Monoamine Metabolism Research Articles

CDNF Exerts Anxiolytic, Antidepressant-like, and Procognitive Effects and Modulates Serotonin Turnover and Neuroplasticity-Related Genes.

Cerebral dopamine neurotrophic factor (CDNF) is an unconventional neurotrophic factor because it does not bind to a known specific receptor on the plasma membrane and functions primarily as an unfolded protein response (UPR) regulator in the endoplasmic reticulum. Data on the effects of CDNF on nonmotor behavior and monoamine metabolism are limited. Here, we performed the intracerebroventricular injection of a recombinant CDNF protein at doses of 3, 10, and 30 μg in C57BL/6 mice. No adverse effects of the CDNF injection on feed and water consumption or locomotor activity were observed for 3 days afterwards. Decreases in body weight and sleep duration were transient. CDNF-treated animals demonstrated improved performance on the operant learning task and a substantial decrease in anxiety and behavioral despair. CDNF in all the doses enhanced serotonin (5-HT) turnover in the murine frontal cortex, hippocampus, and midbrain. This alteration was accompanied by changes in the mRNA levels of the 5-HT1A and 5-HT7 receptors and in monoamine oxidase A mRNA and protein levels. We found that CDNF dramatically increased c-Fos mRNA levels in all investigated brain areas but elevated the phosphorylated-c-Fos level only in the midbrain. Similarly, enhanced CREB phosphorylation was found in the midbrain in experimental animals. Additionally, the upregulation of a spliced transcript of XBP1 (UPR regulator) was detected in the midbrain and frontal cortex. Thus, we can hypothesize that exogenous CDNF modulates the UPR pathway and overall neuronal activation and enhances 5-HT turnover, thereby affecting learning and emotion-related behavior.

Unraveling the Liver-Brain Axis: Resveratrol's Modulation of Key Enzymes in Stress-Related Anxiety.

Stress-related anxiety disorders and anxiety-like behavior in post-traumatic stress disorder (PTSD) are associated with altered neurocircuitry pathways, neurotransmitter systems, and the activities of monoamine and glucocorticoid-metabolizing enzymes. Resveratrol, a natural polyphenol, is recognized for its antioxidant, anti-inflammatory, and antipsychiatric properties. Previous studies suggest that resveratrol reduces anxiety-like behavior in animal PTSD models by downregulating key enzymes such as 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1) and monoamine oxidases (MAOs). However, the underlying mechanisms remain unclear. In this study, we explored the efficacy of resveratrol in treating stress-induced anxiety using a chronic predator stress model in rats. Resveratrol was administered intraperitoneally at 100 mg/kg following a 10-day stress exposure, and anxiety behavior was assessed with an elevated plus maze. Our results indicated that stress-related anxiety correlated with increased activities of brain MAO-A, MAO-B, and hepatic 11β-HSD-1, alongside elevated oxidative stress markers in the brain and liver. Resveratrol treatment improved anxiety behavior and decreased enzyme activities, oxidative stress, and hepatic damage. We demonstrate that resveratrol exerts antianxiogenic effects by modulating glucocorticoid and monoamine metabolism in the brain and liver. These findings suggest resveratrol's potential as a therapeutic agent for anxiety disorders, warranting further clinical investigation.

Monoamine oxidases activity maintains endometrial monoamine homeostasis and participates in embryo implantation and development

BackgroundMonoamine oxidases (MAOs) is an enzyme that catalyzes the deamination of monoamines. The current research on this enzyme is focused on its role in neuropsychiatric, neurodevelopmental, and neurodegenerative diseases. Indeed, MAOs with two isoforms, namely, A and B, are located on the outer mitochondrial membrane and are widely distributed in the central nervous system and peripheral tissues. Several reports have described periodic changes in the levels of this enzyme in the human endometrial tissue.ResultsThe novel role of MAOs in endometrial receptivity establishment and embryonic development by maintaining monoamine homeostasis was investigated in this study. MAOs activity was observed to be enhanced during the first trimester in both humans and mice under normal conditions. However, under pathological conditions, MAOs activity was reduced and was linked to early pregnancy failure. During the secretory phase, the endometrial stromal cells differentiated into decidual cells with a stronger metabolism of monoamines by MAOs. Excessive monoamine levels cause monoamine imbalance in decidual cells, which results in the activation of the AKT signal, decreased FOXO1 expression, and decidual dysfunction.ConclusionsThe findings suggest that endometrial receptivity depends on the maintenance of monoamine homeostasis via MAOs activity and that this enzyme participates in embryo implantation and development.

