Exploring the role of ghrelin and des-acyl ghrelin in chemotherapy-induced nausea and vomiting.

Ghrelin and its mimetics have been shown to reduce cisplatin-induced emesis in preclinical studies using ferrets and shrews. This study investigated the effectiveness of ghrelin and des-acyl ghrelin (DAG) in antagonizing cisplatin-induced emesis and physiological changes indicative of nausea in Suncus murinus. Animals implanted with radiotelemetry devices were administered ghrelin (0.2, 1.0, and 5.0 µg/day), DAG (0.2, 1.0, and 5.0 µg/day), or saline (14 µL/day) intracerebroventricularly 4 days before and 3 days after treatment with cisplatin (30 mg/kg). At the end, the anti-apoptotic potentials of ghrelin and DAG were assessed by measuring Bax expression and cytochrome C activity. Neurotransmitter changes in the brain were evaluated using liquid chromatography-mass spectrometry analysis. Ghrelin and DAG reduced cisplatin-induced emesis in the delayed (24-72 h) but not the acute phase (0-24 h) of emesis. Ghrelin also partially reversed the inhibitory effects of cisplatin on food intake without affecting gastrointestinal myoelectrical activity or causing hypothermia; however, ghrelin or DAG did not prevent these effects. Ghrelin and DAG could attenuate the cisplatin-induced upregulation of Bax and cytochrome C in the ileum. Cisplatin dysregulated neurotransmitter levels in the frontal cortex, amygdala, thalamus, hypothalamus, and brainstem, and this was partially restored by low doses of ghrelin and DAG. Our findings suggest that ghrelin and DAG exhibit protective effects against cisplatin-induced delayed emesis. The underlying antiemetic mechanism may involve GHSR and/or unspecified pathways that modulate the neurotransmitters involved in emesis control in the brain and an action to attenuate apoptosis in the gastrointestinal tract.

Puerarin Attenuates Cycloheximide-Induced Oxidative Damage and Memory-Consolidation Impairment in Rats.

BACKGROUND: Cycloheximide (CXM), an antifungal antibiotic, causes impaired memory consolidation as a side effect partially by disturbing the activities of the central catecholaminergic and cholinergic system. Some reports indicated that puerarin prevented memory impairment in various models in rodents. However, the protective effects of puerarin on the side effects of cycloheximide for memory consolidation impairment have not yet been investigated. METHODS: The protective effects of puerarin on CXM-induced memory-consolidation impairment, and memory impairment produced by central administration of AF64A neurotoxin, were investigated using a passive avoidance task in rats. A combination of transmitter receptor agonists and antagonists was used to explore the effects of puerarin on nervous system function. The activity of antioxidant defense systems and neurotransmitter systems in the prefrontal cortex and hippocampus were assayed. RESULTS: Systemic (25 and 50 mg/kg, i.p.) or central (5 and 10 µg/brain, i.c.v.) administration of puerarin attenuated CXM-induced memory-consolidation impairment produced by 1.5 mg/kg CXM (s.c.) in rats. The improvements produced by 50 mg/kg puerarin were blocked by cholinergic antagonists, a 5-HT2 receptor agonist, and an adrenergic receptor antagonist. Puerarin (only at 50 mg/kg, i.p.) reversed the CXM-induced alterations of the levels of norepinephrine in the prefrontal cortex and the levels of monoamines in the hippocampus. Puerarin also increased antioxidant-defense-system activities in the prefrontal cortex and hippocampus, which had been decreased by CXM. CONCLUSIONS: We suggested that the attenuating effects of puerarin on CXM-induced memory-consolidation impairment may be due to decrease oxidative damage and the normalition of the neurotransmitter function in the prefrontal cortex and hippocampus.

Myenteric Plexus Immune Cell Infiltrations and Neurotransmitter Expression in Crohn's Disease and Ulcerative Colitis.

