Chronic exposure to cyclohexane induces stereotypic circling, hyperlocomotion, and anxiety-like behavior associated with atypical c-Fos expression in motor- and anxiety-related brain regions.

Recreational abuse of solvents continues, despite cyclohexane (CHX) is used as a safe replacement in gasoline or adhesive formulations. Increasing evidence indicates that CHX inhalation affects brain functioning; however, scanty information is available about its effects on behavior and brain activity upon drug removal. In this study, we used CD1 adult mice to mimic an intoxication period of recreational drugs for 30 days. During the CHX exposure (~30,000 ppm), we analyzed exploratory and biphasic behaviors, stereotypic circling, and locomotion. After CHX removal (24 h or a month later), we assessed anxiety-like behaviors and quantified c-Fos cells in motor- and anxiety-related brain regions. Our findings indicate that the repeated inhalation of CHX produced steady hyperactivity and reduced ataxia, sedation, and seizures as the exposure to CHX progressed. Also, CHX decreased grooming and rearing behaviors. In the first week of CHX inhalation, a stereotypic circling behavior emerged, and locomotion increased gradually. One month after CHX withdrawal, mice showed low activity in the center zone of the open field and more buried marbles. Twenty-four hours after CHX removal, c-Fos expression was low in the dorsal striatum, ventral striatum, motor cortex, dorsomedial prefrontal cortex, basolateral amygdala, lateral hypothalamus, and ventral hippocampus. One month later, c-Fos expression remained low in the ventral striatum and lateral hypothalamus but increased in the dorsomedial prefrontal cortex and primary motor cortex. This study provides a comprehensive behavioral characterization and novel histological evidence of the CHX effects on the brain when is administered in a recreational-like mode.

Quantified assessment of hyperactivity in ADHD youth using IR-UWB radar.

Research on the quantification of hyperactivity in youth with attention-deficit/hyperactivity disorder (ADHD) has been limited and inconsistent. The purpose of this study was to test the discriminative value of impulse-radio ultra-wideband (IR-UWB) radar for monitoring hyperactive individuals with ADHD and healthy controls (HCs). A total of 10 ADHD patients and 15 HCs underwent hyperactivity assessment using IR-UWB radar during a 22-min continuous performance test. We applied functional ANOVA to compare the mean functions of activity level between the 2 groups. We found that the mean function of activity over time was significantly different and that the activity level of the ADHD group slightly increased over time with high dispersion after approximately 7 min, which means that the difference in activity level between the two groups became evident at this period. Further studies with larger sample sizes and longer test times are warranted to investigate the effect of age, sex, and ADHD subtype on activity level function.

Elimination of the Cortico-Subthalamic Hyperdirect Pathway Induces Motor Hyperactivity in Mice.

The substantia nigra pars reticulata (SNr) is the output station of the basal ganglia and receives cortical inputs by way of the following three basal ganglia pathways: the cortico-subthalamo (STN)-SNr hyperdirect, the cortico-striato-SNr direct, and the cortico-striato-external pallido-STN-SNr indirect pathways. Compared with the classical direct and indirect pathways via the striatum, the functions of the hyperdirect pathway remain to be fully elucidated. Here we used a photodynamic technique to selectively eliminate the cortico-STN projection in male mice and observed neuronal activity and motor behaviors in awake conditions. After cortico-STN elimination, cortically evoked early excitation in the SNr was diminished, while the cortically evoked inhibition and late excitation, which are delivered through the direct and indirect pathways, respectively, were unchanged. In addition, locomotor activity was significantly increased after bilateral cortico-STN elimination, and apomorphine-induced ipsilateral rotations were observed after unilateral cortico-STN elimination, suggesting that cortical activity was increased. These results are compatible with the notion that the cortico-STN-SNr hyperdirect pathway quickly conveys cortical excitation to the output station of the basal ganglia, resets or suppresses the cortical activity related to ongoing movements, and prepares for the forthcoming movement.SIGNIFICANCE STATEMENT The basal ganglia play a pivotal role in the control of voluntary movements, and their malfunctions lead to movement disorders, such as Parkinson's disease and dystonia. Understanding their functions is important to find better treatments for such diseases. Here we used a photodynamic technique to selectively eliminate the projection from the motor cortex to the subthalamic nucleus, the input station of the basal ganglia, and found greatly reduced early excitatory signals from the cortex to the output station of the basal ganglia and motor hyperactivity. These results suggest that the neuronal signals through the cortico-subthalamic hyperdirect pathway reset or suppress ongoing movements and that blockade of this pathway may be beneficial for Parkinson's disease, which is characterized by oversuppression of movements.

