Neurochemical Data Research Articles

Classical psychedelics’ action on brain monoaminergic systems

The study of the mechanism of action of classical psychedelics has gained significant interest due to their clinical potential in the treatment of several psychiatric conditions, including major depressive and anxiety disorders. These drugs bind 5-hydroxytryptamine receptors (5-HTR) including 5-HT1AR, 5-HT2AR, 5-HT2BR, and/or 5-HT2CR, as well as other targets. 5-HTRs regulate the activity of ascending monoaminergic neurons, a mechanism primarily involved in the action of classical antidepressant drugs, antipsychotics, and drugs of abuse. Sparse neurochemical data have been produced on the control of monoaminergic neuron activity in response to classical psychedelics. Here we review the available data in order to determine whether classical psychedelics have specific neurochemical effects on serotonergic, dopaminergic, and noradrenergic neurons. The data show that these drugs have disparate effects on each monoaminergic system, demonstrating a complex response with state-dependent and region-specific effects. For instance, several psychedelics inhibit the firing of serotonergic neurons, although this is not necessarily associated with a decrease in serotonin release in all regions. Noradrenergic neuron spontaneous activity also appears to be inhibited by psychedelics, also not necessarily associated with a decrease in noradrenaline release in all regions. Psychedelics influence on dopaminergic systems is also complex as the above-mentioned 5-HTRs may have opposing effects on dopaminergic neuron activity, in a state-dependent manner. There is an apparent lack of clear neuronal signature induced by psychedelics on monoaminergic neuron activity despite specific recurrent mechanisms. This review provides a current summary of the action of psychedelics on monoamine neuromodulators serotonin, dopamine and noradrenaline, compiling reoccurring and contradictory findings demonstrating that a monoamine signature of psychedelics, if applicable, would be state- and region-dependant.

Hominin musical sound production: palaeoecological contexts and self domestication

In this article we seek to integrate theories of music origins and dance with hominin fossil anatomy and the paleoecological contexts of hominin evolution. Based on the association between rhythm in music, dance and locomotion, we propose that early bipedal hominins may have evolved neurobiological substrates different from other great apes due to the rhythmic aspects of bipedal walking and running. Combined with the emancipation of the hands resulting from erect posture, we propose that the neurobiological changes necessary for technological innovation, cultural practices and human musical abilities may have evolved, at least in incipient form, much earlier than previously thought. The consequent ability to synchronize movement and sound production may have also proved beneficial as early bipedal hominins ventured out of late Miocene and early Pliocene woodland and forested habitats and into more open habitats with increased predation risk. We also postulate that, along with bipedalism, paedomorphic morphogenesis of the skull at the base of the hominin clade was a necessary prerequisite for the evolution of vocal modulation and singing in later varieties of hominin. To date research into the evolution of music and dance has yet to be integrated with the fossil and paleoecological evidence of early hominin evolution. This paper seeks to fill this lacuna in the extant literature on human evolution. We also suggest that autocatalytic feedback loops evolving synergistically with hominin erect posture, skull and hand morphology, neurochemical processes and the self-domestication syndrome, have been operative from early hominins some 6 Ma to the present. We document this process by reference to primatological, ethnographic, neurochemical and archaeological data.

A candidate projective neuron type of the cerebellar cortex: the synarmotic neuron.

Previous studies on the granular layer of the cerebellar cortex have revealed a wide distribution of different subpopulations of less-known large neuron types, called "non-traditional large neurons", which are distributed in three different zones of the granular layer. These neuron types are mainly involved in the formation of intrinsiccircuits inside the cerebellar cortex. A subpopulation of these neuron types is represented by the synarmotic neuron, which could play a projective role within the cerebellar circuitry. The synarmotic neuron cell body map within the internal zone of the granular layer or in the subjacent white substance. Furthermore, the axon crosses the granular layer and runs in the subcortical white substance, to reenter in an adjacent granular layer, associating two cortico-cerebellar regions of the same folium or of different folia, or could project to the intrinsic cerebellar nuclei. Therefore, along with the Purkinje neuron, the traditional projective neuron type of the cerebellar cortex, the synarmotic neuron is candidate to represent the second projective neuron type of the cerebellar cortex. Studies of chemical neuroanatomy evidenced a predominant inhibitory GABAergic nature of the synarmotic neuron, suggesting that it may mediate an inhibitory GABAergic output of cerebellar cortex within cortico-cortical interconnections or in projections towards intrinsic cerebellar nuclei. On this basis, the present minireview mainly focuses on the morphofunctional and neurochemical data of the synarmotic neuron, and explores its potential involvement in some forms of cerebellar ataxias.