Antidepressant effect of new coumarin derivatives

BACKGROUND: The incidence of bipolar disorder is increasing worldwide. The search for new compounds with antidepressant activity and milder adverse drug reactions is an urgent task of modern psychopharmacology. AIM: This study aimed to analyze the effect of new neuroactive coumarin derivatives on the level of depressive behavior and monoamine metabolism in the brain structures of rats. MATERIALS AND METHODS: The antidepressant effects of LVM-091, LVM-099, LVM-S144, and IEM-2886 were evaluated in rats subjected to the Porsolt forced swimming test and the metabolism of monoamines in brain structures (LVM-099) using high-performance liquid chromatography. RESULTS: LVM-091, LVM-099, LVM-S144, and IEM-2886, synthesized from coumarin, decreased the immobilization time of the experimental rats in the Porsolt forced swimming test, indicating the antidepressant effect of these substances. The administration of LVM-099 at a dose of 10 mg/kg increased the level of homovanillic acid and the homovanillic acid-to-dopamine ratio in the nucleus accumbens. LVM-099 also increased 5-hydroxyindoleacetic acid levels and the 5-hydroxyindoleacetic acid-to-serotonin ratio in the nucleus accumbens. In the amygdala, the levels of norepinephrine, dopamine, serotonin, and their metabolites did not change after LVM-099 administration. CONCLUSIONS: New coumarin derivatives exert antidepressant effects and increase the metabolism of dopamine and serotonin in rat nucleus accumbens, which can be used in the development of new highly effective antidepressants.

Therapeutic Potential of Myricetin in the Treatment of Neurological, Neuropsychiatric, and Neurodegenerative Disorders.

Myricetin (MC), 3,5,7,3',4',5'-hexahydroxyflavone, chemically belongs to a flavonoid category known to confer antioxidant, antimicrobial, antidiabetic, and neuroprotective effects. MC is known to suppress the generation of Reactive Oxygen Species (ROS), lipid peroxidation (MDA), and inflammatory markers. It has been reported to improve insulin function in the human brain and periphery. Besides this, it modulates several neurochemicals including glutamate, GABA, serotonin, etc. MC has been shown to reduce the expression of the enzyme Mono Amine Oxidase (MAO), which is responsible for the metabolism of monoamines. MC treatment reduces levels of plasma corticosterone and restores hippocampal BDNF (full form) protein in stressed animals. Further, MC has shown its protective effect against amyloid-beta, MPTP, rotenone, 6-OHDA, etc. suggesting its potential role against neurodegenerative disorders. The aim of the present review is to highlight the therapeutic potential of MC in the treatment of several neurological, neuropsychiatric, and neurodegenerative disorders.

Effects of unilateral cortical inactivation on monoamine metabolism in symmetrical forebrain areas of white outbred mice

