The role of neuropeptide-Y in nandrolone decanoate-induced attenuation of antidepressant effect of exercise

Possible role of exercise therapy on depression: Effector neurotransmitters as key players

About 280 million people suffer from depression as the most common neurological disorder and the most common cause of death worldwide. Exercise with serotonin released in the brain by the 5-HT3-IGF-1 mechanism can lead to antidepressant effects. Swimming exercise has antidepressant effects by increasing the sensitivity of serotonin 5-HT2 receptors and postsynaptic 5-HT1A receptors, increasing 5-HT and 5HIAA levels, increasing TPH and serotonin, and decreasing inflammatory levels of IFN-γ and TNF-α. Anaerobic and aerobic exercises increase beta-endorphin, enkephalin, and dynorphin and have antidepressant effects. Exercise by increasing dopamine, D1R, and D2R leads to the expression of BDNF and activation of TrkB and has antidepressant behavior. Exercise leads to a significant increase in GABAAR (γ2 and α2 subunits) and reduces neurodegenerative disorders caused by GABA imbalance through anti-inflammatory pathways. By increasing glutamate and PGC1α and reducing glutamatergic neurotoxicity, exercise enhances neurogenesis and synaptogenesis and prevents neurodegeneration and the onset of depression. Irisin release during exercise shows an important role in depression by increasing dopamine, BDNF, NGF, and IGF-1 and decreasing inflammatory mediators such as IL-6 and IL-1β. In addition, exercise-induced orexin and NPY can increase hippocampal neurogenesis and relieve depression. After exercise, the tryptophan to large neutral amino acids (TRP/LNAA) ratio and the tryptophan to branched-chain amino acids (BCAA) ratio increase, which may have antidepressant effects. The expression of M5 receptor and nAChR α7 increases after exercise and significantly increases dopamine and acetylcholine and ameliorates depression. It appears that during exercise, muscarinic receptors can reduce depression through dopamine in the absence of acetylcholine. Therefore, exercise can be used to reduce depression by affecting neurotransmitters, neuromodulators, cytokines, and/or neurotrophins.

Paternal Prenatal and Lactation Exposure to a High-Calorie Diet Shapes Transgenerational Brain Macro- and Microstructure Defects, Impacting Anxiety-Like Behavior in Male Offspring Rats

Prenatal exposure to high-energy diets (HED) increases the susceptibility to behavioral alterations in the male offspring. We addressed whether prenatal HED primes the transgenerational inheritance of structural brain changes impacting anxiety/depression-like behavior in the offspring. For this, we used female Wistar rats exposed to a HED [cafeteria (CAF) diet, n = 6] or chow [control (CON) n = 6] during development. Anxiety and depression-like behavior were evaluated in filial 1 (F1), filial 2 (F2), and filial 3 (F3) male offspring using the open field (OFT), elevated plus maze, novelty suppressed feeding (NSFT), tail suspension (TST), and forced swimming tests. Structural brain changes were identified by deformation-based morphometry (DBM) and diffusion tensor imaging using ex vivo MRI. We found that the F1, F2, and F3 offspring exposed to CAF diet displayed higher anxious scores including longer feeding latency during the NSFT, and in the closed arms, only F1 offspring showed longer stay on edges during the OFT versus control offspring. DBM analysis revealed that CAF offspring exhibited altered volume in the cerebellum, hypothalamus, amygdala, and hippocampus preserved up to the F3 generation of anxious individuals. Also, F3 CAF anxious exhibited greater fractional anisotropy and axial diffusivity (AD) in the amygdala, greater apparent diffusion coefficient in the corpus callosum, and greater AD in the hippocampus with respect to the control. Our results suggest that prenatal and lactation exposure to HED programs the transgenerational inheritance of structural brain changes related to anxiety-like behavior in the male offspring.

