Depression and neurological disorders

Recent advances in nanotechnology for Parkinson's disease: diagnosis, treatment, and future perspectives

Parkinson's disease is a progressive neurodegenerative disease that destroys substantia nigra dopaminergic neurons, causing tremors, bradykinesia, rigidity, and postural instability. Current treatment approaches primarily focus on symptom management, employing pharmacological, non-pharmacological, and surgical methods. However, these treatments often result in fluctuating symptoms, side effects, and disease progression. Here, the authors have reviewed the emerging field of nanomedicine as a promising path for Parkinson's disease treatment, emphasizing its potential to overcome the limitations of traditional therapies. Nanomedicine utilizes nanoparticles for targeted drug delivery, leveraging their small size and high surface area to volume ratio to cross the blood-brain barrier and deliver therapeutic agents directly to affected brain regions. Various nanoparticles, including lipid-based, polymeric, metallic, and carbon-based, have shown potential in Parkinson's disease treatment. Additionally, nanocarrier systems like liposomes, nanogels, dendrimers, and solid lipid nanoparticles offer controlled and sustained release of therapeutic agents, enhancing their bioavailability and reducing side effects. This review provides insights into the pathophysiology of Parkinson's disease, highlighting the mechanisms of neurodegeneration, the role of alpha-synuclein, and the disruption of dopaminergic pathways. It further discusses the application of gene therapy in conjunction with nanomedicine for targeted therapeutic interventions.

Psychological Factors Influencing Adherence to NIV in Neuromuscular Patients Dependent on Non Invasive Mechanical Ventilation: Preliminary Results

BACKGROUND

Non-invasive ventilation (NIV) is associated with improvement of both morbility and mortality in patients affected by neuromuscular diseases with chronic respiratory failure. Several studies have also shown that long-term NIV positively impacts the patient's quality of life and perception of disease status. Its effectiveness is likely related to the adherence to NIV. Several factors, patient- and not patient-related, may compromise adherence to NIV, such as physical, behavioral, familiar, and social issues. Few data are currently available on the role of psychological factors in influencing NIV adherence.

MATERIALS AND METHODS

In this pilot study, we evaluated the adherence to NIV in a group of 15 adult patients with neuromuscular diseases (Duchenne muscular dystrophy, myotonic dystrophy, and amyotrophic lateral sclerosis) in relation to their grade of depression assessed by the Beck Depression Inventory (BDI) questionnaire. Other data were collected, such as clinical features (age and sex), use of anxiolytic drugs, the presence of a family or professional caregiver, the quality of patient-physician relationship, the beginning of psychological support after BDI screening, and the family acceptance of NIV. NIV adherence was definied as the use of NIV for at least 4 h per night on 70% of nights in a month.

RESULTS

The overall rate of NIV adherence was 60%. Based on the BDI questionnaire, patients who were non-adherent to NIV had a higher rate of depression, mainly observed in the oldest patients. The acceptance of NIV by the family and positive physician-patient interaction seem to favor NIV adherence.

CONCLUSION

Depression can interfere with NIV adherence in patients with neuromuscolar diseases.

Depression in Major Neurodegenerative Diseases and Strokes: A Critical Review of Similarities and Differences among Neurological Disorders

Depression and anxiety are highly prevalent in most neurological disorders and can have a major impact on the patient's disability and quality of life. However, mostly due to the heterogeneity of symptoms and the complexity of the underlying comorbidities, depression can be difficult to diagnose, resulting in limited recognition and in undertreatment. The early detection and treatment of depression simultaneously with the neurological disorder is key to avoiding deterioration and further disability. Although the neurologist should be able to identify and treat depression initially, a neuropsychiatry team should be available for severe cases and those who are unresponsive to treatment. Neurologists should be also aware that in neurodegenerative diseases, such as Alzheimer's or Parkinson's, different depression symptoms could develop at different stages of the disease. The treatment options for depression in neurological diseases include drugs, cognitive-behavioral therapy, and somatic interventions, among others, but often, the evidence-based efficacy is limited and the results are highly variable. Here, we review recent research on the diagnosis and treatment of depression in the context of Alzheimer's disease, Parkinson's disease, and strokes, with the aim of identifying common approaches and solutions for its initial management by the neurologist.