BACKGROUND: Clinical observations and animal experiments have shown the lateral specificity of the action of compounds that alter monoaminergic transmission. However, the mechanism of this phenomenon has not yet been studied.AIM:To evaluate the effect of unilateral cortical spreading depression on monoamine metabolism in white outbred mice. MATERIALS AND METHODS:Eighteen sexually mature male white outbred mice were studied. Functional inactivation of the cortex of one of the cerebral hemispheres was induced using unilateral epidural application of 1 × 1 mm filter paper moistened with 25% KCl solution. Then, 15 minutes after exposure, the animals were decapitated. The norepinephrine, dopamine, serotonin, and metabolite (i.e., dioxyphenylacetic (DOPAC), homovanilinic (HVA), and 5-hydroxyindolacetic (5-HIAA) acids) content of the cerebral cortex, hippocampus, olfactory tubercle, and striatum was measured using the HPLC method with an electrochemical detector. RESULTS: The inactivation of the left hemisphere was due to a bilateral decrease in norepinephrine in the hippocampus, an ipsilateral increase in extracellular metabolism of dopamine (HVA and/or HVA/dopamine) in the olfactory tubercle and striatum, and a contralateral increase of dopamine in the cortex and hippocampus. Furthermore, the DOPAC/dopamine ratio in the right olfactory tubercle decreased with left hemisphere inactivation. Right hemisphere inactivation did not cause bilateral effects. With inactivation of the right hemisphere on the inactivation side, norepinephrine in the hippocampus decreased and HVA in the striatum increased. In the left side, with the inactivation of the right hemisphere mice, dopamine in the hippocampus increased, as well as the DOPAC level and DOPAC/dopamine ratio in the olfactory tubercle. Serotonin metabolism (5-HIAA/serotonin) in the right hippocampus and left olfactory tubercle increased only at inactivation of the right hemisphere.CONCLUSIONS:The monoaminergic effects of functional inactivation of the left and right hemisphere cortex in white outbred mice are not mirror-symmetrical.

Psychic trauma causes increased impulsivity in a model of gambling addiction by altering dopamine and serotonin metabolism in the prefrontal cortex

BACKGROUND: Gambling addiction (gambling) involves frequently repeated episodes of gambling that are detrimental to social, professional, material, and family values. Gambling addiction is often combined with posttraumatic stress disorder.
 AIM: This study aimed to examine the effect of predator presentation stress on the manifestations of gambling addiction in an animal model in a test of probability and magnitude of reinforcement in the Iowa gambling task and monoamine metabolism in the prefrontal cortex of rats.
 MATERIALS AND METHODS: Rats were trained in a test of probability and magnitude of reinforcement in the Iowa gambling task in a 3-beam maze. Each run in arm 1 of the maze was reinforced with one sunflower seed, each second run in arm 2 with two seeds, and each third run in arm 3 with three seeds. Correspondingly, half of the runs in arm 2 and 2/3 of the runs in arm 3 were left unreinforced. After training, the animals were placed in a terrarium with a tiger python, one of which was victimized for its food requirements. On day 14 after predator presentation, dopamine and serotonin metabolism in the prefrontal cortex was determined using high-performance liquid chromatography with electrochemical detection.
 RESULTS: The levels of the dopamine metabolite dioxyphenylacetic acid and the ratio of dioxyphenylacetic acid to dopamine in the prefrontal cortex decreased. The levels of serotonin, its metabolite 5-hydroxyindoleacetic acid, and the ratio of 5-hydroxyindoleacetic acid to serotonin in the prefrontal cortex were also decreased in rats after exposure to a predator. Moreover, predator presentation induced significant behavioral changes in rats, increasing impulsivity in making choices in a test of probability and magnitude of reinforcement in the Iowa gambling task. The acute vital stress of predator presentation increased the number of escapes to arm 3 of the maze, suggesting that the animals exhibited more risky behavior when choosing reinforcements of different strengths and probability.
 CONCLUSIONS: The animal model showed that the depletion of the dopaminergic and serotoninergic systems of the prefrontal cortex underlies pathological gambling addiction and inadequate decision-making caused by posttraumatic stress disorder.

Mouse models for inherited monoamine neurotransmitter disorders.

Several mouse models have been developed to study human defects of primary and secondary inherited monoamine neurotransmitter disorders (iMND). As the field continues to expand, current defects in corresponding mouse models include enzymes and a molecular co-chaperone involved in monoamine synthesis and metabolism (PAH, TH, PITX3, AADC, DBH, MAOA, DNAJC6), tetrahydrobiopterin (BH4) cofactor synthesis and recycling (adGTPCH1/DRD, arGTPCH1, PTPS, SR, DHPR), and vitamin B6 cofactor deficiency (ALDH7A1), as well as defective monoamine neurotransmitter packaging (VMAT1, VMAT2) and reuptake (DAT). No mouse models are available for human DNAJC12 co-chaperone and PNPO-B6 deficiencies, disorders associated with recessive variants that result in decreased stability and function of the aromatic amino acid hydroxylases and decreased neurotransmitter synthesis, respectively. More than one mutant mouse is available for some of these defects, which is invaluable as different variant-specific (knock-in) models may provide more insights into underlying mechanisms of disorders, while complete gene inactivation (knock-out) models often have limitations in terms of recapitulating complex human diseases. While these mouse models have common phenotypic traits also observed in patients, reflecting the defective homeostasis of the monoamine neurotransmitter pathways, they also present with disease-specific manifestations with toxic accumulation or deficiency of specific metabolites related to the specific gene affected. This review provides an overview of the currently available models and may give directions toward selecting existing models or generating new ones to investigate novel pathogenic mechanisms and precision therapies.