Nano polystyrene induced changes in anxiety and learning behaviour are mediated through oxidative stress and gene disturbance in mouse brain regions

It is widely reported now that nanoplastic particles have potential neurotoxic effects and may disturb central nervous system (CNS) function. However, the mechanism behind these toxic effects still needs to be elucidated. In the current study, we investigated the effects of polystyrene nanoplastics (PS-NPs) on changes in learning, memory, and anxiety-related behavior in mice based on some selected biochemical, molecular, and histopathological changes in three important brain regions (Cortex, Hypothalamus, and Hippocampus). Male mice were orally administered daily with two doses of 50 nm PS-NPs (0.2 mg/ml and 1 mg/ml) for 8 weeks. We observed decreased expression of neurotransmitter-related genes (VAChT, GAD, and SYP) in the cortex, hypothalamus, and hippocampus areas of the mouse brain. Other biochemical variables including, antioxidant enzymes, biomarkers for oxidative stress, and acetylcholinesterase activity showed significant alterations in all three brain regions. Molecular and neurochemical data thus suggest significant neurobehavioral changes following sub-chronic exposure to PS-NPs which may lead to enhanced anxiety-related and spatial learning and memory-related impairments by affecting limbic areas of the brain.

SWADESH: a multimodal multi-disease brain imaging and neuropsychological database and data analytics platform.

Multimodal neuroimaging data of various brain disorders provides valuable information to understand brain function in health and disease. Various neuroimaging-based databases have been developed that mainly consist of volumetric magnetic resonance imaging (MRI) data. We present the comprehensive web-based neuroimaging platform "SWADESH" for hosting multi-disease, multimodal neuroimaging, and neuropsychological data along with analytical pipelines. This novel initiative includes neurochemical and magnetic susceptibility data for healthy and diseased conditions, acquired using MR spectroscopy (MRS) and quantitative susceptibility mapping (QSM) respectively. The SWADESH architecture also provides a neuroimaging database which includes MRI, MRS, functional MRI (fMRI), diffusion weighted imaging (DWI), QSM, neuropsychological data and associated data analysis pipelines. Our final objective is to provide a master database of major brain disease states (neurodegenerative, neuropsychiatric, neurodevelopmental, and others) and to identify characteristic features and biomarkers associated with such disorders.

Understanding the Significance of the Hypothalamic Nature of the Subthalamic Nucleus.

The subthalamic nucleus (STN) is an essential component of the basal ganglia and has long been considered to be a part of the ventral thalamus. However, recent neurodevelopmental data indicated that this nucleus is of hypothalamic origin which is now commonly acknowledged. In this work, we aimed to verify whether the inclusion of the STN in the hypothalamus could influence the way we understand and conduct research on the organization of the whole ventral and posterior diencephalon. Developmental and neurochemical data indicate that the STN is part of a larger glutamatergic posterior hypothalamic region that includes the premammillary and mammillary nuclei. The main anatomic characteristic common to this region involves the convergent cortical and pallidal projections that it receives, which is based on the model of the hyperdirect and indirect pathways to the STN. This whole posterior hypothalamic region is then integrated into distinct functional networks that interact with the ventral mesencephalon to adjust behavior depending on external and internal contexts.

Analgesic effect of central relaxin receptor activation on persistent inflammatory pain in mice: behavioral and neurochemical data.