A large-scale polygenic risk score analysis identified candidate proteins associated with anxiety, depression and neuroticism

Psychiatric disorders and neuroticism are closely associated with central nervous system, whose proper functioning depends on efficient protein renewal. This study aims to systematically analyze the association between anxiety / depression / neuroticism and each of the 439 proteins. 47,536 pQTLs of 439 proteins in brain, plasma and cerebrospinal fluid (CSF) were collected from recent genome-wide association study. Polygenic risk scores (PRS) of the 439 proteins were then calculated using the UK Biobank cohort, including 120,729 subjects of neuroticism, 255,354 subjects of anxiety and 316,513 subjects of depression. Pearson correlation analyses were performed to evaluate the correlation between each protein and each of the mental traits by using calculated PRSs as the instrumental variables of protein. In general population, six correlations were identified in plasma and CSF such as plasma protease C1 inhibitor (C1-INH) with neuroticism score (r = - 0.011, P = 2.56 × 10^- 9) in plasma, C1-INH with neuroticism score (r = -0.010, P = 3.09 × 10^- 8) in CSF, and ERBB1 with self-reported depression (r = - 0.012, P = 4.65 × 10^- 5) in CSF. C1-INH and ERBB1 may induce neuroticism and depression by affecting brain function and synaptic development. Gender subgroup analyses found that BST1 was correlated with neuroticism score in male CSF (r = - 0.011, P = 1.80 × 10^- 5), while CNTN2 was correlated with depression score in female brain (r = - 0.013, P = 6.43 × 10^- 4). BST1 and CNTN2 may be involved in nervous system metabolism and brain health. Six common candidate proteins were associated with all three traits (P < 0.05) and were confirmed in relevant proteomic studies, such as C1-INH in plasma, CNTN2 and MSP in the brain. Our results provide novel clues for revealing the roles of proteins in the development of anxiety, depression and neuroticism.

Emerging promise of sulforaphane-mediated Nrf2 signaling cascade against neurological disorders

Neurological disorders represent a great challenge and are the leading cause of death and disability globally. Although numerous complicated mechanisms are involved in the progressions of chronic and acute neurodegenerative disorders, most of the diseases share mutual pathogenic features such as oxidative stress, mitochondrial dysfunction, neuroinflammation, protein misfolding, excitotoxicity, and neuronal damage, all of these are the common targets of nuclear factor erythroid 2 related factor 2 (Nrf2) signaling cascade. No cure has yet been discovered to tackle these disorders, so, intervention approaches targeting phytochemicals have been recommended as an alternative form of treatment. Sulforaphane is a sulfur-rich dietary phytochemical which has several activities such as antioxidant, anti-inflammatory, and anti-tumor via multiple targets and various mechanisms. Given its numerous actions, sulforaphane has drawn considerable attention for neurological disorders in recent years. Nrf2 is one of the most crucial targets of sulforaphane which has potential in regulating the series of cytoprotective enzyme expressions that have neuroprotective, antioxidative, and detoxification actions. Neurological disorders are auspicious candidates for Nrf2-targeted treatment strategy. Sulforaphane protects various neurological disorders by regulating the Nrf2 pathway. In this article, we recapitulate current studies of sulforaphane-mediated Nrf2 activation in the treatment of various neurological disorders.