Depressive Disorder in Primary Hyperparathyroidism and Effects of Surgery in Elderly Patients: Case Series

Background: Patients with primary hyperparathyroidism (PHPT) often present nonspecific symptoms such as major depressive disorder and psychosis. Calcium plays a role in the pathogenesis of psychiatric symptoms by determining changes in monoamine metabolism in the central nervous system, thereby modifying neurotransmission and resulting in mood and cognitive alterations. Case series: This report presents a case series of 3 patients; 70-year-old, 78 year- old and 94 year-old women with PHPT and severe depression symptoms and its response to parathyroidectomy. The patients were a poor historian. Results of preoperative laboratory tests showed an increased serum calcium level (11.15mg/dL, 10.9 mg/dL and 11.4 mg/dL- reference range 8.4-10.2 mg/dL). A repeat serum calcium test confirmed hypercalcemia with concurrent elevated intact parathyroid hormone level. Two patients were undergone at parathyroidectomy. A 94 year-old patient refuse surgical approach and was efficacy treated with a single dose of zoledronic acid. Therefore, the patients underwent parathyroidectomy two months after procedure had a clinical improvement on depressive symptoms. There was any recurrent laryngeal nerve injury or recurrent PHTP. Conclusion: The presence of a long-standing depressive disorder unresponsive to medical therapy may suggest an organic disorder such as chronic hypercalcemia which may be secondary to PHPT. Surgical intervention in these selected cases can assist medical therapy in the improvement of depressive symptoms.

Действие 1-метил-4-(4-фторфенил)- 1,2,3,6-тетрагидропиридина на биохимические показатели сыворотки крови и обмен моноаминов в головном мозге мышей

Changes in biochemical parameters of blood serum and monoamine metabolism in the brain were studied on male white outbred mice subjected to intraperitoneal injections of 1-methyl-4-(4-fluorophenyl)-1,2,3,6-tetrahydropyridine (MPTP-F). The levels of norepinephrine, dopamine, serotonin and their metabolites — dioxyphenylacetic, homovanilinic and 5-hydroxyindolacetic acids — were neasured by HPLC in the cerebral cortex, hippocampus, olfactory tubercle and striatum of the right and left sides of the brain. The treatement with MPTP-F did not lead to significant changes in the biochemical parameters of blood serum. An increase in the norepinephrine concentration a decrease in the dopamine level in the right striatum were found in animals treated with MPTP-F. No changes were detected in other studied brain areas. It has been suggested that the effect of the neurotoxin MPTP-F is determined by several factors, i. e. the lipophilic properties of the molecule, the quantitative distribution of dopamine neurons between right and left sides of the brain, differences in the linear velocity of blood flow through the right and left carotid arteries and the state of the blood-brain barrier. The results obtained may indicate the prospects of using MPTP-F for modeling the early stage of Parkinson’s disease.

