Venlafaxine plus melatonin ameliorate reserpine-induced depression-like behavior in zebrafish

Fluoxetine rescues the depressive-like behaviour induced by reserpine and the altered emotional behaviour induced by nicotine withdrawal in zebrafish: Involvement of tyrosine hydroxylase

BACKGROUND

Nicotine cessation leads to anxiety and depression.

AIMS

The suitability of the zebrafish model of anhedonia using reserpine and fluoxetine was evaluated. Fluoxetine was also used to reduce nicotine withdrawal-induced anhedonic state.

METHODS

Zebrafish were exposed to reserpine (40 mg/l) and then to fluoxetine (0.1 mg/l) for 1 week. Anhedonia was evaluated in the Novel Tank Diving and Compartment Preference tests. Another group was exposed to nicotine (1 mg/l/2 weeks) and then exposed to fluoxetine. Anxiety and anhedonia were evaluated 2-60 days after. Tyrosine hydroxylase (TH) immunoreactivity and microglial morphology (labelled by 4C4 monoclonal antibody) in the parvocellular pretectal nucleus (PPN), dorsal part, and of calcitonin gene-related peptide (CGRP) in the hypothalamus were also analysed.

RESULTS

Less time in the top and increased latency to the top in reserpine compared to a drug-free group was found. Fluoxetine rescued reserpine-induced the reduced time in the top. Seven and 30 days after nicotine withdrawal more time in the bottom and similar time in the Compartment Preference test, rescued by fluoxetine, were shown. In the PPN, 30-day withdrawal induced an increase in TH immunoreactivity, but fluoxetine induced a further significant increase. No changes in PPN microglia morphology and hypothalamic CGRP were detected.

CONCLUSIONS

Our findings validate the suitability of the zebrafish model of anhedonia using the reserpine-induced depression-like behaviour and the predictivity using fluoxetine. Fluoxetine rescued nicotine withdrawal-induced anhedonic state, opening the possibility to screen new drugs to alleviate anxiety and depression in smokers during abstinence.

Integrate transcriptomic and metabolomic analysis reveals the underlying mechanisms of behavioral disorders in zebrafish (Danio rerio) induced by imidacloprid

Imidacloprid, a widely used neonicotinoid insecticide, poses a significant threat to aquatic ecosystems. Behavior is a functional indicator of the net sensory, motor, and integrative processes of the nervous system and is presumed to be more sensitive in detecting toxicity. In the present study, we investigated the behavioral effects of imidacloprid at the level of environmental concentrations (1, 10 and 100 μg/L) for a constant exposure to zebrafish adults, and performed the integrated transcriptomic and metabolomic analysis to analyze the molecular mechanism underlying behavioral effects of imidacloprid. Our results show that imidacloprid exposure significantly induce behavioral disruptions characterized by anxiety, depression, and reduced physiological function including exploratory, decision, social interaction and locomotor activity. Integrated transcriptomic and metabolomic analysis indicate that the disruption of circadian rhythm, metabolic imbalance of arginine and proline, and neurotransmitter disorder are the underlying molecular mechanisms of behavioral impairment induced by imidacloprid. The "gene-metabolite-disease" network consisted by 11 metabolites and 15 genes is associated human disease Alzheimer's disease (AD) and schizophrenia. Our results confirm the behavioral impairment induced by imidacloprid at environmental concentrations for constant exposure. The identified genes and metabolites can be used not only to illustrate the underlying mechanisms, but also can be developed as biomarkers in determining the ecological risk of imidacloprid to aquatic organisms even Homo sapiens.