Balance Problems, Paralysis, and Angina as Clinical Markers for Severity in Major Depression

Major depressive disorder (MDD) is a heterogeneous disorder. Our hypothesis is that neurological symptoms correlate with the severity of MDD symptoms. One hundred eighty-four outpatients with MDD completed a self-report questionnaire on past and present medical history. Patients were divided into three roughly equal depression severity levels based on scores from the APA Severity Measure for Depression-Adult (n = 66, 58, 60, for low, medium, high severity, respectively). We saw a significant and gradual increase in the frequency of "muscular paralysis" (1.5-5.2-16.7%) and "balance problems" (21.2-36.2-46.6%) from low to medium to high severity groups. We repeated the analysis using only the two most extreme severity categories: low severity (66 samples) vs. high severity (60 samples). High severity patients were also found to experience more "angina" symptoms than low severity patients (27.3 vs. 50%). The three significant clinical variables identified were introduced into a binary logistic regression model as the independent variables with high or low severity as the dependent variable. Both "muscular paralysis" and "balance problems" were significantly associated with increased severity of depression (odds ratio of 13.5 and 2.9, respectively), while "angina" was associated with an increase in severity with an odds ratio of 2.0, albeit not significantly. We show that neurological exam or clinical history could be useful biomarkers for depression severity. Our findings, if replicated, could lead to a simple clinical scale administered regularly for monitoring patients with MDD.

Myalgic encephalomyelitis/chronic fatigue syndrome: From pathophysiological insights to novel therapeutic opportunities

Myalgic encephalomyelitis (ME) or chronic fatigue syndrome (CFS) is a common and disabling condition with a paucity of effective and evidence-based therapies, reflecting a major unmet need. Cognitive behavioural therapy and graded exercise are of modest benefit for only some ME/CFS patients, and many sufferers report aggravation of symptoms of fatigue with exercise. The presence of a multiplicity of pathophysiological abnormalities in at least the subgroup of people with ME/CFS diagnosed with the current international consensus "Fukuda" criteria, points to numerous potential therapeutic targets. Such abnormalities include extensive data showing that at least a subgroup has a pro-inflammatory state, increased oxidative and nitrosative stress, disruption of gut mucosal barriers and mitochondrial dysfunction together with dysregulated bioenergetics. In this paper, these pathways are summarised, and data regarding promising therapeutic options that target these pathways are highlighted; they include coenzyme Q₁₀, melatonin, curcumin, molecular hydrogen and N-acetylcysteine. These data are promising yet preliminary, suggesting hopeful avenues to address this major unmet burden of illness.

Patterns of Co-occurring Comorbidities in People Living With HIV

Background

The aims of this study were to identify common patterns of comorbidities observed in people living with HIV (PLWH), using a data-driven approach, and evaluate associations between patterns identified.

Methods

A wide range of comorbidities were assessed in PLWH participating in 2 independent cohorts (POPPY: UK/Ireland; AGEhIV: Netherlands). The presence/absence of each comorbidity was determined using a mix of self-reported medical history, concomitant medications, health care resource use, and laboratory parameters. Principal component analysis (PCA) based on Somers' D statistic was applied to identify patterns of comorbidities.

Results

PCA identified 6 patterns among the 1073 POPPY PLWH (85.2% male; median age [interquartile range {IQR}], 52 [47-59] years): cardiovascular diseases (CVDs), sexually transmitted diseases (STDs), mental health problems, cancers, metabolic disorders, chest/other infections. The CVDs pattern was positively associated with cancer (r = .32), metabolic disorder (r = .38), mental health (r = .16), and chest/other infection (r = .17) patterns (all P < .001). The mental health pattern was correlated with all the other patterns (in particular cancers: r = .20; chest/other infections: r = .27; both P < .001). In the 598 AGEhIV PLWH (87.6% male; median age [IQR], 53 [48-59] years), 6 patterns were identified: CVDs, chest/liver, HIV/AIDS events, mental health/neurological problems, STDs, and general health. The general health pattern was correlated with all the other patterns (in particular CVDs: r = .14; chest/liver: r = .15; HIV/AIDS events: r = .31; all P < .001), except STDs (r = -.02; P = .64).