Changes in monoamine metabolism in the brain during unilateral cortical spreading depression in BALB/c mice

BACKGROUND: BALB/c mice can be adequate models for elucidating the actions of neurotropic drugs in conditions of abnormal interhemispheric interactions.
 AIM: To examine the effect of unilateral cortical spreading depression on monoamine metabolism in BALB/c mice.
 MATERIALS AND METHODS: Twenty-four adult male BALB/c mice were analyzed. Unilateral cortical spreading depression (functional inactivation of one of the cerebral hemisphere cortex) was induced by applying a 1 × 1 mm filter paper moistened with a 25% KCl solution. Fifteen minutes after exposure, the animals were decapitated. By using high-performance liquid chromatography with an electrochemical detector in the cerebral cortex, hippocampus, olfactory tubercle, and striatum, the levels of norepinephrine (NE), dopamine (DA), serotonin (5-HT) and their metabolites (dioxyphenylacetic [DOPAC], homovanilinic [HVA] and 5-hydroxyindolacetic acids) were measured.
 RESULTS: Unilateral cortical spreading depression was accompanied by a decrease in NE levels in the hippocampus and an increase in the DA extracellular metabolism (HVA and/or HVA/DA) in the olfactory tubercle and striatum on the side of the inactivated cortex. In addition to the listed effects, only functional inactivation of the right hemisphere caused a bilateral decrease in the NE level in the cortex and a decrease in the NE level and the DOPAC/DA ratio in the left (contralateral) hippocampus. No regular changes were noted in the posture of animals after the unilateral inactivation of the cerebral cortex.
 CONCLUSION:The results suggest that in BALB/c mice, the right hemisphere cortex plays a dominant role in regulating the activity of the noradrenergic system in the brain.

DNAJC12 in Monoamine Metabolism, Neurodevelopment, and Neurodegeneration.

Recent studies show that pathogenic variants in DNAJC12, a co-chaperone for monoamine synthesis, may cause mild hyperphenylalaninemia with infantile dystonia, young-onset parkinsonism, developmental delay and cognitive deficits. DNAJC12 has been included in newborn screening, most revealingly in Spain, and those results highlight the importance of genetic diagnosis and early intervention in combating human disease. However, practitioners may be unaware of these advances and it is probable that many patients, especially adults, have yet to receive molecular testing for DNAJC12. Hence, this review summarizes genotype-phenotype relationships and treatment paradigms for patients with pathogenic variants in DNAJC12. It provides an overview of the structure of DNAJC12 protein, known genetic variants, domains, and binding partners, and elaborates on its role in monoamine synthesis, disease etiology, and pathogenesis. © 2023 International Parkinson and Movement Disorder Society.

SMN deficiency perturbs monoamine neurotransmitter metabolism in spinal muscular atrophy

Beyond motor neuron degeneration, homozygous mutations in the survival motor neuron 1 (SMN1) gene cause multiorgan and metabolic defects in patients with spinal muscular atrophy (SMA). However, the precise biochemical features of these alterations and the age of onset in the brain and peripheral organs remain unclear. Using untargeted NMR-based metabolomics in SMA mice, we identify cerebral and hepatic abnormalities related to energy homeostasis pathways and amino acid metabolism, emerging already at postnatal day 3 (P3) in the liver. Through HPLC, we find that SMN deficiency induces a drop in cerebral norepinephrine levels in overt symptomatic SMA mice at P11, affecting the mRNA and protein expression of key genes regulating monoamine metabolism, including aromatic L-amino acid decarboxylase (AADC), dopamine beta-hydroxylase (DβH) and monoamine oxidase A (MAO-A). In support of the translational value of our preclinical observations, we also discovered that SMN upregulation increases cerebrospinal fluid norepinephrine concentration in Nusinersen-treated SMA1 patients. Our findings highlight a previously unrecognized harmful influence of low SMN levels on the expression of critical enzymes involved in monoamine metabolism, suggesting that SMN-inducing therapies may modulate catecholamine neurotransmission. These results may also be relevant for setting therapeutic approaches to counteract peripheral metabolic defects in SMA.

Alterations in Serotonin Neurotransmission in Hyperdopaminergic Rats Lacking the Dopamine Transporter.