Chronic exposure to environmentally relevant concentrations of carbamazepine interferes with anxiety response of adult female zebrafish through GABA /5-HT pathway and HPI axis

Carbamazepine (CBZ) is one of the widely distributed pharmaceutical residues in aquatic environments, yet few researches have addressed its chronic effect on the anxiety of fish, and the mechanisms possibly involved remained elusive. In this study, adult female zebrafish (Danio rerio) were exposed to environmental relevant concentrations of CBZ (CBZ-low, 10 μg/L; CBZ-high, 100 μg/L) for 28 days. After exposure, CBZ-high didn't affect the anxiety of fish. However, the onset time to the higher half of the tank was delayed and the total duration in the lower half of the tank was increased in CBZ-low fish, suggesting an increased anxiety. Further investigation indicated that CBZ-low significantly decreased the gamma-aminobutyric acid (GABA) level in the brain, while increased the serotonin (5-HT) level in the brain and cortisol level in plasma. Accordingly, the mRNA levels of genes in GABA (gad2, abat, gabrb2, gabrg2, gria1a and slc12a2) pathway and HPI (crha, actha, pc1 and pc2) axis were also altered. Despite the upregulation of tph2 was consistent with increased 5-HT level in the brain, significantly downregulated htr1aa and htr1b may indicate attenuated 5-HT potency. Although CBZ-high significantly reduced GABA level in the brain and increased cortisol level in plasma, the effects were dramatically alleviated than that of CBZ-low. Consistently, the expression of genes in HPI (crha, actha, pc1 and pc2) axis and GABA (gad2 and abat) pathway were also altered by CBZ-high, probably due to inconspicuous anxiety response of CBZ-high. Briefly, our data suggested that low concentration of CBZ disrupted zebrafish anxiety by interfering with neurotransmission and endocrine system, thereby bringing about adverse ecological consequences.

Alpha-lipoic acid-role in improving both reserpine toxicity and paroxetine treatment in the cerebral cortex of albino rats; histological, ultrastructural, immunohistohemical and biochemical studies

Background

Reserpine is a monoamine depletory drug cause oxidative damage and used to induce depression-like features in rodent model. Paroxetine is an antidepressant drug that exerts its effects by inhibiting dopaminergic neurons although it may exert much pathological damage. Alpha-lipoic acid (ALA) is an endogenous antioxidant co-factor of important enzymatic complexes. The present study was aimed to elucidate the possible protective effect of ALA in the improvement of the deleterious cerebral cortex injury after reserpine and paroxetine treatment. Forty adult male albino rats were equally divided into 5 groups. Group I served as control group orally treated with saline solution all the experiment period. Group II animals orally treated with ALA (200 mg/kg/day) for six weeks. The induction of depression-like features occurred when the rest of animals were intraperitoneally treated with 25 mg/kg of reserpine once daily for consecutive 14 day. Then these animals were divided into; Group III (reserpine group) animals in this group were sacrificed on 15th day. Group IV; reserpine-treated animals were treated with paroxetine (20 mg/kg) daily for 6 weeks. Group V, animals in this group were received paroxetine and ALA daily for 6 weeks.

Results

Reserpine-treated rats showed disorganized layers of cerebral cortex with degenerative, apoptotic and necrotic changes. Ultrastructure changes include both pyramidal and granule cells with severe degenerative, necrotic and apoptotic features. The nuclei appeared pyknotic; irregular with chromatin condensation as well as the cytoplasm of these cells contained many degenerated organelles. In addition, a significant increase in total oxidative stress and decrease in total antioxidant capacity, norepinephrine, dopamine and serotonin levels were recorded. The same treatment showed significant decrease in proliferating cell nuclear antigen (PCNA) expression and significant increase in caspase-3 expression in the granule and pyramidal cells. After paroxetine-treatment these parameters were more or less similar to those observed in reserpine-treated ones. While an obvious improvement was appeared when animal treated with both paroxetine and ALA and; all parameters restored its normal features.

Conclusions

This study concluded that; ALA treatment attenuated the cerebral injury induced by reserpine and improved the effects of paroxetine in rats due to its anti-inflammatory, anti-apoptotic and antioxidant activities.