Economic, ecological, and health aspects of β-diketonate application in the process of water purification

Water pollution is a constant challenge for humanity. Sustainable economic development and environmental protection through a green economy structure provide the opportunity to project a model of scientific, social, and economic flows. Considering new chemical use in water treatment, we tested two β-diketonates that we previously synthesized in the reaction between methyl ketone and diethyl oxalate under basic conditions. For water treatment, we used the appropriate salts of the mentioned compounds due to better solubility in water. In cooperation with the partner organizations PUC (public utility companies) Kragujevac, LTD (Private Limited Company), "Rudnik," and FIAT (Fabbrica Italiana Automobili Torino), we conducted research on their wastewater treatment. The results appeared to be more convincing in practice than the conventional methods. As a result of the study, no negative effects exerted on living organisms were found. Therefore, we are on the right track for potential application in the treatment of drinking water. Appropriate β-diketonates were tested on twelve microorganisms (isolates from the wastewater and standard strains of bacteria and yeast). One of the two tested compounds showed promising antimicrobial activity. Further investigations showed that the tested compounds significantly reduce the concentration of heavy metals, which was confirmed by statistical calculations. Also, the main advantage of this method is a small volume of waste requiring disposal, no need for driving off excess moisture, used recyclability of the coagulants, reducing hazardous waste, and therefore reducing the costs for water treatment.

Kinetics of neuropeptide Y, catecholamines, and physiological responses during moderate and heavy intensity exercises

Neuropeptide Y 1-36 (NPY1-36) is a vasoconstrictor peptide co-secreted with norepinephrine (NE) by nerve endings during sympathetic activation. NPY1-36 potentiates NE action post-synaptically through the stimulation of the Y1 receptor, whereas its metabolite NPY3-36 resulting from DPP4 action activates Y2 presynaptic receptors, inhibiting NE and acetylcholine secretion. The secretions of NPY1-36 and NPY3-36 in response to sympathetic nervous system activation have not been studied due to the lack of analytical techniques available to distinguish them. We determined in healthy volunteers NPY1-36, NPY3-36 and catecholamine kinetics and how these neurotransmitters modulate the physiological stress response during and after moderate- and heavy-intensity exercises. Six healthy males participated in this randomized, double-blind, saxagliptin vs placebo crossover study. The volunteers performed an orthostatic test, a 30-min exercise at moderate intensity and a 15-min exercise at heavy intensity each followed by 50 min of recovery in two separate sessions with saxagliptin or placebo. Oxygen consumption (V̇O₂), ventilation and heart rate were continuously recorded. NE, epinephrine, NPY1-36 and NPY3-36 were quantified by tandem mass spectrometry. We found that exercise triggers NPY1-36 and NE secretion in an intensity-dependent manner and that NE returns faster to the baseline concentration than NPY1-36 after exercise. NPY3-36 rises during recovery parallel to the decline of NPY1-36. Saxagliptin reverses the NPY1-36/NPY3-36 ratio but does not affect hemodynamics, nor NPY1-36 and catecholamine concentrations. We found that NPY1-36 half-life is considerably shorter than previously established with immunoassays. NPY1-36 and NE secretions are finely regulated to prevent an excessive physiological Y1 stimulating response to submaximal exercise.

Loss of Microglial Insulin Receptor Leads to Sex-Dependent Metabolic Disorders in Obese Mice

Obesity and type 2 diabetes mellitus (T2DM) are highly prevalent disorders, associated with insulin resistance and chronic inflammation. The brain is key for energy homeostasis and contains many insulin receptors. Microglia, the resident brain immune cells, are known to express insulin receptors (InsR) and to be activated by a hypercaloric environment. The aim of this study was to evaluate whether microglial insulin signaling is involved in the control of systemic energy homeostasis and whether this function is sex-dependent. We generated a microglia-specific knockout of the InsR gene in male and female mice and exposed them to control or obesogenic dietary conditions. Following 10 weeks of diet exposure, we evaluated insulin tolerance, energy metabolism, microglial morphology and phagocytic function, and neuronal populations. Lack of microglial InsR resulted in increased plasma insulin levels and insulin resistance in obese female mice. In the brain, loss of microglial InsR led to a decrease in microglial primary projections in both male and female mice, irrespective of the diet. In addition, in obese male mice lacking microglial InsR the number of proopiomelanocortin neurons was decreased, compared to control diet, while no differences were observed in female mice. Our results demonstrate a sex-dependent effect of microglial InsR-signaling in physiology and obesity, and stress the importance of a heterogeneous approach in the study of diseases such as obesity and T2DM.