Biogenic amines dopamine (DA) and serotonin (5-HT) are among the most significant monoaminergic neurotransmitters in the central nervous system (CNS). Separately, the physiological roles of DA and 5-HT have been studied in detail, and progress has been made in understanding their roles in normal and various pathological conditions (Parkinson's disease, schizophrenia, addiction, depression, etc.). In this article we showed that knockout of the gene encoding DAT leads not only to a profound dysregulation of dopamine neurotransmission in the striatum but also in the midbrain, prefrontal cortex, hippocampus, medulla oblongata and spinal cord. Furthermore, significant changes were observed in the production of mRNA of enzymes of monoamine metabolism, as well as to a notable alteration in the tissue level of serotonin, most clearly manifested in the cerebellum and the spinal cord. The observed region-specific changes in the tissue levels of serotonin and in the expression of dopamine and serotonergic metabolism enzymes in rats with an excess of dopamine can indicate important consequences for the pharmacotherapy of drugs that modulate the dopaminergic system. The drugs that affect the dopaminergic system could potently affect the serotonergic system, and this fact is important to consider when predicting their possible therapeutic or side effects.

Dopaminergic and serotoninergic neurotoxicity of lanthanide phosphate (TbPO4) in developing zebrafish

Rare earth elements (REEs) are exploited for global use in manufacturing. Such activities result in their release into the environment and the transformation into more stable phosphate deposition. The objective of this study was to evaluate molecular and behavioral changes of zebrafish exposed to the synthesized terbium phosphate (TbPO4) at concentrations of 10, 20, and 50 mg/L and to determine its potential for neurotoxicity. Metabolomics related to neurotransmitters, and assessment of transcripts and proteins were conducted to uncover the molecular mechanisms underlying TbPO4 with emphasis on neurotransmitter systems. Exposure to 20 mg/L TbPO4 induced larval hyperactivity and perturbed the cholinergic system in zebrafish. Based on metabolomics related to neurotransmitters, dopamine (DA), serotonin (5-HT), and many of their precursors and metabolites were decreased in abundance by TbPO4. In addition, the expression levels of transcripts related to the synthesis, transport, receptor binding, and metabolism of DA and 5-HT were analyzed at the mRNA and protein levels. Transcript and protein levels for tyrosine hydroxylase (TH), the rate-limiting enzyme for DA synthesis, were down-regulated in larval fish. Monoamine oxidase (MAO), an enzyme that catabolizes monoamines DA and 5-HT, was also reduced in mRNA abundance. We hypothesize that DA synthesis and monoamine metabolism are associated with behavioral alterations. This study elucidates putative mechanisms and exposure risks to wildlife and humans by characterizing phosphatic REE-induced neurotoxicity in developing zebrafish.

Prenatal SAMe Treatment Changes via Epigenetic Mechanism/s USVs in Young Mice and Hippocampal Monoamines Turnover at Adulthood in a Mouse Model of Social Hierarchy and Depression.

The role of hippocampal monoamines and their related genes in the etiology and pathogenesis of depression-like behavior, particularly in impaired sociability traits and the meaning of changes in USVs emitted by pups, remains unknown. We assessed the effects of prenatal administration of S-adenosyl-methionine (SAMe) in Sub mice that exhibit depressive-like behavior on serotonergic, dopaminergic and noradrenergic metabolism and the activity of related genes in the hippocampus (HPC) in adulthood in comparison to saline-treated control Sub mice. During postnatal days 4 and 8, we recorded and analyzed the stress-induced USVs emitted by the pups and tried to understand how the changes in the USVs' calls may be related to the changes in the monoamines and the activity of related genes. The recordings of the USVs showed that SAMe induced a reduction in the emitted flat and one-frequency step-up call numbers in PND4 pups, whereas step-down type calls were significantly increased by SAMe in PND8 pups. The reduction in the number of calls induced by SAMe following separation from the mothers implies a reduction in anxiety, which is an additional sign of decreased depressive-like behavior. Prenatal SAMe increased the concentrations of serotonin in the HPC in both male and female mice without any change in the levels of 5HIAA. It also decreased the level of the dopamine metabolite DOPAC in females. There were no changes in the levels of norepinephrine and metabolites. Several changes in the expression of genes associated with monoamine metabolism were also induced by prenatal SAMe. The molecular and biochemical data obtained from the HPC studies are generally in accordance with our previously obtained data from the prefrontal cortex of similarly treated Sub mice on postnatal day 90. The changes in both monoamines and their gene expression observed 2-3 months after SAMe treatment are associated with the previously recorded behavioral improvement and seem to demonstrate that SAMe is effective via an epigenetic mechanism.