The relaxin peptide signaling system is involved in diverse physiological processes, but its possible roles in the brain, including nociception, are largely unexplored. In light of abundant expression of relaxin receptor (RXFP1) mRNA/protein in brain regions involved in pain processing, we investigated the effects of central RXFP1 activation on nociceptive behavior in a mouse model of inflammatory pain and examined the neurochemical phenotype and connectivity of relaxin and RXFP1 mRNA-positive neurons. Mice were injected with Complete Freund Adjuvant (CFA) into a hind paw. After 4 days, the RXFP1 agonist peptides, H2-relaxin or B7-33, ± the RXFP1 antagonist, B-R13/17K-H2, were injected into the lateral cerebral ventricle, and mechanical and thermal sensitivity were assessed at 30 to 120 minutes. Relaxin and RXFP1 mRNA in excitatory and inhibitory neurons were examined using multiplex, fluorescent in situ hybridization. Relaxin-containing neurons were detected using immunohistochemistry and their projections assessed using fluorogold retrograde tract-tracing. Both H2-relaxin and B7-33 produced a strong, but transient, reduction in mechanical and thermal sensitivity of the CFA-injected hind paw alone, at 30 minutes postinjection. Notably, coinjection of B-R13/17K-H2 blocked mechanical, but not thermal, analgesia. In the claustrum, cingulate cortex, and subiculum, RXFP1 mRNA was expressed in excitatory neurons. Relaxin immunoreactivity was detected in neurons in forebrain and midbrain areas involved in pain processing and sending projections to the RXFP1-rich, claustrum and cingulate cortex. No changes were detected in CFA mice. Our study identified a previously unexplored peptidergic system that can control pain processing in the brain and produce analgesia.

Acquisition of a spatial navigation task in the padding pool induces an increase of GABA level in the hippocampus of Swiss mice

The balance between excitatory and inhibitory glutamatergic and GABAergic systems, respectively, is crucial for the maintenance of complex cognitive functions such as learning. Using Swiss mice as experimental model, the aims of the present study were to evaluate cognitive performance in a shallow water maze (SWM) and the effects of training in this spatial navigation task on hippocampal GABA and glutamate levels. In addition, correlations between neurochemical and behavioural data, and between glutamate and GABA levels were assessed. Forty-six three-month-old mice were divided into three groups: Learning, n=18: animals submitted to the SWM task; Active, n=14: animals exposed to the SWM, without the demand of performing a cognitive task and Control, n=14: the animals were kept in the vivarium without contact with the SWM. There was significant training effect indicating that the Learning group animals have learned the task. Regarding neurochemical data, the findings of the present work show for the first time that the task learning process in SWM has a significant effect on GABA levels in the hippocampus. The relationship between the two neurotransmitters, observed in the control animals, was adjusted by a significant increase in hippocampal GABA levels caused by the spatial training performed by the animals from the Learning group. However, the relationship observed in control condition is disrupted by a subsequent exposure to the maze in the absence of a spatial cognitive demand, as was the case of the Active group. These data open new perspectives to explore the involvement of the inhibitory and excitatory systems in the molecular mechanisms associated with different types and steps of learning processes.

The role of the anterior pretectal nucleus in pain modulation: A comprehensive review.

Descending pain modulation involves multiple encephalic sites and pathways that range from the cerebral cortex to the spinal cord. Behavioral studies conducted in the 1980s revealed that electrical stimulation of the pretectal area causes antinociception dissociation from aversive responses. Anatomical and physiological studies identified the anterior pretectal nucleus and its descending projections to several midbrain, pontine, and medullary structures. The anterior pretectal nucleus is morphologically divided into a dorsal part that contains a dense neuron population (pars compacta) and a ventral part that contains a dense fiber band network (pars reticulata). Connections of the two anterior pretectal nucleus parts are broad and include prominent projections to and from major encephalic systems associated with somatosensory processes. Since the first observation that acute or chronic noxious stimuli activate the anterior pretectal nucleus, it has been established that numerous mediators participate in this response through distinct pathways. Recent studies have confirmed that at least two pain inhibitory pathways are activated from the anterior pretectal nucleus. This review focuses on rodent anatomical, behavioral, molecular, and neurochemical data that have helped to identify mediators of the anterior pretectal nucleus and pathways related to its role in pain modulation.