Mahonia Alkaloids (MA) Ameliorate Depression Induced Gap Junction Dysfunction by miR-205/Cx43 Axis

Depression has become an important disease threatening human health. In recent years, the efficacy of Traditional Chinese Medicine (TCM) in treating the disease has become increasingly prominent, so it is meaningful to find new antidepressant TCM. Mahonia fortune (Lindl.) Fedde is a primary drug in traditional formulas for the treatment of depression, and alkaloids are the main components of it. However, the detailed mechanism of Mahonia alkaloids (MA) on depression remains unclear. This study aimed to investigate the effect of MA on gap junction function in depression via the miR-205/Cx43 axis. The antidepressant effects of MA were observed by a rat model of reserpine-induced depression and a model of corticosterone (CORT)-induced astrocytes. The concentrations of neurotransmitters were measured by ELISA, the expression of Connexin 43 (Cx43) protein was measured by Immunohistochemistry and western-blot, brain derived neurotrophic factor (BDNF), cAMP-response element binding protein (CREB) proteins were measured by western-blot, the pathological changes of prefrontal cortex were observed by hematoxylin-eosin (H&E) staining. Luciferase reporter assay was performed to verify the binding of miR-205 and Cx43. The regulation effect of Cx43 on CREB was verified by interference experiment. Gap junction dysfunction was detected by fluorescent yellow staining. The results confirmed that MA remarkably decreased miR-205 expression and increased Cx43, BDNF, CREB expression in depression rat and CORT-induced astrocytes. In addition, after overexpression of miR-205 in vitro, the decreased expression of Cx43, BDNF and CREB could be reversed by MA. Moreover, after interfering with Cx43, the decreased expression of CREB and BDNF could be reversed by MA. Thus, MA may ameliorate depressive behavior through CREB/BDNF pathway regulated by miR-205/Cx43 axis.

Neurotoxicity of sanguinarine via inhibiting mitophagy and activating apoptosis in zebrafish and PC12 cells

Sanguinarine, a plant-derived phytoalexin, displays various biological activities, such as insecticidal, antimicrobial, anti-inflammatory, anti-angiogenesis and antitumor effects. But its potential neurotoxicity and the underlying mechanisms has rarely been investigated. Therefore, we aimed to assess the neurotoxicity of sanguinarine using zebrafish model and PC12 cells in this study. The results showed that sanguinarine induced the reduction of the length of dopamine neurons and inhibited the blood vessel in the head area of the zebrafish. Further studies demonstrated that the behavioral phenotype of the larval zebrafish was changed by sanguinarine. In addition, there were more apoptotic cells in the larval zebrafish head area. The mRNA expression levels of β-syn, th, pink1 and parkin, closely related to the nervous function, were changed after sanguinarine treatment. The in vitro studies show that notably increases of ROS and apoptosis levels in PC12 cells were observed after sanguinarine treatment. Moreover, the protein expression of Caspase3, Parp, Bax, Bcl2, α-Syn, Th, PINK1 and Parkin were also altered by sanguinarine. Our data indicated that the inhibition of mitophagy, ROS elevation and apoptosis were involved in the neurotoxicity of sanguinarine. These findings will be useful to understand the toxicity induced by sanguinarine.

Physical exercise prevents behavioral alterations in a reserpine-treated zebrafish: A putative depression model

