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Innovations in Clinical Neuroscience 2024Stimulants are the first-line pharmacological treatment for attention deficit hyperactivity disorder (ADHD). We present the unique case of a patient who developed a...
Stimulants are the first-line pharmacological treatment for attention deficit hyperactivity disorder (ADHD). We present the unique case of a patient who developed a chewing compulsion when taking mixed amphetamine salts (MAS). A 32-year-old female patient with a past medical history of gastroesophageal reflux disease (GERD), gastroparesis, and migraines was seen for initial psychiatric assessment due to concerns for irritability. She was diagnosed with post-traumatic stress disorder (PTSD); generalized anxiety disorder; ADHD, inattentive type; and unspecified bipolar disorder. Lamotrigine was started and titrated to 25mg twice per day, with improved mood stability. MAS immediate-release (IR) was started at 2.5mg and titrated to 5mg daily for ADHD. She then experienced an uncontrollable urge to chew, finding relief when chewing on a child's teething necklace, which provided satisfaction and a reduction in anxiety. She denied jaw tightness or teeth grinding. The dose of MAS IR was reduced to 2.5mg daily with improvement in symptoms and later increased again to 5mg daily, which she was then able to tolerate. Stereotyped biting behaviors have been observed in rats with the use of amphetamines, and the onset of compulsive behavior has emerged in children with the use of dextroamphetamine. However, this is the first known case of compulsive chewing or biting movements reported in humans with MAS use. This case highlights the need to assess patients for adverse events, such as compulsive biting and chewing movements or other oral facial stereotypies, after commencement of stimulants, including MAS.
PubMed: 38938532
DOI: No ID Found -
Current Biology : CB Jun 2024Escape behavior is a set of locomotor actions that move an animal away from threat. While these actions can be stereotyped, it is advantageous for survival that they are...
Escape behavior is a set of locomotor actions that move an animal away from threat. While these actions can be stereotyped, it is advantageous for survival that they are flexible. For example, escape probability depends on predation risk and competing motivations, and flight to safety requires continuous adjustments of trajectory and must terminate at the appropriate place and time. This degree of flexibility suggests that modulatory components, like inhibitory networks, act on the neural circuits controlling instinctive escape. In mice, the decision to escape from imminent threats is implemented by a feedforward circuit in the midbrain, where excitatory vesicular glutamate transporter 2-positive (VGluT2) neurons in the dorsal periaqueductal gray (dPAG) compute escape initiation and escape vigor. Here we tested the hypothesis that local GABAergic neurons within the dPAG control escape behavior by setting the excitability of the dPAG escape network. Using in vitro patch-clamp and in vivo neural activity recordings, we found that vesicular GABA transporter-positive (VGAT) dPAG neurons fire action potentials tonically in the absence of synaptic inputs and are a major source of inhibition to VGluT2 dPAG neurons. Activity in VGAT dPAG cells transiently decreases at escape onset and increases during escape, peaking at escape termination. Optogenetically increasing or decreasing VGAT dPAG activity changes the probability of escape when the stimulation is delivered at threat onset and the duration of escape when delivered after escape initiation. We conclude that the activity of tonically firing VGAT dPAG neurons sets a threshold for escape initiation and controls the execution of the flight action.
PubMed: 38936364
DOI: 10.1016/j.cub.2024.05.068 -
Heliyon Jun 2024Autism spectrum disorder (ASD) is a behaviorally defined complex neurodevelopmental syndrome characterized by persistent social communication and interaction deficit.... (Review)
Review
Autism spectrum disorder (ASD) is a behaviorally defined complex neurodevelopmental syndrome characterized by persistent social communication and interaction deficit. Transcranial magnetic stimulation (TMS) is a promising and emerging tool for the intervention of ASD by reducing both core and associate symptoms. Several reviews have been published regarding TMS-based ASD treatment, however, a systematic review on study characteristics, specific stimulating parameters, localization techniques, stimulated targets, behavioral outcomes, and neuroimage biomarker changes is lagged behind since 2018. Here, we performed a systematic search on literatures published after 2018 in PubMed, Web of Science, and Science Direct. After screening, the final systematic review included 17 articles, composing seven randomized controlled trial studies and ten open-label studies. Two studies are double-blind, while the other studies have a moderate to high risk of bias attributing to inadequate subject- and evaluator-blinding to treatment allocation. Five studies utilize theta-burst stimulation mode, and the others apply repetitive TMS with low frequency (five studies), high frequency (six studies), and combined low and high frequency stimulation (one study). Most researchers prioritize the bilateral dorsolateral prefrontal lobe as stimulation target, while parietal lobule, inferior parietal lobule, and posterior superior temporal sulci have also emerged as new targets of attention. One third of the studies use neuronavigation based on anatomical magnetic resonance imaging to locate the stimulation target. After TMS intervention, discernible enhancements across a spectrum of scales are evident in stereotyped behavior, repetitive behavior, and verbal social domains. A comprehensive review of literature spanning the last five years demonstrates the potential of TMS treatment for ASD in ameliorating the clinical core symptoms.