Context-Specific Tolerance and Pharmacological Changes in the Infralimbic Cortex-Nucleus Accumbens Shell Pathway Evoked by Ketamine.

Like other drugs, ketamine is abused due to its ability to act as a positive reinforcer in the control of behavior, just as natural reinforcers do. Besides, through Pavlovian conditioning, tolerance to drug effects can become conditioned to specific contextual cues showing that environmental stimuli can act as powerful mediators of craving and relapse. In the present study, we shall investigate the effects of long-term ketamine administration and withdrawal on behavioral measures and emotionality, the drug-context-specific influence on the tolerance to the sedative effects of an anesthetic dose of ketamine, and the neuropharmacological events underlying this phenomenon, in rats conditioned with 10mg/kg of ketamine and later challenged with a dose of ketamine of 80mg/kg in a familiar and non-familiar environment. Variations in dopamine and serotonin efflux in the infralimbic cortex-nucleus accumbens shell circuitry (IL-NAcSh) was further recorded in the same conditions. Our results highlight that besides its well-known reinforcing properties, ketamine also shares the ability to induce behavioral and pharmacological conditioned tolerance, associated with increases in cortical (IL), and decreases in striatal (NAcSh) dopamine release. To our knowledge, we are presenting the first set of behavioral and neurochemical data showing that, like other drugs of abuse, ketamine can induce learned context-specific tolerance.

Do indices of baroreflex failure and peripheral noradrenergic deficiency predict the magnitude of orthostatic hypotension in Lewy body diseases?

Patients with neurogenic orthostatic hypotension in the setting of Lewy body diseases (LBnOH) typically have baroreflex failure and peripheral noradrenergic deficiency. Either or both of these abnormalities might determine the magnitude of OH in individual patients. We retrospectively correlated the orthostatic fall in systolic blood pressure (∆BPs) during active standing or 5min of head-up tilt at 90° from horizontal as a function of several baroreflex and sympathetic noradrenergic indices. Physiological, neurochemical, and sympathetic neuroimaging data from the Valsalva maneuver, head-up tilt table testing, and thoracic 18F-dopamine positron emission tomographic scanning (18F-DA PET) were analyzed from 72 patients with LBnOH [44 with Parkinson disease (PD) and nOH, 28 with pure autonomic failure]. Comparison subjects had PD without OH (N = 44) or PD risk factors without parkinsonism or OH (N = 28) or were healthy volunteers (N = 8). Indices of baroreflex function included the Valsalva maneuver-associated baroreflex areas in Phase II (BRA-II) and IV (BRA-IV), the pressure recovery time (PRT), and baroreflex-cardiovagal and adrenergic sensitivities (BRS-V and BRS-A). The fractional orthostatic increment in plasma norepinephrine (Fx∆NE) provided a neurochemical index of baroreflex-sympathoneural function. As expected, the LBnOH group had baroreflex-sympathoneural and baroreflex-cardiovagal impairment and low cardiac 18F-DA-derived radioactivity. Among patients, values for ∆BPs correlated with BRA-II, BRA-IV, BRS-V, and Fx∆NE but not with values for PRT, BRS-A, supine plasma NE, or 18F-DA-derived radioactivity. Across individual patients with LBnOH, quantitative indices of baroreflex dysfunctions and peripheral noradrenergic deficiency are inconsistently associated with the magnitude of OH, even under controlled laboratory conditions.

Modulation of Noradrenergic and Serotonergic Systems by Cannabinoids: Electrophysiological, Neurochemical and Behavioral Evidence.