Exercise mimetics: harnessing the therapeutic effects of physical activity

Exercise mimetics are a proposed class of therapeutics that specifically mimic or enhance the therapeutic effects of exercise. Increased physical activity has demonstrated positive effects in preventing and ameliorating a wide range of diseases, including brain disorders such as Alzheimer disease and dementia, cancer, diabetes and cardiovascular disease. This article discusses the molecular mechanisms and signalling pathways associated with the beneficial effects of physical activity, focusing on effects on brain function and cognitive enhancement. Emerging therapeutic targets and strategies for the development of exercise mimetics, particularly in the field of central nervous system disorders, as well as the associated opportunities and challenges, are discussed.

Association between nandrolone and behavioral alterations: A systematic review of preclinical studies

BACKGROUND AND AIM

In recent years the expanding misuse of Nandrolone among non-athletes, particularly adolescent males is a prevalent global concern due to its adverse effects. This article provides a summary of the experimental studies to clarify the relationship between Nandrolone exposure and behavioral and cognitive performances.

MATERIALS AND METHODS

The present systematic review was conducted using PubMed, Embase and ScienceDirect databases, from 2000 to 2020, using the following key terms: Nandrolone AND Cognition, Nandrolone AND Learning, Nandrolone AND Memory, Nandrolone AND (Synaptic plasticity or Hippocampal synaptic plasticity), Nandrolone AND (Aggression or Aggressive-like behavior), Nandrolone AND (Anxiety or Anxiety-like behavior), Nandrolone AND (Depression or Depressive-like behavior).

RESULTS

33 qualified papers were selected from the 2498 sources found. Of the 33 cases, 32 (96.97%) were males while only 1 (3.03%) was female and male. From 33 selected articles 8 reported studies were related to spatial memory, 2 reported studies were related to avoidance memory, 11 studies reported information on synaptic plasticity, 11 reported studies were related to aggressive behavior, 8 reported studies were related to aggressive behavior and 6 reported studies were related to depression.

CONCLUSION

Nandrolone can change spatial ability, avoidance memory and hippocampal synaptic plasticity. Also, Nandrolone exposure produces variable effects on behavioral function such as aggression, depression and anxiety. This despite the fact that the results are contradictory. These discrepancies might be due to the differences in sex, age, dosage and treatment duration, and administration route. However, the negative results are more common than the published positive ones.

The Beneficial Role of Filipendula ulmaria Extract in Prevention of Prodepressant Effect and Cognitive Impairment Induced by Nanoparticles of Calcium Phosphates in Rats

Mineral components of dental composites are used in many medical and dental applications, including preventive, restorative, and regenerative dentistry. To evaluate the behavioural alterations induced by nanosized particles of novel dental composites, by means of depressive level and cognitive functions, experimental groups of rats were chronically administered with nanosized hydroxyapatite (HA), tricalcium phosphate (TCP), and amorphous calcium phosphate (ACP) with or without simultaneous application of Filipendula ulmaria L. (FU) methanolic extract. The significant prodepressant action was observed in groups solely treated with HA and ACP. Besides, prolonged treatment with ACP also resulted in a significant decline in cognitive functions estimated in the novel object recognition test. The adverse impact of calcium phosphates on estimated behavioural functions was accompanied by increased oxidative damage and apoptotic markers in the prefrontal cortex, as well as diminished specific neurotrophin (BDNF) and gabaergic expression. The results of our investigation showed that simultaneous antioxidant supplementation with FU extract prevented calcium phosphate-induced behavioural disturbances, as well as prooxidative and apoptotic actions, with the simultaneous restoration of BDNF and GABA-A receptors in the prefrontal cortex. These findings suggest that FU may be useful in the prevention of prodepressant impact and cognitive decline as early as the manifestation of calcium phosphate-induced neurotoxicity.