PubMed: 38933955
DOI: 10.1016/j.heliyon.2024.e32251 -
BioRxiv : the Preprint Server For... Jun 2024In most complex nervous systems there is a clear anatomical separation between the nerve cord, which contains most of the final motor outputs necessary for behaviour,...
In most complex nervous systems there is a clear anatomical separation between the nerve cord, which contains most of the final motor outputs necessary for behaviour, and the brain. In insects, the neck connective is both a physical and information bottleneck connecting the brain and the ventral nerve cord (VNC, spinal cord analogue) and comprises diverse populations of descending (DN), ascending (AN) and sensory ascending neurons, which are crucial for sensorimotor signalling and control. Integrating three separate EM datasets, we now provide a complete connectomic description of the ascending and descending neurons of the female nervous system of and compare them with neurons of the male nerve cord. Proofread neuronal reconstructions have been matched across hemispheres, datasets and sexes. Crucially, we have also matched 51% of DN cell types to light level data defining specific driver lines as well as classifying all ascending populations. We use these results to reveal the general architecture, tracts, neuropil innervation and connectivity of neck connective neurons. We observe connected chains of descending and ascending neurons spanning the neck, which may subserve motor sequences. We provide a complete description of sexually dimorphic DN and AN populations, with detailed analysis of circuits implicated in sex-related behaviours, including female ovipositor extrusion (DNp13), male courtship (DNa12/aSP22) and song production (AN hemilineage 08B). Our work represents the first EM-level circuit analyses spanning the entire central nervous system of an adult animal.
PubMed: 38895426
DOI: 10.1101/2024.06.04.596633 -
Drug Development Research Jun 2024Schizophrenia (SZ) is a serious, destructive neurodevelopmental disorder. Antipsychotic medications are the primary therapy approach for this illness, but it's important...
Schizophrenia (SZ) is a serious, destructive neurodevelopmental disorder. Antipsychotic medications are the primary therapy approach for this illness, but it's important to pay attention to the adverse effects as well. Clinical studies for SZ are currently in phase ΙΙΙ for SEP-363856 (SEP-856)-a new antipsychotic that doesn't work on dopamine D receptors. However, the underlying action mechanism of SEP-856 remains unknown. This study aimed to evaluate the impact and underlying mechanisms of SEP-856 on SZ-like behavior in a perinatal MK-801 treatment combined with social isolation from the weaning to adulthood model (MK-SI). First, we created an animal model that resembles SZ that combines the perinatal MK-801 with social isolation from weaning to adulthood. Then, different classical behavioral tests were used to evaluate the antipsychotic properties of SEP-856. The levels of proinflammatory cytokines (tumor necrosis factor-α, interleukin-6, and interleukin-1β), apoptosis-related genes (Bax and Bcl-2), and synaptic plasticity-related genes (brain-derived neurotrophic factor [BDNF] and PSD-95) in the hippocampus were analyzed by quantitative real-time PCR. Hematoxylin and eosin staining were used to observe the morphology of neurons in the hippocampal DG subregions. Western blot was performed to detect the protein expression levels of BDNF, PSD-95, Bax, Bcl-2, PI3K, p-PI3K, AKT, p-AKT, GSK-3β, p-GSK-3β in the hippocampus. MK-SI neurodevelopmental disease model studies have shown that compared with sham group, MK-SI group exhibit higher levels of autonomic activity, stereotyped behaviors, withdrawal from social interactions, dysregulated sensorimotor gating, and impaired recognition and spatial memory. These findings imply that the MK-SI model can mimic symptoms similar to those of SZ. Compared with the MK-SI model, high doses of SEP-856 all significantly reduced increased activity, improved social interaction, reduced stereotyping behavior, reversed sensorimotor gating dysregulation, and improved recognition memory and spatial memory impairment in MK-SI mice. In addition, SEP-856 can reduce the release of proinflammatory factors in the MK-SI model, promote the expression of BDNF and PSD-95 in the hippocampus, correct the Bax/Bcl-2 imbalance, turn on the PI3K/AKT/GSK-3β signaling pathway, and ultimately help the MK-SI mice's behavioral abnormalities. SEP-856 may play an antipsychotic role in MK-SI "dual-hit" model-induced SZ-like behavior mice by promoting synaptic plasticity recovery, decreasing death of hippocampal neurons, lowering the production of pro-inflammatory substances in the hippocampal region, and subsequently initiating the PI3K/AKT/GSK-3β signaling cascade.