Conclusions

Comorbidities in PLWH tend to occur in nonrandom patterns, reflecting known pathological mechanisms and shared risk factors, but also suggesting potential previously unknown mechanisms. Their identification may assist in adequately addressing the pathophysiology of increasingly prevalent multimorbidity in PLWH.

Subjective measures of health and all-cause mortality - the Rotterdam Study

BACKGROUND

Subjectively assessed health is related to mortality. Various subjective indicators of health have been studied, but it is unclear whether perceived physical functioning or mental health best accounts for the relation with mortality.

METHOD

We studied the relation of subjective measures of health with all-cause mortality in 5538 participants of age 55 to 96 years at baseline from the Rotterdam Study. Various instruments of subjectively assessed health were used, that included basic activities of daily living (BADL), instrumental activities of daily living (IADL), quality of life (QoL), positive affect, somatic symptoms and negative affect. All participants completed questionnaires for each subjective measure of health and were followed for mortality for a mean of 12.2 (s.e. = 0.09) years. Cox regression analysis was conducted in the total sample.

RESULTS

In this cohort, 2021 persons died during 48 534 person-years of follow-up. All measures of subjective health were related to mortality after adjusting for age, gender, education, cognition, prevalent chronic diseases and cardiovascular risk [BADL hazard ratio (HR, calculated per Z-score) = 1.35, 95% confidence interval (CI) 1.29-1.41; IADL HR = 1.27, 95% CI 1.22-1.32; QoL HR = 0.85, 95% CI 0.81-0.89; positive affect HR = 0.92, 95% CI 0.88-0.96; somatic symptoms HR = 1.11, 95% CI 1.06-1.16; and negative affect HR = 1.05, 95% CI 1.01-1.10]. In the mutually adjusted model, only BADL (HR = 1.24, 95% CI 1.16-1.32) and IADL (HR = 1.10, 95% CI 1.04-1.17) remained independently associated with mortality.

CONCLUSIONS

Measures of subjectively assessed health are important indicators of mortality. Our study shows that of the different measures of subjective health, perceived physical health predicts mortality over and above mental health. Conversely, the association between mental health and mortality may partly be explained by poor perceived physical health.

Depressive Symptoms Negatively Impact Montreal Cognitive Assessment Performance: A Memory Clinic Experience

Objective:The Montreal Cognitive Assessment (MoCA) is a general cognitive screening tool that has shown sensitivity in detecting mild levels of cognitive impairment in various clinical populations. Although mood dysfunction is common in referrals to memory clinics, the influence of mood on the MoCA has to date been largely unexplored.Method:In this study, we examined the impact of mood dysfunction on the MoCA using a memory clinic sample of individuals with depressive symptoms who did not meet criteria for a neurodegenerative disease.Results:Half of the group with depressive symptoms scored below the MoCA-suggested cutoff for cognitive impairment. As a group, they scored below healthy controls, but above individuals with Alzheimer’s disease and frontotemporal dementia. A MoCA subtask analysis revealed a pattern of executive/attentional dysfunction in those with depressive symptoms.Conclusions:This observed negative impact of depressive symptomatology on the MoCA has interpretative implications for its utility as a cognitive screening tool in a memory clinic setting.

Moderation of antidepressant and placebo outcomes by baseline severity in late-life depression: A systematic review and meta-analysis

BACKGROUND

Baseline severity is a crucial moderator of trial outcomes in adult depression, with the advantage of antidepressants over placebo increasing as severity increases. However, this relationship has not been examined in late-life depression.

METHODS

PubMed, Embase, Web of Science, PsycINFO, and Cochrane were searched for studies published through September 2014. Randomized, acute phase, and double-blind studies comparing an antidepressant group with a placebo group in depressed elderly patients were included.