Conveyance of cortical pacing for parkinsonian tremor-like hyperkinetic behavior by subthalamic dysrhythmia.

Parkinson's disease is characterized by both hypokinetic and hyperkinetic symptoms. While increased subthalamic burst discharges have a direct causal relationship with the hypokinetic manifestations (e.g., rigidity and bradykinesia), the origin of the hyperkinetic symptoms (e.g., resting tremor and propulsive gait) has remained obscure. Neuronal burst discharges are presumed to be autonomous or less responsive to synaptic input, thereby interrupting the information flow. We, however, demonstrate that subthalamic burst discharges are dependent on cortical glutamatergic synaptic input, which is enhanced by A-type K+ channel inhibition. Excessive top-down-triggered subthalamic burst discharges then drive highly correlative activities bottom-up in the motor cortices and skeletal muscles. This leads to hyperkinetic behaviors such as tremors, which are effectively ameliorated by inhibition of cortico-subthalamic AMPAergic synaptic transmission. We conclude that subthalamic burst discharges play an imperative role in cortico-subcortical information relay, and they critically contribute to the pathogenesis of both hypokinetic and hyperkinetic parkinsonian symptoms.

Iron overload during the embryonic period develops hyperactive like behavior and dysregulation of biogenic amines in Drosophila melanogaster.

Iron (Fe) is used in various cellular functions, and a constant balance between its uptake, transport, storage, and use is necessary to maintain its homeostasis in the body. Changes in Fe metabolism with a consequent overload of this metal are related to neurological changes and cover a broad spectrum of diseases, mainly when these changes occur during the embryonic period. This work aimed to evaluate the effect of exposure to Fe overload during the embryonic period of Drosophila melanogaster. Progenitor flies (male and female) were exposed to ferrous sulfate (FeSO4) for ten days in concentrations of 0.5, 1, and 5 â€‹mM. After mating and oviposition, the progenitors were removed and the treatment bottles preserved, and the number of daily hatches and cumulative hatching of the first filial generation (F1) were counted. Subsequently, F1 flies (separated by sex) were subjected to behavioral tests such as negative geotaxis test, open field test, grooming, and aggression test. They have evaluated the levels of dopamine (DA), serotonin (5-HT), octopamine (OA), tryptophan and tyrosine hydroxylase (TH), acetylcholinesterase, reactive species, and the levels of Fe in the progenitor flies and F1. The Fe levels of F1 flies are directly proportional to what is incorporated during the period of embryonic development; we also observed a delay in hatching and a reduction in the number of the hatch of F1 flies exposed during the embryonic period to the 5mM Fe diet, a fact that may be related to the reduction of the cell viability of the ovarian tissue of progenitor flies. The flies exposed to Fe (1 and 5 â€‹mM) showed an increase in locomotor activity (hyperactivity) and a significantly higher number of repetitive movements. In addition to a high number of aggressive encounters when compared to control flies. We can also observe an increase in the levels of biogenic amines DA and 5-HT and an increase in TH activity in flies exposed to Fe (1 and 5 â€‹mM) compared to the control group. We conclude that the hyperactive-like behavior demonstrated in both sexes by F1 flies exposed to Fe may be associated with a dysregulation in the levels of DA and 5-HT since Fe is a cofactor of TH, which had its activity increased in this study. Therefore, more attention is needed during the embryonic development period for exposure to Fe overload.

Abnormal neurodevelopment outcome in case of neonatal hyperekplexia secondary to missense mutation in GLRB gene.

Hyperekplexia is an exaggerated startle to external stimuli associated with a generalised increase in tone seen in neonates with both sporadic and genetic predisposition. This is an uncommon neurological entity that is misdiagnosed as seizure. A 28-days-old infant was admitted to us with characteristic intermittent generalised tonic spasm being treated as a seizure disorder. The infant had characteristic stiffening episode, exaggerated startle and non-habituation on tapping the nose. Hyperekplexia was suspected and confirmed by genetic testing (mutation in the ß subunit of glycine was found). Initial improvement was seen with the use of clonazepam, which was not sustained. At the age of 4.5 years, the child is still having neurobehavioural issues like hyperactivity and sensory hyper-responsiveness. Usually, hyperekplexia is benign in nature. We report a case of hyperekplexia with non-sense mutation in the ß subunit of GlyR gene having abnormal neurodevelopmental findings at 4.5 years.