Topics: Animals; Schizophrenia; Proto-Oncogene Proteins c-akt; Signal Transduction; Mice; Disease Models, Animal; Phosphatidylinositol 3-Kinases; Glycogen Synthase Kinase 3 beta; Male; Neuroprotective Agents; Antipsychotic Agents; Female; Dizocilpine Maleate; Hippocampus; Behavior, Animal; Mice, Inbred C57BL; Social Isolation
PubMed: 38879781
DOI: 10.1002/ddr.22225 -
Journal of Neural Transmission (Vienna,... Jun 2024Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a phenol commonly found in grapes and wine, has been associated as protective in experimental models involving...
Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a phenol commonly found in grapes and wine, has been associated as protective in experimental models involving alterations in different neurotransmitter systems. However, studies are reporting that resveratrol could have adverse effects. This study evaluated if the association of a low dose of ketamine and resveratrol could induce behavioral manifestations associated with biochemical alterations. Moreover, the effects of treatment with resveratrol and/or ketamine on monoamine oxidase (MAO) activity, oxidative stress markers, and IL-6 levels in the brain were also investigated. Male Swiss mice received a low dose of ketamine (20 mg/kg) for 14 consecutive days, and resveratrol (10, 30, or 100 mg/kg) from day 8 up to day 14 of the experimental period, intraperitoneally. Locomotor, stereotyped behavior, Y-maze, novel recognition object test (NORT), and social interaction were quantified as well as ex vivo analysis of MAO activity, IL-6 levels, and oxidative stress markers (TBARS and total thiol levels) in brain tissues. Ketamine per se reduced the number of bouts of stereotyped behavior on day 8 of the experimental period. Resveratrol per se reduced the locomotor and exploratory activity in the open field, the time of exploration of new objects in the NORT, MAO-A activity in the striatum and increased the IL-6 levels in the cortex. These effects were attenuated when the mice were co-treated with ketamine and resveratrol. There was a decrease in MAO-A activity in the cortex of mice treated with ketamine + resveratrol 100 mg/kg. No significant alterations were found in oxidative stress markers. Resveratrol does not appear to cause summative effects with ketamine on behavioral alterations. However, the effect of resveratrol per se, mainly on locomotor and exploratory activity, should be better investigated.
PubMed: 38874765
DOI: 10.1007/s00702-024-02793-z -
Molecular Brain Jun 2024Chronic perturbations of neuronal activity can evoke homeostatic and new setpoints for neurotransmission. Using chemogenetics to probe the relationship between neuronal...
Chronic perturbations of neuronal activity can evoke homeostatic and new setpoints for neurotransmission. Using chemogenetics to probe the relationship between neuronal cell types and behavior, we recently found reversible decreases in dopamine (DA) transmission, basal behavior, and amphetamine (AMPH) response following repeated stimulation of DA neurons in adult mice. It is unclear, however, whether altering DA neuronal activity via chemogenetics early in development leads to behavioral phenotypes that are reversible, as alterations of neuronal activity during developmentally sensitive periods might be expected to induce persistent effects on behavior. To examine the impact of developmental perturbation of DA neuron activity on basal and AMPH behavior, we expressed excitatory hM3D(Gq) in postnatal DA neurons in TH-Cre and WT mice. Basal and CNO- or AMPH-induced locomotion and stereotypy was evaluated in a longitudinal design, with clozapine N-oxide (CNO, 1.0 mg/kg) administered across adolescence (postnatal days 15-47). Repeated CNO administration did not impact basal behavior and only minimally reduced AMPH-induced hyperlocomotor response in adolescent TH-Cre mice relative to WT littermate controls. Following repeated CNO administration, however, AMPH-induced stereotypic behavior robustly decreased in adolescent TH-Cre mice relative to controls. A two-month CNO washout period rescued the diminished AMPH-induced stereotypic behavior. Our findings indicate that the homeostatic compensations that take place in response to chronic hM3D(Gq) stimulation during adolescence are temporary and are dependent on ongoing chemogenetic stimulation.