The main noradrenergic and serotonergic nuclei in the central nervous system (CNS) are the locus coeruleus (LC) and the dorsal raphe nucleus (DRN). These brain areas, located in the brainstem, play a pivotal role in the control of various functions and behaviors that are altered by cannabinoids (i.e., pain, arousal, mood, anxiety, or sleep-wake cycle). Anatomical, neurochemical, and functional data suggest that cannabinoids regulate both central noradrenergic and serotonergic neurotransmission. Thus, strong evidence has shown that the firing activity of LC and DRN monoamine neurons or the synthesis/release of noradrenaline (NA) and serotonin (5-HT) in the projection areas are all affected by cannabinoid administration. Herein, we propose that interaction between the endocannabinoid system and the noradrenergic-serotonergic systems could account for some of the anxiolytic, antidepressant, and antinociceptive effects of cannabinoids or the disruption of attention/sleep induced by these drugs.

Cardioselective peripheral noradrenergic deficiency in Lewy body synucleinopathies.

ObjectiveLewy body (LB) synucleinopathies such as Parkinson’s disease (PD) entail profound cardiac norepinephrine deficiency. The status of sympathetic noradrenergic innervation at other extracranial sites has been unclear. Although in vivo neuroimaging studies have indicated a cardioselective noradrenergic lesion, no previous study has surveyed peripheral organs for norepinephrine contents in LB diseases. We reviewed 18F‐dopamine (18F‐DA) positron emission tomographic images and postmortem neurochemical data across several body organs of controls and patients with the LB synucleinopathies PD and pure autonomic failure (PAF) and the non‐LB synucleinopathy multiple system atrophy (MSA).Methods 18F‐DA–derived radioactivity in the heart, liver, spleen, pancreas, stomach, kidneys, thyroid, and submandibular glands were analyzed from 145 patients with LB synucleinopathies (112 PD, 33 PAF), 74 controls, and 85 MSA patients. In largely separate cohorts, postmortem tissue norepinephrine data were reviewed for heart, liver, spleen, pancreas, kidney, thyroid, submandibular gland, and sympathetic ganglion tissue from 38 PD, 2 PAF, and 5 MSA patients and 35 controls.ResultsInterventricular septal 18F‐DA–derived radioactivity was decreased in the LB synucleinopathy group compared to the control and MSA groups (P < 0.0001 each). The LB and non‐LB groups did not differ in liver, spleen, pancreas, stomach, or kidney 18F‐DA–derived radioactivity. The LB synucleinopathy group had markedly decreased apical myocardial norepinephrine, but normal tissue norepinephrine in other organs. The MSA group had normal tissue norepinephrine in all examined organs.InterpretationBy in vivo sympathetic neuroimaging and postmortem neurochemistry peripheral noradrenergic deficiency in LB synucleinopathies is cardioselective. MSA does not involve peripheral noradrenergic deficiency.

ANSH: Multimodal Neuroimaging Database Including MR Spectroscopic Data From Each Continent to Advance Alzheimer's Disease Research.

Alzheimer’s disease (AD) is a devastating neurodegenerative disorder affecting millions of people worldwide. The etiology of AD is not known, and intense research involving multimodal neuroimaging data (e.g., MRI, functional MRI, PET etc.) is extensively used to identify the causal molecular process for AD. In this context, various imaging-based databases accessible to researchers globally, are useful for an independent analysis. Apart from MRI-based brain imaging data, the neurochemical data using magnetic resonance spectroscopy (MRS) provide early molecular processes before the structural or functional changes are manifested. The existing imaging-based databases in AD lack the integration of MRS modality and, thus, limits the availability of neurochemical information to the AD research community. This perspective is an initiative to bring attention to the development of the neuroimaging database, “ANSH,” that includes brain glutathione (GSH), gamma aminobutyric acid (GABA) levels, and other neurochemicals along with MRI-based information for AD, mild cognitive impairment (MCI), and healthy subjects. ANSH is supported by a JAVA-based workflow environment and python providing a simple, dynamic, and distributed platform with data security. The platform consists of two-tiered architecture for data collection and management further supporting quality control, report generation for analyzed data, and data backup with a dedicated storage system. The ANSH database aims to present a single neuroimaging data platform incorporating diverse data types from healthy control and patient groups to provide better insights pertaining to disease progression. This data management platform provides flexible data sharing across users with continuous project monitoring. The development of ANSH platform will facilitate collaborative research and multi-site data sharing across the globe.