Major depressive disorder (MDD) has increasingly reached the world population with an expressive increase in recent years due to the COVID-19 pandemic. Here we used adult zebrafish (Danio rerio) as a model to verify the effects of reserpine on behavior and neurotransmitter levels. We observed an increase in the immobile time and time spent in the bottom zone of the tank in reserpine-exposed animals. The results demonstrated a decrease in distance traveled and velocity. Reserpine exposure did not induce changes in memory and social interaction compared to the control group. We also evaluated the influence of exposure to fluoxetine, a well-known antidepressant, on the behavior of reserpine-exposed animals. We observed a reversal of behavioral alterations caused by reserpine. To verify whether behavioral alterations in the putative depression model induced by reserpine could be prevented, the animals were subjected to physical exercise for 6 weeks. The results showed a protective effect of the physical exercise against the behavioral changes caused by reserpine in zebrafish. In addition, we observed a reduction in dopamine and serotonin levels and an increase in the 3,4-dihydroxyphenylacetic acid (DOPAC) levels in the brain. Physical exercise was able to prevent the changes in dopamine and serotonin levels, reinforcing that the preventive effect promoted by physical exercise is related to the modulation of neurotransmitter levels. Our findings showed that reserpine was effective in the induction of a putative depression model in zebrafish and that physical exercise may be an alternative to prevent the effects induced by reserpine.

Early-Stage High-Concentration Thiacloprid Exposure Induced Persistent Behavioral Alterations in Zebrafish

As a major neonicotinoid insecticide, thiacloprid (THCP) is frequently detected in aquatic environments worldwide due to its heavy use, posing potential threats to aquatic organisms. In this study, zebrafish (Danio rerio) embryos were exposed to THCP (1, 10, 100, 1000 and 10,000 μg/L) for 5 days and then recovered in THCP-free water for 20 days to investigate the effects of early-stage THCP exposure on the development, antioxidant defense, and neurotransmitter systems of zebrafish, and explore their recovery mechanism. The results show that THCP exposure induced developmental toxicity and oxidative stress in zebrafish. The hypoactivity, behavioral alterations (decreased avoidance and edge preference behaviors) and neurotoxicity were found throughout the exposure-recovery experiments. THCP exposure altered the expression of γ-aminobutyric acid (GABA)- and serotonin (5-HT)-related genes accompanied by the decrease in GABA and 5-HT contents. However, after recovery, GABA content returned to the control level, but 5-HT did not, indicating that only the serotonergic system was persistently disrupted. Overall, our results suggest that the disruption of the serotonergic system and oxidative stress may aggravate neurotoxicity and that the former was the main reason for the depressive-like behavior. This study could help to unravel the mechanisms of the behavioral alterations induced by early-stage THCP exposure in zebrafish.

The food preservative sodium propionate induces hyperglycaemic state and neurological disorder in zebrafish

Propionate is an effective mould inhibitor widely used as a food preservative. In this study, we used zebrafish to explore the adverse effects of long-term exposure to low concentrations of sodium propionate and the underlying molecular mechanisms (from larvae to adult). When exposed for 3 months, we found that blood glucose, total cholesterol, and triglyceride levels increased, and zebrafish developed a hyperglycaemic state. New tank test results showed depression in zebrafish reduced 5-hydroxytryptamine levels in the brain and damaged the dopamine system. At the same time, the results of the color preference test showed that zebrafish had cognitive impairments. In addition, Hypothalamic-Pituitary-Adrenal axis analysis revealed abnormal gene expression, increased cortisol levels, and reduced glucocorticoid receptor mRNA levels, which were consistent with depressive behavior. We also observed abnormal transcription of inflammatory and apoptotic factors. Overall, we found that chronic exposure to sodium propionate induces depressive symptoms. This may be related to the activation of the HPA axis by the hyperglycaemic state, thereby inducing inflammation and disrupting the dopaminergic system. In summary, this study provides theoretical and technical support for the overlap of the emotional pathogenesis associated with diabetes.