A movement disorder specialist gets a taste of his own medicine.

We present a case in which a movement disorder neurologist developed two different hyperkinetic movements due to corticospinal tract hyperexcitability, which resolved completely with surgical removal of an epidural spinal canal tumor. The first-hand description of these movements creates a unique opportunity for enhanced insight into these complex movement phenomena.

Investigation of networks underlying hyperkinetic seizures utilizing ictal SPECT.

OBJECTIVE: To study neural networks involved in hyperkinetic seizures (HKS) using ictal SPECT. METHODS: We retrospectively identified 18 patients with HKS evaluated at the Cleveland Clinic between 2005 and 2015 with video-EEG monitoring and ictal SPECT. Semiology was confirmed by the consensus of 2 epileptologists' independent reviews and classified as type 1, 2, or 3 HKS. SPECT data were analyzed by 2 independent physicians using a z score of 1.5. Ictal hyperperfusion patterns for each group were analyzed visually and with SPM. Spatial normalization to Montreal Neurological Institute space for each patient's data was performed, followed by flipping of data from patients with left-sided ictal onset to the right side. Finally, an average z score map for each group was calculated. RESULTS: Visual analysis and SPM identified different patterns of ictal hyperperfusion in the 3 subtypes of HKS. Type 1 seizures showed hyperperfusion in a more anteriorly located network involving the anterior insula, orbitofrontal cortex, cingulate, and anterior perisylvian region and rostral midbrain. Type 2 seizures were associated with hyperperfusion in a more caudally located network involving the orbitofrontal cortex, cingulate (middle and posterior), basal ganglia, thalami, and cerebellum. Type 3 seizures showed a mixed pattern of SPECT hyperperfusion involving the temporal pole and anterior perisylvian region. CONCLUSIONS: Each of the 3 different semiologic subtypes of HKS is associated with distinct patterns of hyperperfusion, providing further insight into the neural networks involved. This knowledge may inform placement of invasive EEG electrodes in patients with HKS semiology undergoing presurgical evaluation.

Effects of non-peptide nociceptin/orphanin FQ receptor ligands on methylphenidate-induced hyperactivity in mice: Implications for bipolar disorders.

Bipolar disorder is a psychiatric pathology characterized by biphasic mood episodes of mania or hypomania and depression. The pharmacotherapy of bipolar disorder has significant adverse effects impairing treatment adherence and patient quality of life. The N/OFQ-NOP receptor system has been widely implicated with mood disorders. Clinical and preclinical findings suggest antidepressants actions for NOP antagonists. More recently, the administration of NOP agonists has shown to promote depressant states. The present study aimed to investigate the effects of non-peptide NOP ligands in methylphenidate-induced manic-like behavior in mice. The NOP agonist Ro 65-6570 (0.01-1 mg/kg, ip), at the higher dose, did not affect spontaneous locomotion per se, but prevented the methylphenidate (10 mg/kg, sc)-induced hyperlocomotion. The NOP partial agonist AT-090 (0.001-0.03 mg/kg, ip) and the NOP antagonist SB-612111 (1-10 mg/kg, ip) did not significantly affect the psychostimulant-induced hyperactivity. Experiments performed with mice lacking the NOP receptor (NOP(-/-)) demonstrated that the treatment with methylphenidate induced similar hyperlocomotion in NOP(-/-) and NOP(+/+) mice. In conclusion, these findings suggest a potential role for NOP agonists in the prevention of manic states, especially by counteracting the hyperactivity symptom of bipolar patients. However, more studies are necessary in order to evaluate these compounds in other features of bipolar disorder.

Motor hyperactivation during cognitive tasks: An endophenotype of juvenile myoclonic epilepsy.