Flexible Multiplexed In2O3 Nanoribbon Aptamer-Field-Effect Transistors for Biosensing.

SummaryFlexible sensors are essential for advancing implantable and wearable bioelectronics toward monitoring chemical signals within and on the body. Developing biosensors for monitoring multiple neurotransmitters in real time represents a key in vivo application that will increase understanding of information encoded in brain neurochemical fluxes. Here, arrays of devices having multiple In2O3 nanoribbon field-effect transistors (FETs) were fabricated on 1.4-μm-thick polyethylene terephthalate (PET) substrates using shadow mask patterning techniques. Thin PET-FET devices withstood crumpling and bending such that stable transistor performance with high mobility was maintained over >100 bending cycles. Real-time detection of the small-molecule neurotransmitters serotonin and dopamine was achieved by immobilizing recently identified high-affinity nucleic-acid aptamers on individual In2O3 nanoribbon devices. Limits of detection were 10 fM for serotonin and dopamine with detection ranges spanning eight orders of magnitude. Simultaneous sensing of temperature, pH, serotonin, and dopamine enabled integration of physiological and neurochemical data from individual bioelectronic devices.

The effects of cycloprolylglycine and its analogues on brain monoaminergic systems in BALB/c mice

Effects of chronic cycloprolylglycine (CPG) and its analogues GZK-001 and GZK-002 treatment at the doses 1 and 2 mg/kg on levels of monoamines and their metabolites in BALB/c mice brain were determined by HPLC. Neurochemical data demonstrated that antidepressant-like effects of the peptides are mediated by an increase in NA and decrease in DA content in frontal cortex. Alterations in striatal monoamine metabolism were observed predominantly after CPG's analogues treatment: the concentration of DA was increased, although its rate of turnover was diminished. In hippocampus more active was CPG: the levels of NE, DA, 5-HT, and its metabolite 5-HIAA were decreased. GZK-001 (1 mg/kg) caused a decrease in the concentration of DA and 5-HIAA. The present results suggest that antidepressant-like effects of CPG and its analogues are associated with DA, NE, and 5-HT systems.

Current and Future Neuropharmacological Options for the Treatment of Essential Tremor.

Background Essential Tremor (ET) is likely the most frequent movement disorder. In this review, we have summarized the current pharmacological options for the treatment of this disorder and discussed several future options derived from drugs tested in experimental models of ET or from neuropathological data.Methods A literature search was performed on the pharmacology of essential tremors using PubMed Database from 1966 to July 31, 2019.Results To date, the beta-blocker propranolol and the antiepileptic drug primidone are the drugs that have shown higher efficacy in the treatment of ET. Other drugs tested in ET patients have shown different degrees of efficacy or have not been useful.Conclusion Injections of botulinum toxin A could be useful in the treatment of some patients with ET refractory to pharmacotherapy. According to recent neurochemical data, drugs acting on the extrasynaptic GABAA receptors, the glutamatergic system or LINGO-1 could be interesting therapeutic options in the future.

