRD. When expressed together with α2δ1 and ß3 subunits in tsA-201 cells, Ca(v)1.3(43S) also activated at more negative voltages like Ca(v)1.3(42A) but Ca(2+)-dependent inactivation was less pronounced. Single channel recordings revealed much higher channel open probabilities for both short splice variants as compared with Ca(v)1.3(L). The presence of the proximal C terminus in Ca(v)1.3(43S) channels preserved their modulation by distal C terminus-containing Ca(v)1.3- and Ca(v)1.2-derived C-terminal peptides. Removal of the C-terminal modulation by alternative splicing also induced a faster decay of Ca(2+) influx during electrical activities mimicking trains of neuronal action potentials. Our findings extend the spectrum of functionally diverse Ca(v)1.3 L-type channels produced by tissue-specific alternative splicing. This diversity may help to fine tune Ca(2+) channel signaling and, in the case of short variants lacking a functional C-terminal modulation, prevent excessive Ca(2+) accumulation during burst firing in neurons. This may be especially important in neurons that are affected by Ca(2+)-induced neurodegenerative processes.
Asunto(s)
Empalme Alternativo , Canales de Calcio Tipo L/química , Biofisica/métodos , Encéfalo/metabolismo , Calcio/química , Canales de Calcio Tipo L/genética , Canales de Calcio Tipo L/metabolismo , Señalización del Calcio , Línea Celular , Clonación Molecular , Células HEK293 , Humanos , Iones , Neuronas/metabolismo , Técnicas de Placa-Clamp , Estructura Terciaria de Proteína , ARN/metabolismo , Transducción de SeñalRESUMEN
Patients diagnosed for anxiety disorders often display faster acquisition and slower extinction of learned fear. To gain further insights into the mechanisms underlying these phenomenona, we studied conditioned fear in mice originating form a bi-directional selective breeding approach, which is based on elevated plus-maze behavior and results in CD1-derived high (HAB), normal (NAB), and low (LAB) anxiety-related behavior mice. HAB mice displayed pronounced cued-conditioned fear compared to NAB/CD1 and LAB mice that coincided with increased phosphorylation of the protein kinase B (AKT) in the basolateral amygdala 45 min after conditioning. No similar changes were observed after non-associative immediate shock presentations. Fear extinction of recent but not older fear memories was preserved. However, HAB mice were more prone to relapse of conditioned fear with the passage of time. HAB mice also displayed higher levels of contextual fear compared to NAB and LAB mice and exaggerated avoidance following step-down avoidance training. Interestingly, HAB mice showed lower and LAB mice higher levels of acoustic startle responses compared to NAB controls. The increase in arousal observed in LAB mice coincided with the general absence of conditioned freezing. Taken together, our results suggest that the genetic predisposition to high anxiety-related behavior may increase the risk of forming traumatic memories, phobic-like fear and avoidance behavior following aversive encounters, with a clear bias towards passive coping styles. In contrast, genetic predisposition to low anxiety-related and high risk-taking behavior seems to be associated with an increase in active coping styles. Our data imply changes in AKT phosphorylation as a therapeutic target for the prevention of exaggerated fear memories.
Asunto(s)
Amígdala del Cerebelo/metabolismo , Ansiedad/metabolismo , Reacción de Prevención/fisiología , Conducta Animal/fisiología , Condicionamiento Psicológico/fisiología , Miedo/fisiología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Estimulación Acústica , Animales , Ansiedad/psicología , Señales (Psicología) , Modelos Animales de Enfermedad , Electrochoque , Extinción Psicológica/fisiología , Masculino , Ratones , FosforilaciónRESUMEN
Given the increase in benzodiazepine (BZD) and Z-drug (ZD) use disorder, this study described the use of phenobarbital (PHB) as detoxification in clinical practice. A 15-year observational retrospective study was performed on medical records of BZD-ZD use disorder patients detoxified with PHB at the Toxicology Unit and Poison Centre, Careggi University Hospital, Florence (Italy). A multivariate logistic regression was used to estimate odd ratios (ORs) and related 95% confidence intervals (CI) of "treatment failure" considering demographic and pharmacological characteristics. "Hospitalisation length", "PHB discharge dose", and "BZD-ZD free status" at discharge were also calculated. During detoxification, out of 355 patients (57% of men), with a mean age of 42.92 years, only 20 (5.6%) treatment failures were recorded: 19 were discharged against medical advice or due to misbehaviour, and only one for PHB-related non-serious skin rash. Analysis showed a higher probability to be BZD-ZD free at discharge for subjects who reported to be employed (OR 2.29; CI 95% 1.00-5.24), for those who abused oral drops of BZD-ZD (OR 2.16, CI 1.30-3.59), and for those treated with trazodone (OR 2.86, CI 1.14-7.17) during hospital stay. A hospitalisation length of > 7 days was observed for patients with opioid maintenance therapy (OR 2.07, CI 1.20-3.58) for substance use disorder, and for those treated with more than 300 mg/day of PHB equivalents at hospital admission (OR 1.68, CI 1.03-2.72). Our results suggested that PHB can be considered a valuable detoxification option for different types of BZD and ZD use disorder patients.