Topics: Animals; Amphetamine; Dopaminergic Neurons; Stereotyped Behavior; Clozapine; Locomotion; Mice; Male; Motor Activity; Mice, Transgenic; Tyrosine 3-Monooxygenase; Behavior, Animal; Integrases
PubMed: 38858755
DOI: 10.1186/s13041-024-01110-9 -
Molecular Neurobiology Jun 2024CELF2 variants have been linked to neurodevelopmental disorders (NDD), including autism spectrum disorder (ASD). However, the molecular mechanisms remain unclear. We...
CELF2 variants have been linked to neurodevelopmental disorders (NDD), including autism spectrum disorder (ASD). However, the molecular mechanisms remain unclear. We generated Celf2 Nestin-Cre knockout mice.Our findings revealed that Celf2 Nestin-Cre heterozygous knockout mice exhibited social impairment and anxiety, an autism-like behavior, though no manifestations of repetitive stereotyped behavior, learning cognitive impairment, or depression were observed. Immunofluorescence assay showed an underdeveloped cerebral cortex with significantly reduced cortical thickness, albeit without abnormal cell density. Further in vitro neuronal culture demonstrated a significant reduction in dendritic spine density and affected synaptic maturation in Celf2 deficient mice, with no notable abnormalities in total neurite and axon length. RNA-seq and RIP-seq analysis of the cerebral cortex revealed differentially expressed genes post Celf2 gene knockout compared with the control group. Enrichment analysis highlighted significant enrichment in dendrite and synapse-related biological processes and pathways. Our study delineated the behavioral and neurodevelopmental phenotypes of Celf2, suggesting its potential involvement in autism through the regulation of target genes associated with dendritic spines and synapse development. Further research is needed to elucidate the specific mechanisms involved.
PubMed: 38829512
DOI: 10.1007/s12035-024-04250-0 -
Behavior Modification May 2024Complex motor stereotypies are rhythmic, repetitive, fixed, and non-goal directed movements (e.g., bilateral flapping/waving movements of the hands/arms). Movements...
Complex motor stereotypies are rhythmic, repetitive, fixed, and non-goal directed movements (e.g., bilateral flapping/waving movements of the hands/arms). Movements typically begin in early childhood and can occur in otherwise normally developing ("primary") or autistic ("secondary") children. Stereotypies persist, occur multiple times a day, have prolonged durations, can be socially stigmatizing, and may lead to bullying and isolation. Prior behavioral treatment studies have focused on older children (ages 6-12) and report modest reductions in stereotypy (i.e., between 14% and 33%). The current study involves the functional assessment and treatment of five children with Primary Complex Motor Stereotypy using a modified awareness training procedure, differential reinforcement of other behavior, and schedule thinning in a nonconcurrent multiple baseline design. Results suggest a 99% reduction of motor stereotypy from baseline across all participants.
PubMed: 38819977
DOI: 10.1177/01454455241255085 -
Journal of Psychiatric Practice May 2024Catatonia is a complex syndrome with unique cognitive, psychomotor, and mood features. Mannerisms and stereotypies are catatonic signs that have been extensively...
Catatonia is a complex syndrome with unique cognitive, psychomotor, and mood features. Mannerisms and stereotypies are catatonic signs that have been extensively observed and described in the literature, mostly in the context of movements or motor acts. Stereotypies are commonly described as repetitive psychomotor or verbal acts with the abnormality not inherent in the act but in its frequency. Mannerisms, like stereotypies, are repetitive psychomotor or verbal acts, but they are fundamentally odd in nature. Recently, several reports have described these phenomena in the context of complex behaviors, such as eating and drinking. Identification and appreciation of personal and cultural norms, in addition to a careful analysis of behavioral processes and actions, are important tools for clinicians to identify these potentially elusive and often missed patterns of behavior in patients with catatonia. We present the case of a 30-year-old male with a psychiatric history of treatment-resistant, recurrent major depressive disorder with psychotic features who presented to the inpatient psychiatric unit with signs of catatonia, including repeated, purposeless eating. The patient's chart was reviewed, and a literature review was conducted using PubMed with the keywords catatonia, stereotypies, mannerisms, and hyperphagia. The patient, who was diagnosed with catatonia and expressed hyperphagia as a stereotypy, responded to lorazepam. This case shows that hyperphagia may present as a stereotypy in patients with catatonia.
Topics: Humans; Catatonia; Male; Hyperphagia; Adult; Stereotyped Behavior; Depressive Disorder, Major; Lorazepam
PubMed: 38819249
DOI: 10.1097/PRA.0000000000000786