Olfacto-protective roles of Nigella sativa oil in Harmaline-induced essential tremor modelling

Background: Harmaline is a tremorgenic beta-carboline, reported to induce acute postural and kinetic tremor. Essential Tremor (ET) is an idiopathic slowly neurodegenerative tremor disorder which also compromises olfactory acuity. Nigella sativa (NS) is a therapeutic agent widely used in the treatment of various ailments. Objective: To determine the effect of NSon olfactory functions of mice treated with harmaline. Methods: Seventy-five BALB/c male mice weighing 20g-25g, were equally divided into five groups, namely CNTRL (received only Normal saline), NS (received NS oil1ml/kg), HML(received Harmaline 20mg/kg), HNS (received Harmaline and Nigella sativa concurrently), and NSH (received NSfollowed by Harmaline). Olfactory sensitivity and discrimination were assayed through buried food test. The olfactory bulb was assayed neurochemically for glutamate and dopamine, and histologically for neuronal architecture using haematoxylin and eosin stain. Differences in neurochemical and histological data, body weight, appetite, relative brain weight, sensitivity and discrimination indices were statistically analysed. Results: NS was significantly protective against the negative effects of Harmaline. It also effected quick olfactory discrimination, increased dopamine level, decrease in weight difference and increased food consumption in the animals. However, Harmaline increased relative brain weight and GPX levels. The concurrent administration aided in the reduction of neuronal density while neuronal average size reduced on pre-treatment with NS. Conclusion: Harmaline did not induce tremor in the animals, though it resulted in histological and neurochemical deficits. However, it resulted in olfactory insensitivity and indiscrimination, both of which were prevented and ameliorated by Nigella sativa oil.

Electrophysiological and Neurochemical Assessment of Selenium Alone or Combined with Carbamazepine in an Animal Model of Epilepsy

The present study aims to evaluate the efficacy of selenium (Se) alone or combined with carbamazepine (CBZ) against the adverse effects induced by the chemoconvulsant pentylenetetrazole (PTZ) in the cortex of adult male rats. Electrocorticogram (ECoG) and oxidative stress markers were implemented to evaluate the differences between treated and untreated animals. Animals were divided into five groups: control group that received i.p. saline injection, PTZ-treated group that received a single i.p. injection of PTZ (60mg/kg) for induction of seizures followed by a daily i.p. injection of saline, Se-treated group that received an i.p. injection of sodium selenite (0.3mg/kg/day) after PTZ administration, CBZ-treated group that received orally CBZ (80mg/kg/day) after PTZ administration, and combination (Se plus CBZ)-treated group that received an oral administration of CBZ (80mg/kg/day) followed by an i.p. injection of sodium selenite (0.3mg/kg/day) after PTZ administration. Quantitative analyses of the ECoG indices and the neurochemical parameters revealed that Se and CBZ have mitigated the adverse effects induced by PTZ. The main results were decrease in the number of epileptic spikes, restoring the normal distribution of slow and fast ECoG frequencies and attenuation of most of the oxidative stress markers. However, there was an increase in lipid perioxidation marker in combined treatment of CBZ and Se. The electrophysiological and neurochemical data proved the potential of these techniques in evaluating the treatment's efficiency and suggest that supplementation of Se with antiepileptic drugs (AEDs) may be beneficial in ameliorating most of the alterations induced in the brain as a result of seizure insults and could be recommended as an adjunct therapy with AEDs.

Neurobiological Risk Factors for the Development of Internet Addiction in Adolescents.

The sudden appearance and spread of Internet addiction in adolescent populations, in association with the rapid escalation of consumed Internet content and the broad availability of smartphones and tablets with Internet access, is posing a new challenge for classical addictology which requires urgent solutions. Like the majority of other psychopathological conditions, pathological Internet addiction depends upon a group of multifactor polygenic conditions. For each specific case, there is a unique combination of inherited characteristics (nervous tissue structure, secretion, degradation, and reception of neuromediators), and many are extra-environment factors (family-related, social, and ethnic-cultural). One of the main challenges in the development of the bio-psychosocial model of Internet addiction is to determine which genes and neuromediators are responsible for increased addiction susceptibility. This information will herald the start of a search for new therapeutic targets and the development of early prevention strategies, including the assessment of genetic risk levels. This review summarizes the literature and currently available knowledge related to neurobiological risk factors regarding Internet addiction in adolescents. Genetic, neurochemical and neuroimaging data are presented with links to actual pathogenetic hypotheses according to the bio-psychosocial model of IA forming.