BACKGROUND AND AIMS: Pain is a cardinal symptom in inflammatory bowel disease [IBD]. An important structure in the transduction of pain signalling is the myenteric plexus [MP]. Nevertheless, IBD-associated infiltration of the MP by immune cells lacks in-depth characterisation. Herein, we decipher intra- and periganglionic immune cell infiltrations in Crohn´s disease [CD] and ulcerative colitis [UC] and provide a comparison with murine models of colitis. METHODS: Full wall specimens of surgical colon resections served to examine immune cell populations by either conventional immuno-histochemistry or immunofluorescence followed by either bright field or confocal microscopy. Results were compared with equivalent examinations in various murine models of intestinal inflammation. RESULTS: Whereas the MP morphology was not significantly altered in IBD, we identified intraganglionic IBD-specific B cell- and monocyte-dominant cell infiltrations in CD. In contrast, UC-MPs were infiltrated by CD8+ T cells and revealed a higher extent of ganglionic cell apoptosis. With regard to the murine models of intestinal inflammation, the chronic dextran sulphate sodium [DSS]-induced colitis model reflected CD [and to a lesser extent UC] best, as it also showed increased monocytic infiltration as well as a modest B cell and CD8+ T cell infiltration. CONCLUSIONS: In CD, MPs were infiltrated by B cells and monocytes. In UC, mostly CD8+ cytotoxic T cells were found. The chronic DSS-induced colitis in the mouse model reflected best the MP-immune cell infiltrations representative for IBD.

Minocycline and Pyrrolidine Dithiocarbamate Attenuate Hypertension via Suppressing Activation of Microglia in the Hypothalamic Paraventricular Nucleus.

Proinflammatory cytokines, reactive oxygen species and imbalance of neurotransmitters are involved in the pathophysiology of angiotensin II-induced hypertension. The hypothalamic paraventricular nucleus (PVN) plays a vital role in hypertension. Evidences show that microglia are activated and release proinflammatory cytokines in angiocardiopathy. We hypothesized that angiotensin II induces PVN microglial activation, and the activated PVN microglia release proinflammatory cytokines and cause oxidative stress through nuclear factor-kappa B (NF-κB) pathway, which contributes to sympathetic overactivity and hypertension. Male Sprague-Dawley rats (weight 275-300 g) were infused with angiotensin II to induce hypertension. Then, rats were treated with bilateral PVN infusion of microglial activation inhibitor minocycline, NF-κB activation inhibitor pyrrolidine dithiocarbamate or vehicle for 4 weeks. When compared to control groups, angiotensin II-induced hypertensive rats had higher mean arterial pressure, PVN proinflammatory cytokines, and imbalance of neurotransmitters, accompanied with PVN activated microglia. These rats also had more PVN gp91phox (source of reactive oxygen species production), and NF-κB p65. Bilateral PVN infusion of minocycline or pyrrolidine dithiocarbamate partly or completely ameliorated these changes. This study indicates that angiotensin II-induced hypertensive rats have more activated microglia in PVN, and activated PVN microglia release proinflammatory cytokines and result in oxidative stress, which contributes to sympathoexcitation and hypertensive response. Suppression of activated PVN microglia by minocycline or pyrrolidine dithiocarbamate attenuates inflammation and oxidative stress, and improves angiotensin II-induced hypertension, which indicates that activated microglia promote hypertension through activated NF-κB. The findings may offer hypertension new strategies.

Erigeron annuus flower absolute prolongs botulinum neurotoxin A-induced muscle paralysis and inhibits neurotransmitter release-linked responses.

This study aimed to determine the effects of Erigeron annuus (L.) Pers. (EAP) flower absolute (EAPFAb) on neurotransmitter release-blocking events and muscle paralysis induced by botulinum neurotoxin type A (BoNT/A). For this study, EAPFAb was extracted from EAP flowers by solvent extraction and its composition was determined by GC/MS. Neurotransmitter release and SNARE protein expression were examined in PC12 cells by ELISA and immunoblotting. Rat hind limbs were tested for muscle paralysis. EAPFAb contained 23 components and prolonged the duration of BoNT/A-induced rat hind limb muscle paralysis. EAPFAb reduced neurotransmitter release induced by elevated extracellular potassium levels and attenuated SNARE protein expression in PC12 cells. These findings demonstrate that EAPFAb prolongs BoNT/A-induced muscle paralysis action, probably by inhibiting releases of neurotransmitters that are regulated by SNARE proteins in neural cells. EAPFAb may be a promising material for prolonging BoNT/A action.

Neuroscientific therapies for atrial fibrillation.

