Clinical and pharmacokinetic evaluation of risperidone for the management of autism spectrum disorder

TAAR1 and 5-HT1B receptor agonists attenuate autism-like irritability and aggression in rats prenatally exposed to valproic acid

Despite the rising prevalence of autism spectrum disorder (ASD), there remains a significant unmet need for pharmacotherapies addressing its core and associative symptoms. While some atypical antipsychotics have been approved for managing associated irritability and aggression, their use is constrained by substantial side effects. This study aimed firstly to develop behavioral measures to explore frustration, irritability and aggression phenotypes in the rat prenatal valproic acid (VPA) model of ASD. Additionally, we investigated the potential of two novel mechanisms, 5-HT1B and TAAR1 agonism, to alleviate these behaviors. Male offspring exposed to prenatal VPA were trained to achieve stable performance on a cued operant task, followed by pharmacological assessment in an operant frustration test, bottle brush test and resident intruder test. VPA exposed rats demonstrated behaviors indicative of frustration and irritability, as well as increased aggression compared to controls. The irritability-like behavior and aggression were further exacerbated in animals previously experiencing a frustrative event during the operant test. Single administration of the 5-HT1B agonist CP-94253 or TAAR1 agonist RO5263397 attenuated the frustration-like behavior compared to vehicle. Additionally, both agonists reduced irritability-like behavior under both normal and frustrative conditions. While CP-94253 reduced aggression in the resident intruder test under both conditions, RO5263397 only produced effects in rats that previously experienced a frustrative event. Our study describes previously uncharacterized phenotypes of frustration, irritability, and aggression in the rat prenatal VPA model of ASD. Administration of selective TAAR1 or 5-HT1B receptor agonists alleviated these deficits, warranting further exploration of both targets in ASD treatment.

Association of Parental Support with Reduced Stereotypy in Children with Autism Spectrum Disorder: A Cross-Sectional Study

Background and Objectives: To analyze the influence of parental presence and use of risperidone on social interaction and apathy among patients with Autism Spectrum Disorder (ASD). Materials and Methods: Cross-sectional study in a reference center for patients with ASD in a city in northeastern Brazil. The research was carried out using a sociodemographic questionnaire, the Dimensional Apathy Scale, and the Social Communication Questionnaire (SCQ) with the domains of social interaction, language, stereotypy, and communication. The referred questionnaire was answered by the parents or guardians of the children with ASD according to the DSM V criteria. Data were analyzed via independent t-test using the SPSS software version 20. Results: Interviews were conducted with 51 parents/guardians of autistic children with a mean age of 8.8 years (±2.95) and a predominance of males, 34 (66.7%). Of this total, 49 (96.1%) of the children attended school; 40 (78.4%) children were on medication, of which 38 (74.5%) were on risperidone. Those children on risperidone had a higher score on the SCQ scale (p = 0.049) and on the domain of stereotyped behaviors (p = 0.033), which indicated greater impairment. Another statistically relevant variable was the presence of married parents, whereby children who did not have the presence of married parents had a higher average of stereotyped behaviors compared to those who had married parents. Conclusions: The results showed differences in the means of social interactions for children on risperidone, especially regarding stereotyped behaviors. However, it is not possible to state whether this difference was due to the use of risperidone or whether they used risperidone precisely because of these behaviors. Also important was that children who had the presence of married parents showed fewer stereotyped behaviors. There was no difference in apathetic behavior between children.

Practitioner's review: medication for children and adolescents with autism spectrum disorder (ASD) and comorbid conditions

Alleviating the multiple problems of children with autism spectrum disorder (ASD) and its comorbid conditions presents major challenges for the affected children, parents, and therapists. Because of a complex psychopathology, structured therapy and parent training are not always sufficient, especially for those patients with intellectual disability (ID) and multiple comorbidities. Moreover, structured therapy is not available for a large number of patients, and pharmacological support is often needed, especially in those children with additional attention deficit/hyperactivity and oppositional defiant, conduct, and sleep disorders.

The Potential of Carnosine in Brain-Related Disorders: A Comprehensive Review of Current Evidence

Neurological, neurodegenerative, and psychiatric disorders represent a serious burden because of their increasing prevalence, risk of disability, and the lack of effective causal/disease-modifying treatments. There is a growing body of evidence indicating potentially favourable effects of carnosine, which is an over-the-counter food supplement, in peripheral tissues. Although most studies to date have focused on the role of carnosine in metabolic and cardiovascular disorders, the physiological presence of this di-peptide and its analogues in the brain together with their ability to cross the blood-brain barrier as well as evidence from in vitro, animal, and human studies suggest carnosine as a promising therapeutic target in brain disorders. In this review, we aim to provide a comprehensive overview of the role of carnosine in neurological, neurodevelopmental, neurodegenerative, and psychiatric disorders, summarizing current evidence from cell, animal, and human cross-sectional, longitudinal studies, and randomized controlled trials.