OBJECTIVE: Juvenile myoclonic epilepsy (JME) is the most common genetic generalized epilepsy syndrome. Myoclonus may relate to motor system hyperexcitability and can be provoked by cognitive activities. To aid genetic mapping in complex neuropsychiatric disorders, recent research has utilized imaging intermediate phenotypes (endophenotypes). Here, we aimed to (a) characterize activation profiles of the motor system during different cognitive tasks in patients with JME and their unaffected siblings, and (b) validate those as endophenotypes of JME. METHODS: This prospective cross-sectional investigation included 32 patients with JME, 12 unaffected siblings, and 26 controls, comparable for age, sex, handedness, language laterality, neuropsychological performance, and anxiety and depression scores. We investigated patterns of motor system activation during episodic memory encoding and verb generation functional magnetic resonance imaging (fMRI) tasks. RESULTS: During both tasks, patients and unaffected siblings showed increased activation of motor system areas compared to controls. Effects were more prominent during memory encoding, which entailed hand motion via joystick responses. Subgroup analyses identified stronger activation of the motor cortex in JME patients with ongoing seizures compared to seizure-free patients. Receiver-operating characteristic curves, based on measures of motor activation, accurately discriminated both patients with JME and their siblings from healthy controls (area under the curve: 0.75 and 0.77, for JME and a combined patient-sibling group against controls, respectively; P < .005). SIGNIFICANCE: Motor system hyperactivation represents a cognitive, domain-independent endophenotype of JME. We propose measures of motor system activation as quantitative traits for future genetic imaging studies in this syndrome.

In vivo evaluation of effects of histamine H3 receptor antagonists on methamphetamine-induced hyperlocomotion in mice.

A single administration with METH (3 mg/kg) induced a hyperlocomotion in male ICR mice. Pretreatment of mice with pitolisant, a histamine H3 receptor antagonist (5 and 10 mg/kg), for 30 min showed a significant reduction of the hyperlocomotion induced by METH, as compared with vehicle (saline)-pretreated subjects. Pretreatment of mice with the histamine H3 receptor antagonists JNJ-10181457 (5 and 10 mg/kg) or conessine (20 mg/kg), also showed similar inhibitory effects on METH-induced hyperlocomotion, similar to pitolisant. No significant change in locomotion was observed in mice pretreated with pitolisant, JNJ-10181457, or conessine alone. The pitolisant (10 mg/kg) action on METH-induced hyperlocomotion was completely abolished by the histamine H1 receptor antagonist pyrilamine (10 mg/kg), but not by the peripherally acting histamine H1 receptor antagonist fexofenadine (20 mg/kg), the brain-penetrating histamine H2 receptor antagonist zolantidine (10 mg/kg), or the brain-penetrating histamine H4 receptor antagonist JNJ-7777120 (40 mg/kg). Pretreatment with a histamine H3 receptor agonist immepip (10 mg/kg) augmented METH--induced behavior, including hyperlocomotion and stereotyped biting, and combined pretreatment with pitolisant (10 mg/kg) significantly attenuated stereotyped biting. These observations suggest that pretreatment with histamine H3 receptor antagonists attenuate METH-induced hyperlocomotion via releasing histamine after blocking H3 receptors, which then bind to the post-synaptic histamine receptor H1 (but not H2 or H4). It is likely that activation of brain histamine systems may be a good strategy for the development of agents, which treat METH abuse and dependence.

Quantitative analysis of hyperkinetic seizures and correlation with seizure onset zone.

OBJECTIVE: Hyperkinetic epileptic seizures (HKS) are difficult to characterize and localize according to semiologic features. We propose a multicriteria scale to help visual analysis and report results of cerebral localization. METHODS: We assessed seizures from 37 patients with HKS, explored with stereoelectroencephalography during presurgical evaluation. We used a multicriteria scale (hyperkinetic seizure scale [HSS]) with 10 semiologic features, scored independently by two neurologists. The item scores were used to group seizures using the k-means method. Semiologic features were correlated with the seizure onset zone (SOZ) localization (temporal, prefrontal dorsolateral, prefrontal ventromesial, parietal, insular). RESULTS: Fifty-five seizures were analyzed, and each item of the HSS was compared between the two examiners with good interrater agreement (85.3%). Dystonia, integrated behavior, and bilateral or unilateral hyperkinetic movements were statistically significant according to localization. Three clusters were identified according to the HSS and correlated with different patterns of anatomic localization of SOZ. Cluster 1 was characterized clinically by asymmetric hyperkinetic movements associated with marked dystonia and vocalization. It mainly included parietal seizures. Cluster 2 was characterized by bilateral and symmetrical stereotyped hyperkinetic movements without dystonia. It represented half of temporal seizures and one-third of prefrontal seizures (dorsolateral). Cluster 3 was characterized by seizures with strong emotionality and vocalization with bilateral and symmetrical hyperkinetic movements and integrated behavior. It involved half of temporal seizures and a majority of prefrontal (ventromesial) seizures. SIGNIFICANCE: We propose a first attempt to quantify clinical patterns of HKS. The HSS may help to predict SOZ localization according to three main groups of hyperkinetic seizures.