The cardiac autonomic nervous system (ANS) plays an integral role in normal cardiac physiology as well as in disease states that cause cardiac arrhythmias. The cardiac ANS, comprised of a complex neural hierarchy in a nested series of interacting feedback loops, regulates atrial electrophysiology and is itself susceptible to remodelling by atrial rhythm. In light of the challenges of treating atrial fibrillation (AF) with conventional pharmacologic and myoablative techniques, increasingly interest has begun to focus on targeting the cardiac neuraxis for AF. Strong evidence from animal models and clinical patients demonstrates that parasympathetic and sympathetic activity within this neuraxis may trigger AF, and the ANS may either induce atrial remodelling or undergo remodelling itself to serve as a substrate for AF. Multiple nexus points within the cardiac neuraxis are therapeutic targets, and neuroablative and neuromodulatory therapies for AF include ganglionated plexus ablation, epicardial botulinum toxin injection, vagal nerve (tragus) stimulation, renal denervation, stellate ganglion block/resection, baroreceptor activation therapy, and spinal cord stimulation. Pre-clinical and clinical studies on these modalities have had promising results and are reviewed here.

The action of aripiprazole and brexpiprazole at the receptor level in singultus.

The hiccup (Latin singultus) is an involuntary periodic contraction of the diaphragm followed by glottic closure, which can be a rare side effect of aripiprazole. In contrast to the structurally closely related aripiprazole, brexpiprazole was not associated with this particular adverse drug reaction. Having two very similar drugs that differ in their ability to induce hiccups represents a unique opportunity to gain insight into the receptors involved in the pathophysiology of the symptom and differences in clinical effects between aripiprazole and brexpiprazole. The overlap between maneuvers used to terminate paroxysmal supraventricular tachycardia and those employed to terminate bouts of hiccups suggests that activation of efferent vagal fibers can be therapeutic in both instances. Recent work seems to support a pivotal role for serotonin receptors in such vagal activation. It is unlikely that a unique receptor-drug interaction could explain the different effects of the examined drugs on hiccup. The different effect is most likely the consequence of several smaller effects at more than one receptor. Brexpiprazole is a highly affine (potent) α2C antagonist and, therefore, also an indirect 5-HT1A agonist. In contrast, aripiprazole is a partial 5-HT1A agonist (weak antagonist) and an HT3 antagonist. Activation of 5-HT1A receptors enhances vagal activity while HT3 blockade reduces it. Vagus nerve activation is therapeutic for hiccups. A definitive answer continues to be elusive.

Distribution, Ecology, Chemistry and Toxicology of Plant Stinging Hairs.

Plant stinging hairs have fascinated humans for time immemorial. True stinging hairs are highly specialized plant structures that are able to inject a physiologically active liquid into the skin and can be differentiated from irritant hairs (causing mechanical damage only). Stinging hairs can be classified into two basic types: Urtica-type stinging hairs with the classical "hypodermic syringe" mechanism expelling only liquid, and Tragia-type stinging hairs expelling a liquid together with a sharp crystal. In total, there are some 650 plant species with stinging hairs across five remotely related plant families (i.e., belonging to different plant orders). The family Urticaceae (order Rosales) includes a total of ca. 150 stinging representatives, amongst them the well-known stinging nettles (genus Urtica). There are also some 200 stinging species in Loasaceae (order Cornales), ca. 250 stinging species in Euphorbiaceae (order Malphigiales), a handful of species in Namaceae (order Boraginales), and one in Caricaceae (order Brassicales). Stinging hairs are commonly found on most aerial parts of the plants, especially the stem and leaves, but sometimes also on flowers and fruits. The ecological role of stinging hairs in plants seems to be essentially defense against mammalian herbivores, while they appear to be essentially inefficient against invertebrate pests. Stinging plants are therefore frequent pasture weeds across different taxa and geographical zones. Stinging hairs are usually combined with additional chemical and/or mechanical defenses in plants and are not a standalone mechanism. The physiological effects of stinging hairs on humans vary widely between stinging plants and range from a slight itch, skin rash (urticaria), and oedema to sharp pain and even serious neurological disorders such as neuropathy. Numerous studies have attempted to elucidate the chemical basis of the physiological effects. Since the middle of the 20th century, neurotransmitters (acetylcholine, histamine, serotonin) have been repeatedly detected in stinging hairs of Urticaceae, but recent analyses of Loasaceae stinging hair fluids revealed high variability in their composition and content of neurotransmitters. These substances can explain some of the physiological effects of stinging hairs, but fail to completely explain neuropathic effects, pointing to some yet unidentified neurotoxin. Inorganic ions (e.g., potassium) are detected in stinging hairs and could have synergistic effects. Very recently, ultrastable miniproteins dubbed "gympietides" have been reported from two species of Dendrocnide, arguably the most violently stinging plant. Gympietides are shown to be highly neurotoxic, providing a convincing explanation for Dendrocnide toxicity. For the roughly 648 remaining stinging plant species, similarly convincing data on toxicity are still lacking.