Risperidone-Induced Renal Damage and Metabolic Side Effects: The Protective Effect of Resveratrol

Objective

The aim of the study was to investigate the possible protective qualities of resveratrol (RSV) against the side effects of risperidone (RIS) in an experimental model in rat kidneys with histologic and biochemical assessments.

Materials and Methods

Experimental procedures were performed on 35 female Sprague Dawley rats. Rats were randomly divided into five groups: control, untreated rats (n = 7) were in group 1; group 2 was given 2 mg/kg/day RIS (n = 7); group 3 was treated with 2 mg/kg/day RIS and 20 mg/kg/day RSV (n = 7); group 4 was treated with 2 mg/kg/day RIS and 40 mg/kg/day RSV (n = 7); and group 5 was treated with 2 mg/kg/day RIS and 80 mg/kg/day RSV (n = 7). All treatments were administered for two weeks by gavage. On treatment day 15, kidney tissues were removed for analysis.

Results

The results showed that RSV treatment reduced weight gain induced by RIS. In addition, RSV increased the total antioxidant status (TAS) and decreased serum creatinine (Cr), blood urea nitrogen (BUN), oxidative stress index (OSI), and total oxidant status (TOS) levels significantly (p < 0.05).

Conclusion

This study revealed that treatment with RSV might protect kidney tissues against the side effects of RIS. RSV could be an effective course of therapy to enhance therapeutic efficacy.

Comparative Distribution of Relaxin-3 Inputs and Calcium-Binding Protein-Positive Neurons in Rat Amygdala

The neural circuits involved in mediating complex behaviors are being rapidly elucidated using various newly developed and powerful anatomical and molecular techniques, providing insights into the neural basis for anxiety disorders, depression, addiction, and dysfunctional social behaviors. Many of these behaviors and associated physiological processes involve the activation of the amygdala in conjunction with cortical and hippocampal circuits. Ascending subcortical projections provide modulatory inputs to the extended amygdala and its related nodes (or "hubs") within these key circuits. One such input arises from the nucleus incertus (NI) in the tegmentum, which sends amino acid- and peptide-containing projections throughout the forebrain. Notably, a distinct population of GABAergic NI neurons expresses the highly-conserved neuropeptide, relaxin-3, and relaxin-3 signaling has been implicated in the modulation of reward/motivation and anxiety- and depressive-like behaviors in rodents via actions within the extended amygdala. Thus, a detailed description of the relaxin-3 innervation of the extended amygdala would provide an anatomical framework for an improved understanding of NI and relaxin-3 modulation of these and other specific amygdala-related functions. Therefore, in this study, we examined the distribution of NI projections and relaxin-3-positive elements (axons/fibers/terminals) within the amygdala, relative to the distribution of neurons expressing the calcium-binding proteins, parvalbumin (PV), calretinin (CR) and/or calbindin. Anterograde tracer injections into the NI revealed a topographic distribution of NI efferents within the amygdala that was near identical to the distribution of relaxin-3-immunoreactive fibers. Highest densities of anterogradely-labeled elements and relaxin-3-immunoreactive fibers were observed in the medial nucleus of the amygdala, medial divisions of the bed nucleus of the stria terminalis (BST) and in the endopiriform nucleus. In contrast, sparse anterogradely-labeled and relaxin-3-immunoreactive fibers were observed in other amygdala nuclei, including the lateral, central and basal nuclei, while the nucleus accumbens lacked any innervation. Using synaptophysin as a synaptic marker, we identified relaxin-3 positive synaptic terminals in the medial amygdala, BST and endopiriform nucleus of amygdala. Our findings demonstrate the existence of topographic NI and relaxin-3-containing projections to specific nuclei of the extended amygdala, consistent with a likely role for this putative integrative arousal system in the regulation of amygdala-dependent social and emotional behaviors.

Sleep in Autism Spectrum Disorders

Autism spectrum disorders (ASD) are common neurodevelopmental conditions, affecting 1 in 68 children. Sleep disturbance, particularly insomnia, is very common in children diagnosed with ASD, with evidence supporting overlapping neurobiological and genetic underpinnings. Disturbed sleep exacerbates core and related ASD symptoms and has a substantial negative impact on the entire family. Treatment of sleep disturbance holds promise for ameliorating many of the challenging behavioral symptoms that children with ASD and their families face. Behavioral and pharmacological studies indicate promising approaches to treating sleep disturbances in this population. Awareness of treatment options is particularly important as parents and clinicians may believe that sleep disturbance is part of autism and refractory to therapy. In addition, autism symptoms refractory to treatment with conventional psychiatric medications may improve when sleep is addressed. Additional evidence-based studies are needed, including those that address the underlying biology of this condition.