Abnormal phospholipid metabolism has been implicated in the pathogenesis of schizophrenia, and it was reported that phospholipase C (PLC) beta1 is reduced in specific brain areas of patients with schizophrenia. However, the causal relationship of the PLCbeta1 gene with behavioral symptoms of schizophrenia remains unclear. To address this issue, we have examined the mutant mice ...

Stress is suggested to exacerbate symptoms and contribute to relapse in patients with schizophrenia and several other psychiatric disorders. A prominent feature of many of these illnesses is an impaired ability to filter information through sensorimotor gating processes. Prepulse inhibition (PPI) is a functional measure of sensorimotor ...

Tauopathies are neurodegenerative disorders characterized by the accumulation of abnormal tau protein leading to cognitive and/or motor dysfunction. To understand the relationship between tau pathology and behavioral impairments, we comprehensively assessed behavioral abnormalities in a mouse tauopathy model expressing the human P301S mutant tau protein in ...

ObjectivesMaternal infection during pregnancy increases risk of severe neuropsychiatric disorders, including schizophrenia and autism, in the offspring. The most consistent brain structural abnormality in patients with schizophrenia is enlarged lateral ventricles. However, it is unknown whether the aetiology of ventriculomegaly in schizophrenia involves prenatal infectious ...

A deficit in prepulse inhibition (PPI) can be one of the clinically observed features of post-traumatic stress disorder (PTSD) that is seen long after the acute traumatic episode has terminated. Thus, reduced PPI may represent an enduring psychophysiological marker of this illness in some patients. PPI is an operational measure of sensorimotor gating and ...

Autism spectrum disorder (ASD) is diagnosed based on three core features: impaired social interactions, deficits in communication and repetitive or restricted behavioral patterns. Against this backdrop, abnormal sensory processing receives little attention despite its prevalence and the impact it exerts on the core diagnostic features. Understanding the source of these sensory ...

Deficits in an operational measure of sensorimotor gating - the prepulse inhibition of startle (PPI) - are presented in psychiatric disorders such as schizophrenia, bipolar disorder, and attention deficit/hyperactivity disorder (ADHD). Some previous studies showed that the spontaneously hypertensive rats (SHR) present PPI deficit. Although SHR is suggested ...

Prepulse inhibition (PPI) may useful for exploring the proposed shared neurobiology between idiopathic autism and autism caused by FXS. We compared PPI in four groups: typically developing controls (n�=�18), FXS and autism (FXS+A; n�=�15), FXS without autism spectrum disorder (FXS?A; n�=�17), and idiopathic autism (IA; n�=�15). Relative to controls, the FXS+A (p�<�0.002) and ...

Prepulse inhibition (PPI) may useful for exploring the proposed shared neurobiology between idiopathic autism and autism caused by FXS. We compared PPI in four groups: typically developing controls (n = 18), FXS and autism (FXS+A; n = 15), FXS without autism spectrum disorder (FXS-A; n = 17), and idiopathic autism (IA; n = 15). Relative to controls, the FXS+A (p less than 0.002) and FXS-A (p less ...

Abstract Dopaminergic mechanisms have been theorized to influence hypnotizability and sensorimotor gating. In this study, the authors investigated an association between sensorimotor gating, as measured by prepulse inhibition (PPI), and hypnotizability, as assessed by the Stanford Hypnotic Susceptibility Scale, ...

Early mechanisms to limit the input of sensory information to higher brain areas are important for a healthy individual. In previous studies, we found that a low dose of 10mg escitalopram (SSRI) disrupts habituation, without affecting sensory and sensorimotor gating in healthy volunteers. In the current study a higher dose of 15 mg was used. The hypothesis ...

Several presynaptic proteins involved in neurotransmitter release in the central nervous system have been implicated in schizophrenia in human clinical genetic studies, in post-mortem studies, and in studies of putative animal models of schizophrenia. The presynaptic protein RIM1? mediates presynaptic plasticity and cognitive function. We now demonstrate that mice deficient in RIM1? exhibit ...

Autism is a highly variable brain developmental disorder and has a strong genetic basis. Pax6 is a pivotal player in brain development and maintenance. It is expressed in embryonic and adult neural stem cells, in astrocytes in the entire central nervous system, and in neurons in the olfactory bulb, amygdala, thalamus, and cerebellum, functioning in highly context-dependent manners. We have ...