Iron Deficiency Anaemia: The Psychological Menace.

Madam, As per the World Health Organisation, anaemia is the condition of having an inadequate number of red blood cells or if the concentration of haemoglobin in them is reduced. Haemoglobin is a complex protein component of RBCs that carries oxygen around the body, a deficiency that can lead the person to experience fatigue, dyspnoea, weakness, dizziness etc.1 Such an ailment is bound to make daily life activities difficult and take a toll on one’s mental health. The WHO approximates that anaemia is prevalent in two billion people world-wide. There are many reasons for anaemia, including nutritional deficiencies, menstruation, stomach ulcers, parasitic infections, chronic illnesses and haemoglobinopathies etc. Nutritional deficits are the most common cause of anaemia, among which iron deficiency is namely the guiltiest, accounting for half of the total cases world-wide. It is a global public health travesty, especially for children and pregnant women.1 A vital component in the synthesis of the haemoglobin molecule is iron. Haemoglobin that is iron-deprived produces hypochromic and microcytic red blood cells. Iron is associated with several neurological functions, a deficiency of which leads to poor myelination of the white matter as well as a disturbance in monoamine metabolism. Additionally, fluctuations in the levels of brain iron interfere with the homeostasis of neurotransmitters such as gamma-aminobutyric acid and glutamate. Enzymes for synthesising neurotransmitters like dopamine and serotonin- essential in the modification of mood, anxiety, and other emotional behaviours- require iron as a vital component.2 Abnormalities in the physiology of these neurochemicals due to disruptions in an adequate iron supply will undoubtedly increase the likelihood of associated disorders, including but not limited to depression, anxiety, sleeping issues, developmental and emotional afflictions etc. A research paper comparing the risk of various psychiatric illnesses in patients with iron deficiency anaemia and healthy controls concluded the IDA group at a higher risk for developing anxiety, depression, sleep disruption, and psychotic disorders. Interestingly, it also found t that IDA with iron supplementation reported remarkably lower risks of psychiatric disturbances.3 It is, thus, necessary to monitor iron levels in anaemic individuals and where needed, introduce supplements to reduce the risk of developing and/or progression of psychiatric disorders. Further studies are also required to better expound on the relationship between iron deficiency anaemia and psychiatric illnesses.

Monoaminergic effects of the unilateral blockade of orexin receptors (OX1R) in the enlarged amygdala under psychostimulant action

BACKGROUND: The search for new drugs potentially effective in stopping the development of pathological addictions is an urgent task of experimental psychopharmacology.
 AIM: To examine the participation of brain monoaminergic systems in the mechanisms of the blocking effect of SB-408124 on the self-stimulation of the lateral hypothalamus activated with the psychostimulant -phenylisopropylamine (PIPA) treatment.
 MATERIALS AND METHODS: Male Wistar rats pre-administered with psychostimulant (PIPA, 1 mg/kg intraperitoneally) were unilaterally injected with an orexin antagonist SB-408124 (1 g in 1 L) into the central nucleus of the amygdala or the bed nucleus of the stria terminalis (BNST). High-performance liquid chromatography with electrochemical detection was used to determine the levels of monoamines and their metabolites: norepinephrine (NA), dopamine (DA), serotonin (5-HT), dioxyphenylacetic (DOPAC), homovaniline (HVA), and 5-hydroxyindolacetic (5-HIAA) acids on the left and right sides of the prefrontal cortex, hippocampus, striatum, and olfactory tubercle.
 RESULTS: Under the action of PIPA, microinjections of SB-408124 into the right central nucleus of the amygdala induced the following effects: prefrontal cortex, an increase in the levels of HVA and 5-HT on the right side and 5-HIAA on the left; hippocampus, bilateral increase in the levels of NA and HVA and 5-HT on the right; striatum, bilateral increase in the level of DA and the left-sided increase in HVA, 5-HT, and 5-HIAA. Microinjections into the left central nucleus of the amygdala caused a right-sided decrease in NA levels, an increase in 5-HT levels, and a left-sided decrease in DA and DOPAC levels in the striatum and a left-sided increase in HVA level in the olfactory tubercle. Microinjections into the right BNST caused a left-sided decrease in the levels of NA and DA in the prefrontal cortex, bilateral decrease in DOPAC levels, a right-sided increase in 5-HT levels, and a left-sided increase in 5-HIAA levels in the striatum; and a left-sided increase in HVA levels in the olfactory tubercle. Microinjections into the left BNST caused increased 5-HT levels in the left striatum and decreased DOPAC and 5-HIAA levels in the left olfactory tubercle.
 CONCLUSIONS: Right-sided microinjections cause a greater number of changes in monoamine metabolism than left-sided ones. The introduction of SB-408124 into the right structures of the enlarged amygdala increases 5-HIAA levels in the left striatum, whereas microinjections in BNST lead to increased 5-HT levels in the ipsilateral striatum and in the contralateral in the central nucleus of the amygdala