Neurobiological effects of forced swim exercise on the rodent hippocampus: a systematic review

Forced swimming is a common exercise method used for its low cost and easy management, as seen in studies with the hippocampus. Since it is applied for varied research purposes many protocols are available with diverse aspects of physical intensity, time and periodicity, which produces variable outcomes. In the present study, we performed a systematic review to stress the neurobiological effects of forced swim exercise on the rodent hippocampus. Behavior, antioxidant levels, neurotrophins and inflammatory markers were the main topics examined upon the swimming effects. Better results among these analyses were associated with forced exercise at moderate intensity with an adaptation period and the opposite for continuous exhausting exercises with no adaptation. On further consideration, a standard swimming protocol is necessary to reduce variability of results for each scenario investigated about the impact of the forced swimming on the hippocampus.

Forced swimming is a common exercise method used for its low cost and easy management, as seen in studies with the hippocampus. Since it is applied for varied research purposes many protocols are available with diverse aspects of physical intensity, time and periodicity, which produces variable outcomes. In the present study, we performed a systematic review to stress the neurobiological effects of forced swim exercise on the rodent hippocampus. Behavior, antioxidant levels, neurotrophins and inflammatory markers were the main topics examined upon the swimming effects. Better results among these analyses were associated with forced exercise at moderate intensity with an adaptation period and the opposite for continuous exhausting exercises with no adaptation. On further consideration, a standard swimming protocol is necessary to reduce variability of results for each scenario investigated about the impact of the forced swimming on the hippocampus.

Involvement of kynurenine pathway in depressive-like behaviour induced by nandrolone decanoate in mice

Nandrolone decanoate (ND) belongs to the class II of anabolic-androgenic steroids (AAS), which is composed of 19-nor-testosterone-derivatives. AAS represent a group of synthetic testosterone that is used in clinical treatment. However, these drugs are widely abused among individuals as a means of promoting muscle growth or enhancing athletic performance. AAS in general and ND in particular have been associated with several behavioral disturbances, such as anxiety, aggressiveness and depression. A factor that contributes to the development of depression is the brain activation of indoleamine 2,3-dioxygenase (IDO), the rate-limiting enzyme of kynurenine pathway (KP). In the present study, we examined the involvement of KP in depressive phenotype induced by a ND treatment (10 mg/kg/day/s.c., for 28 days) that mimics human abuse system (e.g. supraphysiological doses) in C57B/6J mice. Our results showed that ND caused depressive like-behavior in the tail suspension test and anhedonic-like state measured in the sucrose preference test. ND administration decreased the levels of brain-derived neurotrophic factor and neurotrophin-3 and reduced Na⁺,K⁺-ATPase activity in the hippocampus, striatum and prefrontal cortex. We also found that ND elicited KP activation, as reflected by the increase of IDO activity and kynurenine levels in these brain regions. Moreover, ND decreased serotonin levels and increased 5-hydroxyindoleacetic acid levels in the brain. Treatment with IDO inhibitor 1-methyl-dl-trypthophan (1 mg/kg/i.p.) reversed the behavioral and neurochemical alterations induced by ND. These results indicate for the first time that KP plays a key role in depressive-like behavior and neurotoxicity induced by supraphysiologicaldoses of ND in mice.