Autism is a highly variable brain developmental disorder and has a strong genetic basis. Pax6 is a pivotal player in brain development and maintenance. It is expressed in embryonic and adult neural stem cells, in astrocytes in the entire central nervous system, and in neurons in the olfactory bulb, amygdala, thalamus, and cerebellum, functioning in highly context-dependent manners. We have ...

Abstract Objectives. Recent evidence is reviewed to examine relationships among sensorimotor and cognitive aspects in some important psychiatry disorders. This study reviews the theoretical models in the context of sensorimotor integration and the abnormalities reported in the most common psychiatric disorders, such as Alzheimer's ...

ganglia also play a critical role in sensorimotor function. Furthermore, the basal ganglia are prominently working hypothesis is that abnormal plasticity in the basal ganglia is a critical link between . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559 Basal ganglia network

Prepulse inhibition (PPI) is an operational measure of sensorimotor gating that is thought to probe preattentional filtering mechanisms. PPI is deficient in several neuropsychiatric disorders, possibly reflecting abnormalities in frontal-cortical-striatal circuitry. Several studies support the predictive validity of animal PPI to model ...

The kinetic behavior of brain Na+ channels was studied in pyramidal cells from rat and cat sensorimotor cortex using either the thin slice preparation or acutely isolated neurons. Single-channel recordings were obtained in the cell-attached and inside-out...

A variety of features of autism can be simulated in rodents, including the core behavioral hallmarks of stereotyped and repetitive behaviors, and deficits in social interaction and communication. Other behaviors frequently found in autism spectrum disorders (ASDs) such as neophobia, enhanced anxiety, abnormal pain sensitivity and eye blink conditioning, disturbed sleep ...

Here, we report generation and characterization of Disrupted-In-Schizophrenia-1 (DISC1) genetically engineered mice as a potential model for major mental illnesses, such as schizophrenia. DISC1 is a promising genetic risk factor for major mental illnesses. In this transgenic model, a dominant-negative form of DISC1 (DN-DISC1) is expressed under the ?CaMKII promoter. In vivo MRI of the DN-DISC1 ...

C57BL/6 mice were given 0.2% cuprizone (CPZ) for 2 to 6 weeks while controls ate the same diet without CPZ. At various time points the animals were subjected to behavioral tests and their brains were analyzed. Mice exposed to CPZ for 2 and 3 weeks displayed more climbing behavior and lower prepulse inhibition, suggesting an increase in central nervous system activity and impaired ...

Restless Legs Syndrome (RLS) is a sensori-motor disorder characterized by unpleasant, abnormal feelings in the legs and occasionally arms which occur at rest and when initiating sleep. The sufferer experiences an uncontrollable urge to move in order to re...

Dystonia is characterised by two main pathophysiological abnormalities: reduced excitability of inhibitory systems at many levels of the sensorimotor system, and increased plasticity of neural connections in sensorimotor circuits at a brainstem and spinal level. A surprising finding in two recent papers has been the fact that ...

The G protein-coupled receptor (GPCR) family is highly diversified and involved in many forms of information processing. SREB2 (GPR85) is the most conserved GPCR throughout vertebrate evolution and is expressed abundantly in brain structures exhibiting high levels of plasticity, e.g., the hippocampal dentate gyrus. Here, we show that SREB2 is involved in determining brain size, modulating diverse ...

The genes in the imprinted cluster on human chromosome 15q11-q13 are known to contribute to psychiatric conditions such as schizophrenia and autism. Major disruptions of this interval leading to a lack of paternal allele expression give rise to Prader-Willi syndrome (PWS), a neurodevelopmental disorder with core symptoms of a failure to thrive in infancy and, on emergence from infancy, learning ...

Dystonia is a functionally disabling movement disorder characterized by abnormal movements and postures. Although substantial recent progress has been made in identifying genetic factors, the pathophysiology of the disease remains a mystery. A provocative suggestion gaining broader acceptance is that some aspect of neural plasticity may be abnormal. There ...