Broad Efficacy of Cariprazine on Depressive Symptoms in Bipolar Disorder and the Clinical Implications.

INTRODUCTION: Bipolar disorder is a complex mood disorder characterized by a chronic and subtle course of fluctuating manic/hypomanic and depressive symptoms. Cariprazine, a dopamine D3-preferring D3/D2 receptor partial agonist with serotonin 5-HT1A receptor partial agonist and serotonin 5-HT2A antagonist properties, is approved to treat manic and depressive episodes of bipolar disorder. Post hoc analyses evaluated efficacy across symptoms in bipolar depression. METHODS: Pooled data were analyzed from 3 phase 2 or 3, randomized, double-blind, placebo-controlled studies of adults with bipolar disorder and a major depressive episode. Mean change from baseline to week 6 in Montgomery-Asberg Depression Rating Scale (MADRS) total score and individual item scores were analyzed in individual dose groups (1.5 mg/d, 3 mg/d) and overall cariprazine (1.5-3 mg/d). Pooled safety was evaluated via adverse events. RESULTS: A significantly greater difference in mean change from baseline in MADRS total score was seen for each cariprazine dose group versus placebo (least squares mean difference vs placebo: 1.5-3 mg/d = -2.6, 1.5 mg/d = -2.8, 3 mg/d = -2.4) (P < .001 all). Significant differences versus placebo were seen on all individual MADRS items except inner tension for the overall cariprazine group (P < .05). Cariprazine was generally well tolerated. CONCLUSIONS: Cariprazine demonstrated broad efficacy across symptoms of depression in bipolar disorder. In previous post hoc analyses, cariprazine also demonstrated broad efficacy across manic symptoms, suggesting that it is effective across the wide range of symptoms on the bipolar spectrum. A 1.5-mg/d starting dose and slow titration resulted in lower rates of some adverse events in the bipolar depression studies versus the mania studies. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT01396447, NCT02670538, NCT02670551.

Efficacy and safety of brexpiprazole in patients with schizophrenia presenting with severe symptoms: Post-hoc analysis of short- and long-term studies.

BACKGROUND: The treatment of patients with severe schizophrenia symptoms can be complicated and expensive. AIMS: The purpose of this study was to evaluate the short- and long-term effects of brexpiprazole in patients with schizophrenia presenting with severe symptoms. METHODS: Data were pooled from three six-week, randomized, double-blind, placebo-controlled studies and two 52-week, open-label extension studies. In the short-term studies, 1405 patients received placebo or brexpiprazole 2-4 mg/day; 412 brexpiprazole-treated patients rolled over into the long-term studies and received brexpiprazole 1-4 mg/day. More severe symptoms were defined as a Positive and Negative Syndrome Scale Total score >95 (median score at baseline). Outcomes included change in Positive and Negative Syndrome Scale Total and Personal and Social Performance scale scores. RESULTS: Brexpiprazole improved Positive and Negative Syndrome Scale Total score over 6 weeks among more severely ill patients, with a least squares mean difference versus placebo of -6.76 (95% confidence limits: -9.80, -3.72; p<0.0001; Cohen's d: 0.43). Brexpiprazole also improved Personal and Social Performance scale score over 6 weeks in more severely ill patients (least squares mean difference: 4.38; limits: 2.14, 6.62; p=0.0001; Cohen's d: 0.38). Improvement of functioning was greatest in the 'Self-care' domain, followed by 'Personal and social relationships'. Among less severely ill patients, brexpiprazole was superior to placebo on Positive and Negative Syndrome Scale Total and Personal and Social Performance scale at Week 6. Improvements were maintained over 58 weeks. No new safety or tolerability concerns were observed. CONCLUSIONS: Brexpiprazole is an efficacious and well-tolerated treatment for schizophrenia in patients with more severe, and less severe, symptoms.

Visual Hallucinations and the Role of Medications in Parkinson's Disease: Triggers, Pathophysiology, and Management.