Beyond the behavioural phenotype: Uncovering mechanistic foundations in aquatic eco-neurotoxicology

During the last decade, there has been an increase in awareness of how anthropogenic pollution can alter behavioural traits of diverse aquatic organisms. Apart from understanding profound ecological implications, alterations in neuro-behavioural indices have emerged as sensitive and physiologically integrative endpoints in chemical risk assessment. Accordingly, behavioural ecotoxicology and broader eco-neurotoxicology are becoming increasingly popular fields of research that span a plethora of fundamental laboratory experimentations as well as applied field-based studies. Despite mounting interest in aquatic behavioural ecotoxicology studies, there is, however, a considerable paucity in deciphering the mechanistic foundations underlying behavioural alterations upon exposure to pollutants. The behavioural phenotype is indeed the highest-level integrative neurobiological phenomenon, but at its core lie myriads of intertwined biochemical, cellular, and physiological processes. Therefore, the mechanisms that underlie changes in behavioural phenotypes can stem among others from dysregulation of neurotransmitter pathways, electrical signalling, and cell death of discrete cell populations in the central and peripheral nervous systems. They can, however, also be a result of toxicity to sensory organs and even metabolic dysfunctions. In this critical review, we outline why behavioural phenotyping should be the starting point that leads to actual discovery of fundamental mechanisms underlying actions of neurotoxic and neuromodulating contaminants. We highlight potential applications of the currently existing and emerging neurobiology and neurophysiology analytical strategies that should be embraced and more broadly adopted in behavioural ecotoxicology. Such strategies can provide new mechanistic discoveries instead of only observing the end sum phenotypic effects.

Ameliorative effect of Gastrodia elata Blume extracts on depression in zebrafish and cellular models through modulating reticulon 4 receptors and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Gastrodia elata Blume (G. elata), a traditional Chinese herb, known as "Tian Ma", is widely used as a common medicine and diet ingredient for treating or preventing neurological disorders for thousands of years in China. However, the anti-depressant effect of G. elata and the underlying mechanism have not been fully evaluated.

AIM OF THE STUDY

The study is aimed to investigate the anti-depressant effect and the molecular mechanism of G. elata in vitro and in vivo using PC12 cells and zebrafish model, respectively.

MATERIAL AND METHODS

Network pharmacology was performed to explore the potential active ingredients and action targets of G. elata Blume extracts (GBE) against depression. The cell viability and proliferation were determined by MTT and EdU assay, respectively. TUNEL assay was used to examine the anti-apoptotic effect of GBE. Immunofluorescence and Western blot were used to detect the protein expression level. In addition, novel tank diving test was used to investigate the anti-depressant effect in zebrafish depression model. RT-PCR was used to analyze the mRNA expression levels of genes.

RESULTS

G. elata against depression on the reticulon 4 receptors (RTN4R) and apoptosis-related targets, which were predicted by network pharmacology. Furthermore, GBE enhanced cell viability and inhibited the apoptosis in PC12 cells against CORT treatment. GBE relieved depression-like symptoms in adult zebrafish, included increase of exploratory behavior and regulation of depression related genes. Mechanism studies showed that the GBE inhibited the expression of RTN4R-related and apoptosis-related genes.

CONCLUSION

Our studies show the ameliorative effect of G. elata against depression. The mechanism may be associated with the inhibition of RTN4R-related and apoptosis pathways.

Effect of aerobic exercise as a treatment on type 2 diabetes mellitus with depression-like behavior zebrafish

BACKGROUND

Depression is the most known complication of type 2 diabetes mellitus (T2DM). Aerobic exercise improves glycemic control in T2DM, although the underlying mechanisms of comorbid depression-like behaviors in T2DM have not yet been fully elucidated.

METHODS

120 zebrafish were randomly assigned to four groups: Control, T2DM, T2DM + metformin, and T2DM + aerobic exercise. Then, all animals except the control group were fed with high glucose fairy shrimp (~40 g/kg/day) and exposed reserpine (40 μg/ml for 20 min) for 10 days. Here, behavioral tests were used for model verification. Following the verification, all groups were treated as before. Additionally, the T2DM + metformin group received metformin (~10.6 mg/kg/day) at the same time, while the T2DM + aerobic exercise group received aerobic exercise 30 min/day. Finally, blood glucose and behavioral tests, as well as protein and molecular levels were determined at Day 11 and 12.