Active vs passive novelty-related strategies: Sex differences in exploratory behaviour and monoaminergic systems

Sex differences are apparent in numerous behavioural characteristics. In order to compare and characterise male and female variability of exploratory behaviour, 365 male and 401 female rats were assessed in a task where a bimodal response distribution had previously been established in males. Female rats had significantly higher exploratory activity, and presented normal distribution of the behaviour, very differently from the bimodal distribution of males. No major effect of litter or oestrous cycle was detected. Several differences between male and female rats were found in monoamine metabolism measured ex vivo. Male rats had lower levels of dopamine (DA) in frontal cortex, and higher levels of 3,4-dihydroxyphenylacetic acid (DOPAC) in raphe area; higher levels of serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in dorsal striatum but lower levels of 5-HT and 5-HIAA in locus coeruleus area, 5-HIAA levels were also lower in hippocampus as compared to females. Males had higher noradrenaline (NA) levels in hippocampus and lower normetanephrine (NMN) levels in striatum, in both brain regions male animals had lower NMN/NA ratio. No sex difference was found in accumbens. The only brain region with an interaction between sex and the expression of exploratory activity was raphe: Here 5-HT levels were lower, and DOPAC levels and DOPAC/DA and 5-HIAA/5-HT ratios higher in low exploring male but not female rats. Conclusively, female rats not only display higher levels of exploration but the population distribution of this behaviour is distinct; this may be related to differences in the monoaminergic systems between female and male animals.

EXPLORATION OF PYRAZOLINE AND AMINO CHALCONE DERIVATIVES AS MONOAMINE OXIDASE INHIBITORS: AN IN-SILICO APPROACH

Monoamine oxidase (MAO) is an enzyme involved in neurotransmitter monoamine metabolism through an oxidative deamination reaction that produces a nerve-damaging substance, H2O2. Two isoforms of MAO that are MAO-A, and MAO-B, are known by their specific substrates, serotonin, and dopamine, respectively. Overexpression of MAO-A causes depression and anxiety disorder, whereas MAO-B causes neurodegenerative disorders such as Parkinson’s and Alzheimer’s. Infections and diseases caused by the activity of these two enzymes are known to affect millions of people worldwide every year. Various drugs for both disorders are available on the market. However, side effects such as dizziness, sore throat, insomnia, obesity, and heart disorder are registered. Therefore, developing new compounds acting as MAO inhibitors with lower side effects but higher selectivity than available drugs is in need. Pyrazolines and amino chalcone derivatives are well known to exhibit inhibition of MAO activity and used as research objects. Virtual screening of molecular docking using DOCK6 of six compounds of each pyrazoline (1a-f) (both R and S configuration) and amino chalcone (2a-f) was conducted to study their inhibition activity to MAO-A (PDB: 2Z5X) and MAO-B (PDB: 6FW0) and selectivity based on comparison of grid score value of Harmin as control positive for MAO-A and E92 ligand for MAO-B. The results showed that the most potent compound as a selective inhibitor of MAO is (R)-3-(4-aminophenyl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carboxamide of pyrazoline derivative and (1- (4-cinnamoyl phenyl) thiourea) of amino chalcone derivative.