Visual hallucinations, which are part of the syndrome of Parkinson's disease (PD) psychosis, affect patients' quality of life and increase the likelihood of residential aged-care placement. The association between visual hallucinations and dopaminergic and other medications that are necessary for the symptomatic management of motor and other symptoms of PD is a common clinical dilemma. While dopaminergic medications have long been associated with PD psychosis, a clear causal link has not been established, and other neurotransmitter systems, particularly noradrenaline, serotonin, and acetylcholine, are implicated and important. A diverse range of demographic and disease-related risk factors, some being modifiable, highlight the complexity of potential underlying pathophysiological processes but also broaden practical options for prevention and treatment that can be multifaceted and individualized. The investigators reviewed the clinical features and epidemiology of visual hallucinations and PD, explored the pathological evidence for dysfunction of multiple neurotransmitter systems that may be relevant to these phenomena, and addressed the potential of medications commonly used in PD to either trigger or treat these symptoms.

FG 7142: is this validated tool to study anxiety now forgotten?

We describe the first human experience with FG 7142, a drug which in a phase I study has caused severe anxiety attacks and which therefore could be a validated tool for further experimental studies of anxiety.

Pharmacotherapy for the Pseudobulbar Affect in Individuals Who Have Sustained a Traumatic Brain Injury: a Systematic Review.

Pseudobulbar affect is a debilitating condition that significantly reduces quality of life for many individuals following traumatic brain injury (TBI). It is characterized by embarrassing and often uncontrollable episodes of crying or laughter. The aim of this systematic review was to evaluate the effectiveness of pharmacotherapy as compared to all other comparators for the management of pseudobulbar affect in adults who have sustained TBI. Six databases were searched, with additional hand searching of journals, clinical trials registries and international drug regulators to identify published and unpublished studies in English up to June 2018. Studies were eligible for this review if they included adults who had sustained a medically confirmed TBI and presented with pseudobulbar affect. All pharmacotherapy and comparator interventions were considered for inclusion, and study design was not limited to randomised controlled trials. Evidence quality was assessed using Joanna Briggs Institute Critical Appraisal Instruments. Two quasi-experimental studies examining the effectiveness of dextrometamorphan/quinidine (DM/Q) were identified. These studies reported that DM/Q was effective in reducing symptoms of pseudobulbar affect and had a positive safety profile, over follow-up periods of 3 months (n = 87) and 12 months (n = 23). However, both studies were limited by lack of a control group and a high dropout rate. The findings of twelve case reports examining the effectiveness of DM/Q (n = 6) and anti-depressants (n = 6) are also discussed. Further research is required to determine which pharmacological interventions provide the best outcomes for individuals with pseudobulbar affect following TBI, with consideration given to side effect profiles and financial costs.

Beyond stimulants: a systematic review of randomised controlled trials assessing novel compounds for ADHD.

Introduction: Despite stimulants being highly efficacious in short-term randomized controlled trials (RCTs), not all patients respond or can successfully tolerate them. A number of novel non-stimulant options are currently in the pipeline for the treatment of attention-deficit/hyperactivity disorder (ADHD). Areas covered: The authors conducted a systematic review of RCTs registered in ClinicalTrials.gov in the past 5 years (January 2014 and February 2019), supplemented by searches in PubMed, Web of Science, and drug manufacturer websites to find recent RCTs on novel non-stimulant ADHD medications. Expert opinion: The authors found 28 pertinent RCTs of compounds acting on a variety of biological targets, including Dasotraline, Viloxazine (SPN-812), Centanafadine SR (CTN SR), OPC-64005, Fasoracetam (NFC-1, AEVI-001), Metadoxine (MDX), Vortioxetine, Tipepidine Hibenzate, Oxytocin, Sativex (delta-9-tetrahydrocannabinol (THC) plus cannabidiol), Mazindol, and Molindone hydrochloride (SPN-810). Given the high effect size found in RCTs of stimulants in terms of efficacy on ADHD core symptoms, it is unlikely that these novel agents will show better efficacy than stimulants, at the group level. However, they may offer comparable or better tolerability. Additionally, agents acting on etiopathophysiological targets disrupted in specific subgroups of patients with ADHD will move forward the pharmacotherapy of ADHD from a 'one size fits all' to a 'precision medicine' approach.

Receptor Ligands as Helping Hands to L-DOPA in the Treatment of Parkinson's Disease.