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Benzodiazepinas , Trastornos Relacionados con Sustancias , Adulto , Analgésicos Opioides/uso terapéutico , Benzodiazepinas/efectos adversos , Benzodiazepinas/uso terapéutico , Humanos , Masculino , Fenobarbital/uso terapéutico , Estudios Retrospectivos , Trastornos Relacionados con Sustancias/tratamiento farmacológicoRESUMEN
Previous studies have shown that atypical dopamine-transporter-inhibitors such as modafinil and its analogues modify behavioral and cognitive functions in rodents. Here, we tested potential promnestic effects of the novel, more dopamine-transporter selective modafinil analogue CE-158 in the social discrimination memory task in male mice. Systemic administration of CE-158 1 h before the social learning event prevented the impairment of social-recognition memory following retroactive interference 3 h after the learning session of a juvenile conspecific. This effect was dose-dependent, as mice treated with 10 mg/kg, but not with 1 mg/kg CE-158, were able to discriminate between the novel and familiar conspecific despite the presentation of an interference stimulus, both 3 h and 6 h post learning. However, when 10 mg/kg of the drug was administered after learning, CE-158 failed to prevent social memory from interference. Paralleling these behavioral effects, the systemic administration of 10 mg/kg CE-158 caused a rapid and sustained elevation of extracellular dopamine in the nucleus accumbens, a brain area where dopaminergic signaling plays a key role in learning and memory function, of freely moving mice, while 1 mg/kg was not sufficient for altering dopamine levels. Taken together, our findings suggest promnestic effects of the novel dopamine-transporter-inhibitor CE-158 in a social recognition memory test that may be in part mediated via increased dopamine-neurotransmission in the nucleus accumbens. Thus, selective-dopamine-transporter-inhibitors such as CE-158 may represent interesting drug candidates for the treatment of memory complaints observed in humans with cognitive impairments and dementia.
Asunto(s)
Dopamina , Núcleo Accumbens , Animales , Aprendizaje , Masculino , Ratones , Modafinilo/farmacología , Reconocimiento en PsicologíaRESUMEN
Anxiety is integrated in the amygdaloid nuclei and involves the interplay of the amygdala and various other areas of the brain. Neuropeptides play a critical role in regulating this process. Neuropeptide Y (NPY), a 36 aa peptide, is highly expressed in the amygdala. It exerts potent anxiolytic effects through cognate postsynaptic Y1 receptors, but augments anxiety through presynaptic Y2 receptors. To identify the precise anatomical site(s) of Y2-mediated anxiogenic action, we investigated the effect of site-specific deletion of the Y2 gene in amygdaloid nuclei on anxiety and depression-related behaviors in mice. Ablating the Y2 gene in the basolateral and central amygdala resulted in an anxiolytic phenotype, whereas deletion in the medial amygdala or in the bed nucleus of the stria terminalis had no obvious effect on emotion-related behavior. Deleting the Y2 receptor gene in the central amygdala, but not in any other amygdaloid nucleus, resulted in an added antidepressant-like effect. It was associated with a reduction of presumably presynaptic Y2 receptors in the stria terminalis/bed nucleus of the stria terminalis, the nucleus accumbens, and the locus ceruleus. Our results are evidence of the highly site-specific nature of the Y2-mediated function of NPY in the modulation of anxiety- and depression-related behavior. The activity of NPY is likely mediated by the presynaptic inhibition of GABA and/or NPY release from interneurons and/or efferent projection neurons of the basolateral and central amygdala.