RESULTS

Aerobic exercise alleviated depressive-like behavior and enhanced the levels of antidepressant biomarkers (NE, 5-HIAA) in zebrafish after 10 consecutive days of exercise. Additionally, 10 consecutive days of aerobic exercise decreased the levels of inflammatory biomarkers (IFN-γ, IL-1, IL-4) and depressive biomarkers (cortisol). Meanwhile, it also aided in the reduction of CD11b, IL-6, IL-6R, and caspase-3 expression to combat the neuroinflammation induced by T2DM, mediated the BDNF-TrkB pathway, and increased Bcl-2/Bax levels.

CONCLUSION

Given the remarkable similarity in neurochemistry between humans and zebrafish, this study supports the effectiveness of aerobic exercise as clinical guidance in preventing and treating T2DM complicated with depression.

Towards translational modeling of behavioral despair and its treatment in zebrafish

Depression is a widespread and severely debilitating neuropsychiatric disorder whose key clinical symptoms include low mood, anhedonia and despair (the inability or unwillingness to overcome stressors). Experimental animal models are widely used to improve our mechanistic understanding of depression pathogenesis, and to develop novel antidepressant therapies. In rodents, various experimental models of 'behavioral despair' have already been developed and rigorously validated. Complementing rodent studies, the zebrafish (Danio rerio) is emerging as a powerful model organism to assess pathobiological mechanisms of depression and other related affective disorders. Here, we critically discuss the developing potential and important translational implications of zebrafish models for studying despair and its mechanisms, and the utility of such aquatic models for antidepressant drug screening.

Antidepressant actions of melatonin and melatonin receptor agonist: Focus on pathophysiology and treatment

Depression has become one of the most commonly prevalent neuropsychiatric disorders, and the main characteristics of depression are sleep disorders and melatonin secretion disorders caused by circadian rhythm disorders. Abnormal endogenous melatonin alterations can contribute to the occurrence and development of depression. However, molecular mechanisms underlying this abnormality remain ambiguous. The present review summarizes the mechanisms underlying the antidepressant effects of melatonin, which is related to its functions in the regulation of the hypothalamic-pituitary-adrenal axis, inhibition of neuroinflammation, inhibition of oxidative stress, alleviation of autophagy, and upregulation of neurotrophic, promotion of neuroplasticity and upregulation of the levels of neurotransmitters, etc. Also, melatonin receptor agonists, such as agomelatine, ramelteon, piromelatine, tasimelteon, and GW117, have received considerable critical attention and are highly implicated in treating depression and comorbid disorders. This review focuses on melatonin and various melatonin receptor agonists in the pathophysiology and treatment of depression, aiming to provide further insight into the pathogenesis of depression and explore potential targets for novel agent development.

Phenotype-Based HPLC-Q-TOF-MS/MS Coupled With Zebrafish Behavior Trajectory Analysis System for the Identification of the Antidepressant Components in Methanol Extract of Anshen Buxin Six Pills

Phenotype screening has become an important tool for the discovery of active components in traditional Chinese medicine. Anshen Buxin Six Pills (ASBX) are a traditional Mongolian medicine used for the treatment of neurosis in clinical settings. However, its antidepressant components have not been explicitly identified and studied. Here, the antidepressant effect of ASBX was evaluated in adult zebrafish. High performance liquid chromatography-mass spectrometry (HPLC-Q-TOF-MS/MS) was combined with zebrafish behavior trajectory analysis to screen and identify the antidepressant-active extract fraction and active components of ASBX. Finally, the antidepressant effect of the active ingredients were verified by the behavior, pathology, biochemical indices and protein level of adult fish. The novel tank driving test (NTDT) showed that ASBX can effectively improve the depressive effect of reserpine on zebrafish. Petroleum ether and dichloromethane extracts of ASBX were screened as antidepressant active extracts. Costunolide (COS) and dehydrocostus lactone (DHE) were screened as the active components of ASBX. COS had been shown to significantly improve the depressive behavior, nerve injury and neurotransmitter levels (5-hydroxytryptamine (5-HT) and norepinephrine (NE)) of zebrafish by inhibiting the high expression of serotonin transporter and norepinephrine transporter induced by reserpine suggesting the antidepressant effect of COS may be related to its effect on 5-HT and NE pathways. This study provided a phenotype based screening method for antidepressant components of traditional Chinese medicines, so as to realize the separation, identification and activity screening of components at the same time.