Prenatal Androgenization Induces Anxiety-Like Behavior in Female Rats, Associated with Reduction of Inhibitory Interneurons and Increased BDNF in Hippocampus and Cortex

Anxiety is one of the most frequent psychiatric disorders. Despite the fact that most studies describe an anxiolytic effect of testosterone, hyperandrogenemia in mothers is assumed to be related to an increased risk of mood disorders in their offspring. An increasing body of scientific evidence suggests that an altered expression of interneuronal markers of the hippocampus may be the cause of anxiety. The aim of this study was to examine the influence of maternal hyperandrogenemia on behavioral parameters of anxiety-like behavior, neuropeptide Y (NPY) and parvalbumin (PV) expression in the hippocampus, and the level of the brain-derived neurotrophic factor (BDNF) in the hippocampus and cerebral cortex. Pregnant female Wistar albino rats were treated with testosterone undecanoate on the 20th day of gestation. Anxiety-like behavior in adult female offspring was evaluated by the elevated plus maze test and the open field. The number of PV and NPY immunoreactive cells in the hippocampus was determined immunohistochemically. The level of BDNF expression in the hippocampus and cerebral cortex was analyzed with the Western blot test. Prenatal hyperandrogenization increased anxiety-like behavior in female offspring and decreased expression of NPY+ and PV+ in the CA1 region of the hippocampus as compared to the control group. BDNF expression in the hippocampus and cerebral cortex of prenatally androgenized female offspring was significantly increased in comparison with the controls. Prenatal hyperandrogenization may be the cause of anxiety-like behavior in female offspring. Decrease in NPY and PV expression in the hippocampus may explain the possible mechanism of hyperandrogenization induced anxiety.

The Benefits of Using New Tools for Behavioral Investigations in Animal Experimental Models

The animal experimental models of emotional disorders attempt to reproduce features of human psychiatric disorders in laboratory animals by correlating the physiological and behavioral changes associated with specific emotional states, the etiology of disorders, and responses on drug treatments. Animal experimental models that accurately recapitulate clinical pathology are indispensable for understanding molecular mechanisms and advancing preclinical studies. Behavioral tests on animal models have been developed over time in two directions: to enable the acquisition of as many valid behavior data as possible, and constructing experimental models and procedures that represent a parallel with certain conditions in humans. In this review we discuss more information for the new tools in behavioral investigations in animal experimental models. Here we described evoked beam-walking (EBW) test as a new test for estimation of anxiety levels. The reliability of that test was confirmed in our studies by using nandrolone decanoate (ND) and testosterone enanthate (TE) in supraphysiological doses. Also, we defined a new approach to estimation of exploratory activity by using these tests and an improvement of detectability in standard evaluation of depressive state levels. Taking into account that behavioral investigation in animal models still has to remain indispensable in conducting of preclinical studies, we assume that new tools that can be applied in this field may improve the quality of research.

Exercise Attenuates Anabolic Steroids-Induced Anxiety via Hippocampal NPY and MC4 Receptor in Rats

The aim of our study was to evaluate the effects of chronic administration of nandrolone-decanoate (ND) or testosterone-enanthate (TE) in supraphysiological doses and a prolonged swimming protocol, alone and in combination with ND or TE, on anxiety-like behavior in rats. We investigated the immunohistochemical alterations of the hippocampal neuropeptide Y (NPY) and melanocortin 4 receptor (MC4R) neurons, as a possible underlying mechanism in a modulation of anxiety-like behavior in rats. Both applied anabolic androgenic steroids (AASs) induced anxiogenic effect accompanied with decreased serum and hippocampal NPY. The exercise-induced anxiolytic effect was associated with increased hippocampal NPY expression. ND and TE increased the number of MC4R, while the swimming protocol was followed by the reduction of MC4R in the CA1 region of the hippocampus. However, NPY/MC4R ratio in hippocampus was lowered by AASs and elevated by exercise in all hippocampal regions. An augmentation of this ratio strongly and positively correlated to increased time in open arms of elevated plus maze, in the context that indicates anxiolytic effect. Our findings support the conclusion that alterations in both hippocampal NPY and MC4R expression are involved in anxiety level changes in rats, while their quantitative relationship (NPY/MC4R ratio) is even more valuable in the estimation of anxiety regulation than individual alterations for both NPY and MC4R expression in the hippocampus.