Asunto(s)
Amígdala del Cerebelo/fisiología , Ansiedad/genética , Depresión/genética , Neuropéptido Y/fisiología , Receptores de Neuropéptido Y/genética , Receptores de Neuropéptido Y/fisiología , Amígdala del Cerebelo/metabolismo , Animales , Ansiedad/metabolismo , Ansiedad/fisiopatología , Depresión/metabolismo , Depresión/fisiopatología , Modelos Animales de Enfermedad , Locus Coeruleus/metabolismo , Masculino , Ratones , Ratones Noqueados , Neuropéptido Y/metabolismo , Núcleos Septales/metabolismo , Núcleos Septales/fisiologíaRESUMEN
Increasing evidence suggests that specific physiological measures may serve as biomarkers for successful treatment to alleviate symptoms of pathological anxiety. Studies of autonomic function investigating parameters such as heart rate (HR), HR variability and blood pressure (BP) indicated that HR variability is consistently reduced in anxious patients, whereas HR and BP data show inconsistent results. Therefore, HR and HR variability were measured under various emotionally challenging conditions in a mouse model of high innate anxiety (high anxiety behaviour; HAB) vs. control normal anxiety-like behaviour (NAB) mice. Baseline HR, HR variability and activity did not differ between mouse lines. However, after cued Pavlovian fear conditioning, both elevated tachycardia and increased fear responses were observed in HAB mice compared to NAB mice upon re-exposure to the conditioning stimulus serving as the emotional stressor. When retention of conditioned fear was tested in the home cage, HAB mice again displayed higher fear responses than NAB mice, while the HR responses were similar. Conversely, in both experimental settings HAB mice consistently exhibited reduced HR variability. Repeated administration of the anxiolytic NK1 receptor antagonist L-822429 lowered the conditioned fear response and shifted HR dynamics in HAB mice to a more regular pattern, similar to that in NAB mice. Additional receiver-operating characteristic (ROC) analysis demonstrated the high specificity and sensitivity of HR variability to distinguish between normal and high anxiety trait. These findings indicate that assessment of autonomic response in addition to freezing might be a useful indicator of the efficacy of novel anxiolytic treatments.
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Ansiolíticos/farmacología , Ansiedad/tratamiento farmacológico , Sistema Nervioso Autónomo/efectos de los fármacos , Conducta Animal/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Corazón/inervación , Piperidinas/farmacología , Taquicardia/tratamiento farmacológico , Animales , Ansiedad/etiología , Ansiedad/fisiopatología , Ansiedad/psicología , Sistema Nervioso Autónomo/fisiopatología , Ritmo Circadiano , Condicionamiento Psicológico/efectos de los fármacos , Señales (Psicología) , Modelos Animales de Enfermedad , Electrocardiografía Ambulatoria , Electrochoque , Miedo/efectos de los fármacos , Femenino , Ratones , Actividad Motora/efectos de los fármacos , Antagonistas del Receptor de Neuroquinina-1 , Ruido , Curva ROC , Taquicardia/etiología , Taquicardia/fisiopatología , Taquicardia/psicología , Telemetría , Factores de Tiempo , Grabación en VideoRESUMEN
There is evidence to suggest that low levels of magnesium (Mg) are associated with affective disorders, however, causality and central neurobiological mechanisms of this link are largely unproven. We have recently shown that mice fed a low Mg-containing diet (10% of daily requirement) display enhanced depression-like behavior sensitive to chronic antidepressant treatment. The aim of the present study was to utilize this model to gain insight into underlying mechanisms by quantifying amygdala/hypothalamus protein expression using gel-based proteomics and correlating changes in protein expression with changes in depression-like behavior. Mice fed Mg-restricted diet displayed reduced brain Mg tissue levels and altered expression of four proteins, N(G),N(G)-dimethylarginine dimethylaminohydrolase 1 (DDAH1), manganese-superoxide dismutase (MnSOD), glutamate dehydrogenase 1 (GDH1) and voltage-dependent anion channel 1. The observed alterations in protein expression may indicate increased nitric oxide production, increased anti-oxidant response to increased oxidative stress and potential alteration in energy metabolism. Aberrant expressions of DDAH1, MnSOD and GDH1 were normalized by chronic paroxetine treatment which also normalized the enhanced depression-like behavior, strengthening the link between the changes in these proteins and depression-like behavior. Collectively, these findings provide first evidence of low magnesium-induced alteration in brain protein levels and biochemical pathways, contributing to central dysregulation in affective disorders.