REM-sleep related hypermotor seizures: Video documentation and ictal source imaging.

INTRODUCTION: Rapid eye movement (REM) sleep has an inhibitory effect on epileptiform EEG discharges, and seizures occur extremely rarely in REM sleep. CASE STUDY: We present the case and video recordings of a 10-year-old boy, with sleep-related hypermotor seizures starting from REM sleep, identified from videoEEG recordings. The semiology comprised intense fear, tachycardia, tachypnea, followed by hypermotor manifestations. Further investigations included brain MRI and source localization of the EEG signals. Multiple antiepileptic drugs were tried, the patient obtaining a good control of the seizures in the last 2.5 years with eslicarbazepine. DISCUSSION AND CONCLUSION: The ictal EEG source imaging showed seizure onset in the anterior part of the right insula, with propagation to the orbitofrontal area, confirmed by the semiological sequence. Although rare, focal seizures can be triggered by REM sleep and our findings suggest that deficient maturation of brain areas involved in sleep modulation might induce insufficient desynchronization during REM sleep, thus allowing seizure emergence.

Basal ganglia oscillations as biomarkers for targeting circuit dysfunction in Parkinson's disease.

Oscillations are a naturally occurring phenomenon in highly interconnected dynamical systems. However, it is thought that excessive synchronized oscillations in brain circuits can be detrimental for many brain functions by disrupting neuronal information processing. Because synchronized basal ganglia oscillations are a hallmark of Parkinson's disease (PD), it has been suggested that aberrant rhythmic activity associated with symptoms of the disease could be used as a physiological biomarker to guide pharmacological and electrical neuromodulatory interventions. We here briefly review the various manifestations of basal ganglia oscillations observed in human subjects and in animal models of PD. In this context, we also review the evidence supporting a pathophysiological role of different oscillations for the suppression of voluntary movements as well as for the induction of excessive motor activity. In light of these findings, it is discussed how oscillations could be used to guide a more precise targeting of dysfunctional circuits to obtain improved symptomatic treatment of PD.

The unique expression profile of FAM19A1 in the mouse brain and its association with hyperactivity, long-term memory and fear acquisition.

Neurodevelopment and mature brain function are spatiotemporally regulated by various cytokines and chemokines. The chemokine-like neuropeptide FAM19A1 is a member of family with sequence similarity 19 (FAM19), which is predominantly expressed in the brain. Its highly conserved amino acid sequence among vertebrates suggests that FAM19A1 may play important physiological roles in neurodevelopment and brain function. Here we used a LacZ reporter gene system to map the expression pattern of the FAM19A1 gene in the mouse brain. The FAM19A1 expression was observed in several brain regions starting during embryonic brain development. As the brain matured, the FAM19A1 expression was detected in the pyramidal cells of cortical layers 2/3 and 5 and in several limbic areas, including the hippocampus and the amygdala. FAM19A1-deficient mice were used to evaluate the physiological contribution of FAM19A1 to various brain functions. In behavior analysis, FAM19A1-deficient mice exhibited several abnormal behaviors, including hyperactive locomotor behavior, long-term memory deficits and fear acquisition failure. These findings provide insight into the potential contributions of FAM19A1 to neurodevelopment and mature brain function.

Progressive supranuclear palsy presenting with hyperkinetic movement disorder and hemiplegic dystonia: a case report.