RESULTS

Nineteen studies met all inclusion criteria. Within-group effect sizes revealed significant improvement in antidepressant groups (g=1.35, p<.000), as well as in placebo groups (g=.96, p<.000). Change in depressive symptoms assessed by Hamilton Depression Rating Scale (HDRS) was moderated by baseline severity in antidepressant groups (Z=2.67, p=.008) and placebo groups (Z=4.46, p<.000). However, this would be expected as a result of regression toward the mean, and mean differences between groups did not increase (r=.19, p=.469) as a function of baseline severity.

LIMITATIONS

Limited to published data and information was only analyzed at the level of treatment groups.

CONCLUSION

Baseline severity was not associated with an antidepressant-placebo difference and placebo responses are large in the treatment of depressed elderly people. We propose a stepwise approach, i.e., to initially offer elderly depressed patients psychosocial interventions and only consider antidepressants if patients do not respond.

The amount of TMJ displacement correlates with brain activity

The aim of this functional magnetic resonance imaging (fMRI) study was to investigate the correlation between the severity of malocclusion and brain activation. The fMRI was used to measure blood-oxygenation- level-dependent (BOLD) signals of twelve healthy human subjects while they clenched in two different ways to simulate two types of malocclusion. In each malocclusion model, a custom-made splint forced the mandible to each of two retrusive positions (0.5 mm, 0.7 mm). A no-modification splint provided the control. We compared the BOLD signals measured at each clenching position with those measured during the corresponding resting conditions. The BOLD signals were significantly stronger in the amygdala and the prefrontal area (PFA) when subjects clenched in the two retrusive positions compared during clenching in the control position. In addition, the BOLD signal in the PFA increased as the simulated malocclusion became more severe. These results indicate that we may be able to objectively assess the severity of malocclusion via focus on the brain activity.

Implicit awareness in anosognosia for hemiplegia: unconscious interference without conscious re-representation

Some patients with anosognosia for hemiplegia, i.e. apparent unawareness of hemiplegia, have been clinically observed to show 'tacit' or 'implicit' awareness of their deficits. Here we have experimentally examined whether implicit and explicit responses to the same deficit-related material can dissociate. Fourteen stroke patients with right hemisphere lesions and contralesional paralysis were tested for implicit and explicit responses to brief sentences with deficit-related themes. These responses were elicited using: (i) a verbal inhibition test in which patients had to inhibit completing each sentence with an automatic response (implicit task) and (ii) a rating procedure in which patients rated the self-relevance of the same sentences (explicit task). A group of anosognosic hemiplegic patients was significantly slower than a control group of aware hemiplegic patients in performing the inhibition task with deficit-related sentences than with other emotionally negative themes (relative to neutral themes). This occurred despite their explicit denial of the self-relevance of the former sentences. Individual patient analysis showed that six of the seven anosognosic patients significantly differed from the control group in this dissociation. Using lesion mapping procedures, we found that the lesions of the anosognosic patients differed from those of the 'aware' controls mainly by involving the anterior parts of the insula, inferior motor areas, basal ganglia structures, limbic structures and deep white matter. In contrast, the anosognosic patient without implicit awareness had more cortical lesions, mostly in frontal areas, including lateral premotor regions, and also in the parietal and occipital lobes. These results provide strong experimental support for a specific dissociation between implicit and explicit awareness of deficits. More generally, the combination of our behavioural and neural findings suggests that an explicit, affectively personalized sensorimotor awareness requires the re-representation of sensorimotor information in the insular cortex, with possible involvement of limbic areas and basal ganglia circuits. The delusional features of anosognosia for hemiplegia can be explained as a failure of this re-representation.