The aim of this study was to analyze the prevalence and severity of sensorimotor and autonomic neuropathic symptoms within an outpatients diabetic population. A total of 350 consecutive Type 1 (26.9%) and Type 2 diabetic subjects were investigated using the Michigan Neuropathy Screening Instrument (MNSI). The original questionnaire was extended with questions on autonomic ...

Disturbed information processing observed in neuropsychiatric disorders is reflected by deficient sensorimotor gating, measured as prepulse inhibition (PPI) of the acoustic startle response (ASR). Long-term, higher dose methamphetamine (METH) abuse patterns are associated with cognitive impairments, mania and/or schizophrenia-like psychosis. The present ...

Stress is known to affect sensorimotor gating (measured with prepulse inhibition of startle, or PPI), possibly improving perception of threat signals at the expense of other input during states of arousal. Stress also induces a variety of autonomic nervous system and endocrine responses, such as an activation of the hypothalamic-pituitary-adrenal axis. The ...

Nurr1 (NR4A2) is an orphan nuclear receptor highly essential for the dopaminergic development and survival. Altered expression of Nurr1 has been suggested as a potential genetic risk factor for dopamine-related brain disorders, including schizophrenia. In support of this, recent experimental work in genetically modified mice shows that mice with a heterozygous constitutive deletion of Nurr1 show a ...

Prepulse inhibition (PPI) of startle is an experimentally tractable measure of sensorimotor gating that can be readily evaluated in mice, rats, monkeys, and humans. PPI is the inhibitory effect of a low-intensity stimulus, the prepulse, on the startle response to a subsequent high-intensity stimulus. PPI has garnered great interest as a marker of ...

Nonassociative learning is a basic neuroadaptive behavior exhibited across animal phyla and sensory modalities but its role in brain intelligence is unclear. Current literature on habituation and sensitization, the classic "dual process" of nonassociative learning, gives highly incongruous accounts between varying experimental paradigms. Here we propose a general theory of nonassociative learning ...

The receptors in the cervical spine have important connections to the vestibular and visual apparatus as well as several areas of the central nervous system. Dysfunction of the cervical receptors in neck disorders can alter afferent input subsequently changing the integration, timing and tuning of sensorimotor control. Measurable changes in cervical joint position sense, eye ...

Postnatal hypofunction of N-methyl-D-aspartate (NMDA) receptors leads to several behavioral deficits in adult rats resembling deficits typical of schizophrenia-like deficits of sensorimotor gating. Thus far, it is not known whether the above disruptions are sensitive to neuroleptic drugs. In order to verify the above model in pharmacological terms, we ...

RationaleRat strains differ in sensitivity to the disruptive effects of dopamine agonists on sensorimotor gating, measured by prepulse inhibition (PPI) of startle. For example, Sprague Dawley (SD) rats are more sensitive to PPI-disruptive effects of apomorphine (APO) compared to Long Evans (LE) rats; F1 (SD � LE) and N2 generations exhibit intermediate ...

Gilles de la Tourette syndrome (GTS) is characterized by multiple fluctuating motor and vocal tics. These tics are often preceded by premonitory phenomena including the urge to move, or by exaggerated bodily sensations that can lead to considerable disability and difficulties with attention and concentration. In the past the premonitory phenomena were interpreted as the driving force behind tics. ...

Sensory gating, indexed by P50 suppression, and sensorimotor gating, indexed by prepulse inhibition (PPI), are impaired in schizophrenia spectrum disorders. There is considerable evidence that schizophrenia patients treated with atypical antipsychotics exhibit relatively less gating deficits than do other patients ...

Sensorimotor gating disruptions are seen in various psychiatric illnesses with putatively different pathologies, including schizophrenia and bipolar disorder. Interestingly, mice lacking the dopamine (DA) transporter (DAT) gene display markedly increased levels of DA, deficits in sensorimotor gating, and ...

In a large-scale meta-analysis, it has been recently shown that the transcription factor 4 (TCF4) gene is among the most prominent susceptibility genes for schizophrenia. Moreover, transgenic mice overexpressing TCF4 in the brain display a reduction of sensorimotor gating measured by prepulse inhibition (PPI) of the acoustic startle response (ASR). PPI is ...