Asunto(s)
Amidohidrolasas/metabolismo , Depresión/genética , Glutamato Deshidrogenasa/metabolismo , Superóxido Dismutasa/metabolismo , Canal Aniónico 1 Dependiente del Voltaje/metabolismo , Amidohidrolasas/genética , Amígdala del Cerebelo/enzimología , Amígdala del Cerebelo/fisiopatología , Animales , Antidepresivos/administración & dosificación , Antidepresivos/uso terapéutico , Depresión/tratamiento farmacológico , Depresión/etiología , Depresión/metabolismo , Depresión/fisiopatología , Dieta/efectos adversos , Electroforesis en Gel Bidimensional , Perfilación de la Expresión Génica , Glutamato Deshidrogenasa/genética , Hipotálamo/enzimología , Hipotálamo/fisiopatología , Deficiencia de Magnesio/complicaciones , Masculino , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico/biosíntesis , Estrés Oxidativo , Paroxetina/administración & dosificación , Paroxetina/uso terapéutico , Proteómica , Superóxido Dismutasa/genética , Espectrometría de Masas en Tándem , Canal Aniónico 1 Dependiente del Voltaje/genéticaRESUMEN
High trait anxiety is a substantial risk factor for developing anxiety disorders and depression. While neuroinflammation has been identified to contribute to stress-induced anxiety, little is known about potential dysregulation in the neuroinflammatory system of genetically determined pathological anxiety or high trait anxiety individuals. We report microglial alterations in various brain regions in a mouse model of high trait anxiety (HAB). In particular, the dentate gyrus (DG) of the hippocampus of HABs exhibited enhanced density and average cell area of Iba1+, and density of phagocytic (CD68+/Iba1+) microglia compared to normal anxiety (NAB) controls. Minocycline was used to assess the capacity of a putative microglia 'inhibitor' in modulating hyperanxiety behavior of HABs. Chronic oral minocycline indeed reduced HAB hyperanxiety, which was associated with significant decreases in Iba1+ and CD68+Iba1+ cell densities in the DG. Addressing causality, it was demonstrated that longer (10 days), but not shorter (5 days), periods of minocycline microinfusions locally into the DG of HAB reduced Iba-1+ cell density and attenuated hyperanxiety-related behavior, indicating that neuroinflammation in the DG is at least partially involved in the maintenance of pathological anxiety. The present data reveal evidence of disturbances in the microglial system of individuals with high trait anxiety. Minocycline attenuated HAB hyperanxiety, likely by modulation of microglial activity within the DG. Thus, the present data suggest that drugs with microglia-targeted anti-inflammatory properties could be promising as novel alternative or complimentary anxiolytic therapeutic approaches in specific subgroups of individuals genetically predisposed to hyperanxiety.
Asunto(s)
Ansiolíticos , Minociclina , Animales , Ansiedad/tratamiento farmacológico , Trastornos de Ansiedad/tratamiento farmacológico , Ratones , Microglía , Minociclina/farmacologíaRESUMEN
Atypical dopamine reuptake inhibitors, such as modafinil, are used for the treatment of sleeping disorders and investigated as potential therapeutics against cocaine addiction and for cognitive enhancement. Our continuous effort to find modafinil analogues with higher inhibitory activity on and selectivity toward the dopamine transporter (DAT) has previously led to the promising thiazole-containing derivatives CE-103, CE-111, CE-123, and CE-125. Here, we describe the synthesis and activity of a series of compounds based on these scaffolds, which resulted in several new selective DAT inhibitors and gave valuable insights into the structure-activity relationships. Introduction of the second chiral center and subsequent chiral separations provided all four stereoisomers, whereby the S-configuration on both generally exerted the highest activity and selectivity on DAT. The representative compound of this series was further characterized by in silico, in vitro, and in vivo studies that have demonstrated both safety and efficacy profile of this compound class.