Levodopa (LD) is the most effective drug in the treatment of Parkinson's disease (PD). However, although it represents the "gold standard" of PD therapy, LD can cause side effects, including gastrointestinal and cardiovascular symptoms as well as transient elevated liver enzyme levels. Moreover, LD therapy leads to LD-induced dyskinesia (LID), a disabling motor complication that represents a major challenge for the clinical neurologist. Due to the many limitations associated with LD therapeutic use, other dopaminergic and non-dopaminergic drugs are being developed to optimize the treatment response. This review focuses on recent investigations about non-dopaminergic central nervous system (CNS) receptor ligands that have been identified to have therapeutic potential for the treatment of motor and non-motor symptoms of PD. In a different way, such agents may contribute to extending LD response and/or ameliorate LD-induced side effects.

Topiramate Pharmacotherapy for Alcohol Use Disorder and Other Addictions: A Narrative Review.

: Topiramate is a non-benzodiazepine anticonvulsant medication with multi-faceted pharmacologic action. It has emerged as an efficacious pharmacotherapeutic option for the treatment of addiction, especially alcohol use disorder (AUD). We present a broad narrative review of the putative mechanism of action and clinical utility of topiramate with regard to AUD and other substance use disorders. Collective evidence suggests topiramate is an effective treatment option in AUD, with notable efficacy in reducing harmful drinking patterns in AUD. Though not currently approved by the United States Food and Drug Administration for the indication of AUD, topiramate should be considered as a pharmacological treatment option with high utility among AUD patients. Early pharmacogenetic studies raise the intriguing possibility of identifying patients likely to respond to topiramate using genetic testing, and initial studies show that topiramate may also be useful in treating cocaine use disorder, smoking cessation and behavioral addictions. However, further research is needed in all these areas.

The past and future of novel, non-dopamine-2 receptor therapeutics for schizophrenia: A critical and comprehensive review.

Since the discovery of chlorpromazine in the 1950's, antipsychotic drugs have been the cornerstone of treatment of schizophrenia, and all attenuate dopamine transmission at the dopamine-2 receptor. Drug development for schizophrenia since that time has led to improvements in side effects and tolerability, and limited improvements in efficacy, with the exception of clozapine. However, the reasons for clozapine's greater efficacy remain unclear, despite the great efforts and resources invested therewith. We performed a comprehensive review of the literature to determine the fate of previously tested, non-dopamine-2 receptor experimental treatments. Overall we included 250 studies in the review from the period 1970 to 2017 including treatments with glutamatergic, serotonergic, cholinergic, neuropeptidergic, hormone-based, dopaminergic, metabolic, vitamin/naturopathic, histaminergic, infection/inflammation-based, and miscellaneous mechanisms. Despite there being several promising targets, such as allosteric modulation of the NMDA and α7 nicotinic receptors, we cannot confidently state that any of the mechanistically novel experimental treatments covered in this review are definitely effective for the treatment of schizophrenia and ready for clinical use. We discuss potential reasons for the relative lack of progress in developing non-dopamine-2 receptor treatments for schizophrenia and provide recommendations for future efforts pursuing novel drug development for schizophrenia.

Activation of trace amine-associated receptor 1 attenuates schedule-induced polydipsia in rats.

Trace Amine Associated Receptor 1 (TAAR1) is a novel pharmacological target. TAAR1 are well-documented to play a modulatory role in the dopaminergic system. In spite of a growing number of studies of TAAR1 effects, little is still known about the behavioral pharmacology of TAAR1 ligands, including effects of repeated TAAR1 agonist administration. The present study appears to be the first that estimated the action of TAAR1 agonists on schedule-induced polydipsia, a type of adjunctive behavior, which is considered to be useful for evaluating certain aspects of obsessive-compulsive and related disorders (OCD) and schizophrenia. Our results have demonstrated that the wide range of RO5263397, the highly selective partial TAAR1 agonist, doses (1-10 mg/kg) attenuated the polydipsia induced by two different schedules of food delivery in rats. The effect remained unchanged for the 7 days of repeated treatment. However, the highest tested doses of RO5263397 (6 and 10 mg/kg) decreased the vertical locomotor activity of the animals and the volume of water intake of thirsty rats following the acute treatment. Also, though, the repeated RO5263397 administration is exhibited to diminish the volume of consumed water and weight of rats without SIP, on the other hand, the tolerance was observed to these drug effects. In general, the RO5263397 decreases specifically the adjunctive drinking and this effect is maintained with repeated drug administration without the development of tolerance. The interpretation of these results as an evidence for the RO5263397 anticompulsive-like action, however, should be taken with caution because the drug also influenced the drinking behavior and only weakly affected the other parameters of SIP used to reveal the potential anticompulsive-like effects of drugs.