An imbalance between different neurotransmitter systems is involved in the pathophysiological processes underlying schizophrenia. Since the neurotensin (NT) system modulates the activity of several of these neurotransmitters, drugs acting upon the NT system may act as novel antipsychotic drugs. This hypothesis is supported by studies with NT in animal models. For example, intracranial injection of ...

the trigeminal nuclei to the facial nucleus (Figure 2) [24,25].Threesuchpathways involvethalamic nuclei feedback from sensory cortex could gate the input of trigeminal sensory information to motor cortex are faithfully represented in the trigeminal nucleus [64,65]. However, cortical cells do not to follow inputs

Synapsin II is a synaptic vesicle-associated phosphoprotein that has been implicated in the pathophysiology of schizophrenia. Studies have demonstrated reductions in synapsin II mRNA and protein in medial prefrontal cortical post-mortem samples from patients with schizophrenia, genetic associations between synapsin II and schizophrenia, and synapsin II protein regulation by dopamine receptor ...

Maternal infection during pregnancy with a wide range of RNA and DNA viruses is associated with increased risk for schizophrenia and autism in their offspring. A common feature in these exposures is that virus replication induces innate immunity through interaction with Toll-like receptors (TLRs). We employed a mouse model wherein pregnant mice were exposed to polyinosinic-polycytidylic acid ...

Maternal infection during pregnancy with a wide range of RNA and DNA viruses is associated with increased risk for schizophrenia and autism in their offspring. A common feature in these exposures is that virus replication induces innate immunity through interaction with Toll-like receptors (TLRs). We employed a mouse model wherein pregnant mice were exposed to polyinosinic-polycytidylic acid ...

Isolation-reared (IR) rats exhibit various cognitive and behavioral abnormalities in adulthood of which locomotor hyperactivity and impaired prepulse inhibition (PPI) of an acoustic startle reflex are the two cardinal characteristics. Using an amended social deprivation-resocialization paradigm, the present study examined the role of the developmental specificity of the ...

BackgroundAdult animals with a neonatal ventral hippocampal lesion (NVHL) exhibit deficits in working memory and sensorimotor gating similar to those observed in schizophrenia. As cognitive deficits in this disorder are typically associated with changes in cortical metabolic levels, we investigated here whether an NVHL affects metabolic responses to ...

N-methyl-D-aspartate (NMDA)/glutamate receptor antagonists, such as phencyclidine (PCP), induce behavioral abnormalities (locomotor hyperactivity, sensorimotor gating deficits, impairments of cognition) in animals that are thought to model aspects of schizophrenia. The administration of PCP increases noradrenaline transmission in the ...

BackgroundGlycogen synthase kinase-3 (GSK-3) is a widely expressed and highly conserved serine/threonine protein kinase encoded by two genes that generate two related proteins: GSK-3? and GSK-3?. Mice lacking a functional GSK-3? gene were engineered in our laboratory; they are viable and display insulin sensitivity. In this study, we have characterized brain functions of GSK-3? KO mice by using a ...

An atrial septal aneurysm (ASA) is an uncommon cardiac abnormality. Clinical manifestation of this abnormality remains unclear: some authors have suggested an association between ASA and arrhythmias or between ASA and cerebral ischaemia. A major role in the diagnosis of ASA to date has been played by transoesophageal echocardiography and transthoracic ...

A large percentage of patients with schizophrenia are characterized by an abnormality in P50 sensory gating. This abnormality has been shown to be genetically linked to the alpha-7 nicotinic receptor and is transiently reversed by acute nicotine administration. These observations have led to the development of pharmacological ...

The ratio of magnetoencephalogram-recorded brain responses occurring 50ms after paired clicks (S2-evoked M50/S1-evoked M50) serves as a measure of sensory gating. An abnormally large ratio is commonly found in schizophrenia. Whether this abnormality indicates impaired gating is debated. Using event-related ...

Sensory and sensorimotor gating deficits characterize both Tourette syndrome (TS) and schizophrenia. Premonitory urges (PU) in TS can be assessed with the University of Sao Paulo Sensory Phenomena Scale (USP-SPS) and the Premonitory Urge for Tics Scale (PUTS). In 40 subjects (TS: n = 18; healthy comparison subjects [HCS]: n = 22), we examined the ...