Neuromodulation approaches for the treatment of major depression: challenges and recommendations from a working group meeting

The use of neuromodulation as a treatment for major depressive disorder (MDD) has recently attracted renewed interest due to development of other non-pharmacological therapies besides electroconvulsive therapy (ECT) such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), and vagus nerve stimulation (VNS). METHOD: We convened a working group of researchers to discuss the updates and key challenges of neuromodulation use for the treatment of MDD. RESULTS: The state-of-art of neuromodulation techniques was reviewed and discussed in four sections: [1] epidemiology and pathophysiology of MDD; [2] a comprehensive overview of the neuromodulation techniques; [3] using neuromodulation techniques in MDD associated with non-psychiatric conditions; [4] the main challenges of neuromodulation research and alternatives to overcome them. DISCUSSION: ECT is the first-line treatment for severe depression. TMS and tDCS are strategies with a relative benign profile of side effects; however, while TMS effects are comparable to antidepressant drugs for treating MDD; further research is needed to establish the role of tDCS. DBS and VNS are invasive strategies with a possible role in treatment-resistant depression. In summary, MDD is a chronic and incapacitating condition with a high prevalence; therefore clinicians should consider all the treatment options including invasive and non-invasive neuromodulation approaches.

Depression in Myotonic Dystrophy type 1: clinical and neuronal correlates

BACKGROUND

This study was designed to investigate the prevalence and correlates of depression in Myotonic dystrophy type 1 (DM1).

METHODS

Thirty-one patients with DM1 and 47 subjects in a clinical contrast group, consisting of other neuromuscular disorders, including Spinal muscular atrophy, Limb girdle muscle atrophy and Facioscapulohumeral dystrophy, completed Beck Depression Inventory (BDI). We aimed to establish whether different factors associated with DM1 correlated with ratings in the BDI.

RESULTS

Signs of a clinical depression were prevalent in 32% of the patients with DM1, which was comparable with ratings in the clinical contrast group. The depressive condition was mild to moderate in both groups. In DM1, a longer duration of clinical symptoms was associated with lower scores on the BDI and higher educational levels were correlated with higher scores on depression. We also found a negative association with brain white matter lesions.

CONCLUSIONS

Findings indicate significantly more DM1 patients than normative collectives showing signs of a clinical depression. The depressive condition is however mild to moderate and data indicate that the need for intervention is at hand preferentially early during the disease process.

A cognitive neuroscience hypothesis of mood and depression

Although mood has a direct impact on mental and physical health, our understanding of the mechanisms underlying mood regulation is limited. Here, I propose that there is a direct reciprocal relation between the cortical activation of associations and mood regulation, whereby positive mood promotes associative processing, and associative processing promotes positive mood. This relation might stem from an evolutionary pressure for learning and predicting. Along these lines, one can think of mood as a reward mechanism that guides individuals to use their brains in the most productive manner. The proposed framework has many implications, most notably for diagnosing and treating mood disorders such as depression; for elucidating the role of inhibition in the regulation of mood; for contextualizing adult hippocampal neurogenesis; and for a general, non-invasive improvement of well-being.

Limbic and frontal cortical degeneration is associated with psychiatric symptoms in PINK1 mutation carriers

BACKGROUND

Mutations in the PINK1 gene can cause Parkinson's disease and are frequently associated with psychiatric symptoms that might even precede motor signs.

METHODS

To determine whether specific gray matter degeneration of limbic and frontal structures might be liable to different psychiatric symptoms in PINK1 mutation carriers, observer-independent voxel-based morphometry was applied to high-resolution magnetic resonance images of 14 PINK1 mutation carriers from a large German family and 14 age- and gender-matched healthy control subjects.

RESULTS

Psychiatric diagnoses in PINK1 mutation carriers comprised major depression without psychotic symptoms and schizophrenia-spectrum, panic, adjustment, and obsessive-compulsive personality disorders. As hypothesized, the categorical comparison between all PINK1 mutation carriers and control subjects demonstrated atrophy of limbic structures, especially the hippocampus and parahippocampus. More specifically, multiple regression analysis considering all psychiatric subscores simultaneously displayed different frontal (prefrontal, dorsolateral, and premotor cortex) and limbic (parahippocampus and cingulate) degeneration patterns. The duration of the psychiatric disease was also correlated with the extent of limbic and frontal gray matter volume decrease.