Fish self-awareness: limits of current knowledge and theoretical expectations

Animal self-awareness is divided into three levels: bodily, social, and introspective self-awareness. Research has focused mainly on the introspection of so-called higher organisms such as mammals. Herein, we turn our attention to fish and provide opinions on their self-awareness based on a review of the scientific literature. Our specific aims are to discuss whether fish (A) could have a neural substrate supporting self-awareness and whether they display signs of (B) social and (C) introspective self-awareness. The present knowledge does not exclude the possibility that fish could have a simple neocortex or other structures that support certain higher cognitive processes, as the function of the primate cerebral cortex can be replaced by other neurological structures. Fish are known to display winner, loser, and audience effects, which could be interpreted as signs of social self-awareness. The audience effect may be explained not only by ethological cost and benefit theory but also by the concept of public self-awareness, which comes from human studies. The behavioural and neural manifestations of depression may be induced in fish under social subordination and may be viewed as certain awareness of a social status. The current findings on fish introspective self-awareness have been debated in the scientific community and, therefore, demand replication to provide more evidence. Further research is needed to verify the outlined ideas; however, the current knowledge indicates that fish are capable of certain higher cognitive processes, which raises questions and implications regarding ethics and welfare in fish-related research and husbandry.

A Reliable High-Throughput Screening Model for Antidepressant

Depression is the most frequent affective disorder and is the leading cause of disability worldwide. In order to screen antidepressants and explore molecular mechanisms, a variety of animal models were used in experiments, but there is no reliable high-throughput screening method. Zebrafish is a common model organism for mental illness such as depression. In our research, we established chronic unpredictable mild stress (CUMS) models in C57BL/6 mice and zebrafish; the similarities in behavior and pathology suggest that zebrafish can replace rodents as high-throughput screening organisms. Stress mice (ip., 1 mg/kg/d, 3 days) and zebrafish (10 mg/L, 20 min) were treated with reserpine. As a result, reserpine caused depression-like behavior in mice, which was consistent with the results of the CUMS mice model. Additionally, reserpine reduced the locomotor ability and exploratory behavior of zebrafish, which was consistent with the results of the CUMS zebrafish model. Further analysis of the metabolic differences showed that the reserpine-induced zebrafish depression model was similar to the reserpine mice model and the CUMS mice model in the tyrosine metabolism pathway. The above results showed that the reserpine-induced depression zebrafish model was similar to the CUMS model from phenotype to internal metabolic changes and can replace the CUMS model for antidepressants screening. Moreover, the results from this model were obtained in a short time, which can shorten the cycle of drug screening and achieve high-throughput screening. Therefore, we believe it is a reliable high-throughput screening model.

Zebrafish as an Animal Model for Testing Agents with Antidepressant Potential

Depression is a serious mental disease that, according to statistics, affects 320 million people worldwide. Additionally, a current situation related to the COVID-19 pandemic has led to a significant deterioration of mental health in people around the world. So far, rodents have been treated as basic animal models used in studies on this disease, but in recent years, Danio rerio has emerged as a new organism that might serve well in preclinical experiments. Zebrafish have a lot of advantages, such as a quick reproductive cycle, transparent body during the early developmental stages, high genetic and physiological homology to humans, and low costs of maintenance. Here, we discuss the potential of the zebrafish model to be used in behavioral studies focused on testing agents with antidepressant potential.