The Impact of Hippocampal Sex Hormones Receptors in Modulation of Depressive-Like Behavior Following Chronic Anabolic Androgenic Steroids and Exercise Protocols in Rats

The aim of this study was to evaluate alterations in depressive-like behaviors in rats following chronic administration of a supraphysiological dose of anabolic androgenic steroids (AASs) as well as exposure to a prolonged exercise protocol. The role of hippocampal sex hormones receptors in the modulation of depressive-like behavior was also assessed. A total of 48 male Wistar albino rats were divided into six groups: control, exercise (1 h/day, five consecutive days), nandrolone-decanoate (ND, 20 mg/kg/week, in a single dose), exercise plus ND, testosterone-enanthate (TE, 20 mg/kg/week, in a single dose), and exercise plus TE. After the 6-week protocols were complete, the rats underwent behavioral testing in the tail suspension test (TST). Rats were sacrificed for the collection of blood samples, to determine sex hormones levels, and isolation of the hippocampus, to determine [androgen receptors (AR) and estrogen receptors α (ERα)] expression. ND and TE treatment induced significant depressive-like behavior, opposing the antidepressant effect of exercise. Chronic TE administration elevated testosterone (T) and dihydrotestosterone (DHT) serum levels, and this was augmented by exercise. In contrast, ND and exercise alone did not alter T or DHT levels. There were no changes in serum estradiol levels in any of the groups. Immunohistochemical analysis showed that exercise reduced AR immunoreactivity in all hippocampal regions and increased the ERα expression in the CA1, dentate gyrus (DG), and total hippocampal sections, but not in the CA2/3 region. AASs administration increased AR expression in all hippocampal regions, although not the total hippocampal section in the TE group and did not significantly decrease ERα. The hippocampal AR/ERα expression index was lowered while parvalbumin (PV)-immunoreactivity was enhanced by exercise. AASs administration increased the AR/ERα index and reduced PV-immunoreactivity in the hippocampus. The number of PV-immunoreactive neurons negatively correlated with the antidepressant effects and the AR/ERα ratio. Our results suggest a potential role of the numerical relationship between two sex hormones receptors (stronger correlation than for each individual receptor) in the regulation of depressive-like behavior via the hippocampal GABAergic system in rats, which allow better understanding of the hippocampal sex hormones receptors role in modulation of depressive-like behavior.

The opposite effects of nandrolone decanoate and exercise on anxiety levels in rats may involve alterations in hippocampal parvalbumin-positive interneurons

The aim of this study was to evaluate the behavioral effects of chronic (six weeks) nandrolone decanoate (ND, 20 mg/kg, s.c., weekly in single dose) administration (in order to mimic heavy human abuse), and exercise (swimming protocol of 60 minutes a day, five days in a row/two days break), applied alone and simultaneously with ND, in male rats (n = 40). Also, we evaluated the effects of those protocols on hippocampal parvalbumin (PV) content and the possible connection between the alterations in certain parts of hippocampal GABAergic system and behavioral patterns. Both ND and exercise protocols induced increase in testosterone, dihydrotestosterone and estradiol blood levels. Our results confirmed anxiogenic effects of ND observed in open field (OF) test (decrease in the locomotor activity, as well as in frequency and cumulative duration in the centre zone) and in elevated plus maze (EPM) test (decrease in frequency and cumulative duration in open arms, and total exploratory activity), that were accompanied with a mild decrease in the number of PV interneurons in hippocampus. Chronic exercise protocol induced significant increase in hippocampal PV neurons (dentate gyrus and CA1 region), followed by anxiolytic-like behavioral changes, observed in both OF and EPM (increase in all estimated parameters), and in evoked beam-walking test (increase in time to cross the beam), compared to ND treated animals. The applied dose of ND was sufficient to attenuate beneficial effects of exercise in rats by means of decreased exercise-induced anxiolytic effect, as well as to reverse exercise-induced augmentation in number of PV immunoreactive neurons in hippocampus. Our results implicate the possibility that alterations in hippocampal PV interneurons (i.e. GABAergic system) may be involved in modulation of anxiety level induced by ND abuse and/or extended exercise protocols.