Background: Progressive supranuclear palsy (PSP) is a progressive neurodegenerative brain disease which has been rarely described in association with hyperkinetic symptoms. Here, we report a case of PSP that was presented with hyperkinetic movement disorder, hemiplegic dystonia, and other clinical features that overlap with behavioral variant frontotemporal dementia (bvFTD) and corticobasal syndrome (CBS).Case presentation: A 63-year-old female presented to our hospital with a history of frontal lobe symptoms, impaired cognition, hyperkinetic movement disorders, dystonia, and frequent falls. Her magnetic resonance imaging (MRI) scan showed atrophy of midbrain and right temporal lobe. [18F]FDG PET result revealed reduced 18F-FDG uptake with obvious laterality (right > left). [18F]THK5317 PET scan showed evident increased uptake in the brain stem and basal ganglia. Treatment with Tiapride significantly improved hyperkinetic symptoms, but other motor symptoms were not alleviated. Three years later, the patient could hardly walk even with assistance.Conclusion: PSP can present hyperkinetic movement disorders and asymmetry in image that widen the existing phenotypic spectrum.

Real world use of a neurophysiology service for the differential diagnosis of hyperkinetic movement disorders.

INTRODUCTION: Clinical neurophysiology constitutes a potentially useful aid in differentiating hyperkinetic movement disorders (HMD). Parameters including presence of a Bereitschaftspotential on back-averaged electroencephalography (EEG) have been demonstrated to help distinguish between these disorders. In 2008, a Movement Disorder neurophysiology service was established in Greater Manchester to aid in the diagnostic process. METHODS: We retrospectively reviewed records of patients with HMD who underwent EEG back-averaging through this service from January 2009 until January 2018. The aim was (i) to characterise the clinical features of our patient cohort and (ii) to determine how frequently neurophysiological testing altered the final diagnosis. RESULTS: A total of 39 patients (23 females, 16 males), with a mean age at onset of 42.6 years and mean disease duration of 2.0 years underwent neurophysiological examination. The clinical diagnosis was changed in 16 cases (41%) and refined in a further seven. Distractibility (P = 0.001), variability (P = 0.002), the presence of a Bereitschaftspotential (P < 0.0001), and electromyography burst duration > 300 ms (P = 0.012) were more frequent in those with an eventual diagnosis of functional movement disorder (n = 24) compared to other HMDs (n = 15). CONCLUSION: Neurophysiology is an invaluable adjunct in complex HMD, altering the diagnosis and treatment options for a significant proportion of patients. Our data also demonstrate, consistent with previous studies, that the majority of patients referred for jerky HMDs to a tertiary movement disorder service have a functional movement disorder.

Interaction of reelin and stress on immobility in the forced swim test but not dopamine-mediated locomotor hyperactivity or prepulse inhibition disruption: Relevance to psychotic and mood disorders.

RATIONALE: Psychotic disorders, such as schizophrenia, as well as some mood disorders, such as bipolar disorder, have been suggested to share common biological risk factors. One such factor is reelin, a large extracellular matrix glycoprotein that regulates neuronal migration during development as well as numerous activity-dependent processes in the adult brain. The current study sought to evaluate whether a history of stress exposure interacts with endogenous reelin levels to modify behavioural endophenotypes of relevance to psychotic and mood disorders. METHODS: Heterozygous Reeler Mice (HRM) and wildtype (WT) controls were treated with 50mg/L of corticosterone (CORT) in their drinking water from 6 to 9weeks of age, before undergoing behavioural testing in adulthood. We assessed methamphetamine-induced locomotor hyperactivity, prepulse inhibition (PPI) of acoustic startle, short-term spatial memory in the Y-maze, and depression-like behaviour in the Forced-Swim Test (FST). RESULTS: HRM genotype or CORT treatment did not affect methamphetamine-induced locomotor hyperactivity, a model of psychosis-like behaviour. At baseline, HRM showed decreased PPI at the commonly used 100msec interstimulus interval (ISI), but not at the 30msec ISI or following challenge with apomorphine. A history of CORT exposure potentiated immobility in the FST amongst HRM, but not WT mice. In the Y-maze, chronic CORT treatment decreased novel arm preference amongst HRM, reflecting reduced short-term spatial memory. CONCLUSION: These data confirm a significant role of endogenous reelin levels on stress-related behaviour, supporting a possible role in both bipolar disorder and schizophrenia. However, an interaction of reelin deficiency with dopaminergic regulation of psychosis-like behaviour remains unclear.