CONCLUSIONS

Our results support the hypothesis that limbic and frontal gray matter alterations could explain various psychiatric symptoms observed in PINK1 mutation carriers. Factors determining individual susceptibility to degeneration of certain brain areas remain to be elucidated in future studies.

Inter-individual differences in novelty-seeking behavior in rats predict differential responses to desipramine in the forced swim test

RATIONALE

Antidepressant medications are effective only in a subpopulation of patients with depression, and some patients respond to certain drugs, but not others. The biological bases for these clinical observations remain unexplained.

OBJECTIVE

To investigate individual differences in response to antidepressants, we have examined the effects of the norepinephrine reuptake inhibitor desipramine (DMI) and the selective serotonin reutake inhibitor fluoxetine (FLU) in the forced swim test (FST) in rats that differ in their emotional behavior.

METHODS

As response to novelty correlates with numerous other measures of emotionality and substance abuse, we contrasted animals that are high responders (HR) in a novel environment with animals that are low responders (LR) and asked whether the two groups exhibit differential responses to DMI (10mg/kg) and FLU (20mg/kg).

RESULTS

At the behavioral level, DMI caused a significant decrease in immobility in LR animals only, while FLU caused a significant reduction in immobility in both groups. Moreover, at the neural level, DMI treatment led to a decrease in FST-induced c-fos messenger RNA levels in medial prefrontal cortex (PFC) and paraventricular nucleus of the hypothalamus (PVN) in LR but not HR animals.

CONCLUSIONS

Taken together, our results suggest that the HR-LR model is a useful tool to investigate individual differences in responses to norepinephrine reuptake inhibitors (NRIs) and that a differential activation of PFC and/or PVN could underlie some of the inter-individual differences in the efficacy of NRIs.

Depressive Störungen

Das Spektrum depressiver Erkrankungen macht den Hauptteil affektiver Störungen aus und gehört mit einer Inzidenz von ca. 8–20% zu den häufigsten psychischen Erkrankungen. Depressionen werden nach wie vor zu selten einer adäquaten Therapie (Antidepressiva, störungsspezifische Psychotherapie wie z. B. kognitive Verhaltenstherapie) zugeführt.

Antidepressant-like effects of the CRF family peptides, urocortin 1, urocortin 2 and urocortin 3 in a modified forced swimming test in mice

Most of the evidence suggests that corticotropin-releasing hormone (CRH) is involved in mood disorders. The CRF receptors type 1 (CRF(1) receptors) elicit a stress response, and their natural and synthetic antagonists have been studied as possible drugs against depression, whereas CRF receptors type 2 (CRF(2) receptors) appear to alleviate the stress response and mediate anxiolytic action. Other CRF family peptides are urocortin 1 (Ucn 1), urocortin 2 (Ucn 2) and urocortin 3 (Ucn 3). Little is known about the action of Ucn 1, Ucn 2 and Ucn 3 on depressive disorders. Antidepressant-like effects of Ucn 1, Ucn 2 and Ucn 3 (0.13, 0.25 and 0.5 microg/2 microl, i.c.v.) were assayed in mice in a modified forced swimming test (FST). This modified FST predicts the clinical efficacy of an antidepressant drug through the scoring of immobility, climbing and swimming behavior. The study demonstrated that Ucn 1 had no action on any of parameters studied in the modified FST. Ucn 2 elicited antidepressive-like action by shortening the immobility time. Additionally Ucn 2 significantly increased the climbing and swimming times. Ucn 3 likewise displayed an antidepressive-like effect by shortening the immobility time, and increasing the climbing and swimming times. The results suggest that CRF(2) receptor stimulation by Ucn 2 or Ucn 3 leads to antidepressant-like action, but dual stimulation of the CRF(1) and CRF(2) receptors by Ucn 1 does not trigger antidepressant-like action in the modified mouse FST.