Asunto(s)
Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/antagonistas & inhibidores , Inhibidores de Captación de Dopamina/farmacología , Modafinilo/análogos & derivados , Modafinilo/farmacología , Inhibidores de Captación de Serotonina y Norepinefrina/farmacología , Tiazoles/farmacología , Animales , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/metabolismo , Inhibidores de Captación de Dopamina/síntesis química , Inhibidores de Captación de Dopamina/metabolismo , Inhibidores de Captación de Dopamina/farmacocinética , Células HEK293 , Humanos , Masculino , Modafinilo/metabolismo , Modafinilo/farmacocinética , Simulación del Acoplamiento Molecular , Estructura Molecular , Proteínas de Transporte de Noradrenalina a través de la Membrana Plasmática/antagonistas & inhibidores , Unión Proteica , Ratas Sprague-Dawley , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Inhibidores de Captación de Serotonina y Norepinefrina/síntesis química , Inhibidores de Captación de Serotonina y Norepinefrina/metabolismo , Inhibidores de Captación de Serotonina y Norepinefrina/farmacocinética , Estereoisomerismo , Relación Estructura-Actividad , Tiazoles/síntesis química , Tiazoles/metabolismo , Tiazoles/farmacocinéticaRESUMEN
The L-type calcium channel (LTCC) isoforms Ca(v)1.2 and Ca(v)1.3 display similar 1,4-dihydropyridine (DHP) binding properties and are both expressed in mammalian brain. Recent work implicates Ca(v)1.3 channels as interesting drug targets, but no isoform-selective modulators exist. It is also unknown to what extent Ca(v)1.1 and Ca(v)1.4 contribute to L-type-specific DHP binding activity in brain. To address this question and to determine whether DHPs can discriminate between Ca(v)1.2 and Ca(v)1.3 binding pockets, we combined radioreceptor assays and quantitative polymerase chain reaction (qPCR). We bred double mutants (Ca(v)-DM) from mice expressing mutant Ca(v)1.2 channels [Ca(v)1.2DHP(-/-)] lacking high affinity for DHPs and from Ca(v)1.3 knockouts [Ca(v)1.3(-/-)]. (+)-[(3)H]isradipine binding to Ca(v)1.2DHP(-/-) and Ca(v)-DM brains was reduced to 15.1 and 4.4% of wild type, respectively, indicating that Ca(v)1.3 accounts for 10.7% of brain LTCCs. qPCR revealed that Ca(v)1.1 and Ca(v)1.4 alpha(1) subunits comprised 0.08% of the LTCC transcripts in mouse whole brain, suggesting that they cannot account for the residual binding. Instead, this could be explained by low-affinity binding (127-fold K(d) increase) to the mutated Ca(v)1.2 channels. Inhibition of (+)-[(3)H]isradipine binding to Ca(v)1.2DHP(-/-) (predominantly Ca(v)1.3) and wild-type (predominantly Ca(v)1.2) brain membranes by unlabeled DHPs revealed a 3- to 4-fold selectivity of nitrendipine and nifedipine for the Ca(v)1.2 binding pocket, a finding further confirmed with heterologously expressed channels. This suggests that small differences in their binding pockets may allow development of isoform-selective modulators for LTCCs and that, because of their very low expression, Ca(v)1.1 and Ca(v)1.4 are unlikely to serve as drug targets to treat CNS diseases.
Asunto(s)
Canales de Calcio Tipo L/metabolismo , Dihidropiridinas/metabolismo , Isoformas de Proteínas/metabolismo , Secuencias de Aminoácidos/fisiología , Animales , Encéfalo/metabolismo , Canales de Calcio Tipo L/genética , Femenino , Expresión Génica , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Isoformas de Proteínas/genéticaRESUMEN
In different behavioral paradigms including the elevated plus maze (EPM), it was observed previously that deletion of the neuropeptide Y Y2 receptor subtype results in potent suppression of anxiety-related and stress-related behaviors. To identify neurobiological correlates underlying this behavioral reactivtiy, expression of c-Fos, an established early marker of neuronal activation, was examined in Y2 receptor knockout (Y2(-/-)) vs. wildtype (WT) mice. Mice were placed on the open arm (OA) or closed arm (CA) of the EPM for 10 min and the effect on regional c-Fos expression in the brain was investigated. The number of c-Fos positive neurons was significantly increased in both WT and Y2(-/-) lines after OA and CA exposure in 51 of 54 regions quantified. These regions included various cortical, limbic, thalamic, hypothalamic, and hindbrain regions. Genotype influenced c-Fos responses to arm exposures in 6 of the 51 activated regions: the cingulate cortex, barrel field of the primary somatosensory cortex, nucleus accumbens, dorsal lateral septum, amygdala and lateral periaqueductal gray. These differences in neuronal activity responses to the novel environments were more pronounced after OA than after CA exposure. Mice lacking Y2 receptors exhibited reduced neuronal activation when compared to WT animals in response to the emotional stressors. Reduced neuronal excitability in the identified brain areas relevant to the processing of motivated, explorative as well as anxiety-related behaviors is suggested to contribute to the reduced anxiety-related behavior observed in Y2(-/-) mice.