For some time, dystonia has been seen as purely a motor disorder. Relatively novel concepts published approximately 10 years ago also presumed that in the development of dystonic dyskinesias, only motor behaviour was abnormal. Neurophysiological observations of various types of dystonic disorders, which were performed using sophisticated electromyography, polymyography, ...

Auditory P50/M50 paired-click studies have established an association between schizophrenia and impaired sensory gating in the auditory modality. However, the presumed cross-modal generality of the gating deficit has received little study. The present study examined gating in area 3b of primary somatosensory cortex to evaluate ...

The human spinal cord contains segregated sensory and motor pathways that have been difficult to quantify using conventional magnetic resonance imaging (MRI) techniques. Multiple sclerosis is characterized by both focal and spatially diffuse spinal cord lesions with heterogeneous pathologies that have limited attempts at linking MRI and behaviour. We used a novel magnetization-transfer-weighted ...

No currently used diagnostic test is an accurate predictor of patients who will develop morbidity or mortality from cardiac contusion. In a prospective study we used gated cardiac radionuclide angiography to assess cardiac function in 30 patients with blunt chest trauma, and we compared the results of this test with those of other diagnostic studies for cardiac contusion to ...

The serotonin-2A receptor (5-HT(2A)R) has been implicated in the pathogenesis of schizophrenia and related inhibitory gating and behavioral inhibition deficits of schizophrenia patients. The hallucinogen psilocybin disrupts automatic forms of sensorimotor gating and response inhibition in humans, but it is unclear so far whether the ...

BackgroundThe neural substrates regulating sensorimotor gating in rodents are studied in order to understand the basis for gating deficits in clinical disorders such as schizophrenia. N-methyl-d-aspartate (NMDA) infusion into the ventral temporal lobe, including caudal parts of the ventral hippocampal region and amygdala, has been ...

In order to develop a model of persistent sensorimotor gating that did not require acute NMDA (N-methyl-D-aspartate) receptor blockade, adult female Sprague-Dawley rats were pre-treated with N-methyl-scopolamine (1 mg/kg s.c.), then administered MK-801 (dizocilpine, 5 mg/kg i.p.) along with two separate doses (5 mg/kg) of pilocarpine. The drug regimen was ...

While much is known about receptor affinity profiles of antipsychotic medications, less is known about their impact on functional brain systems in patients with schizophrenia. We conducted functional magnetic resonance imaging (fMRI) studies with first-episode schizophrenia patients as they made saccades to unpredictable visual targets before and after 4-6 weeks of antipsychotic treatment. Matched ...

Early-onset schizophrenia appears to be clinically more severe than the adult-onset form of the disease. In a previous study, we showed that anatomically related grey and white matter abnormalities found in adolescents patients were larger and more widespread than what had been reported in the literature on adult schizophrenia. Particularly, we found novel structural ...

AbstractObjectiveThis article reviews the available scientific literature concerning the neurobiological substrates of Tourette's disorder (TD).MethodsThe electronic databases of PubMed, ScienceDirect, and PsycINFO were searched for relevant studies using relevant search terms.ResultsNeuropathological as well as structural and functional neuroimaging studies of TD implicate not only the ...

Seven adult patients with congenital lumbosacral lesions and clinical onset in adult life are reported. All also had an abnormally low and tethered spinal cord. A thickened filum terminale and a spinal lipoma are the most common lesions in adults, whereas others, including diastematomyelia, fibrous adhesions, previous meningocele repair and dermal sinus are more rare. Although ...

INTRODUCTION. Prepulse inhibition (PPI) of startle is an operational measure of the pre-attentive filtering process known as sensorimotor gating. PPI occurs when a relatively weak sensory event (the prepulse) is presented 30-500 ms before a strong startle inducing stimulus, and reduces the magnitude of the startle response. This experimental paradigm has ...

Prepulse inhibition (PPI) is a phenomenon in which a mild stimulus attenuates a cross-modality startle response to later intense stimulation. PPI is thought to index the central inhibitory mechanism through which behavioural responses are filtered. The present study compared the effects of two stress paradigms on the acoustic startle response (ASR) and on PPI in a rat model. The tail-pinch (TP) ...

Prepulse inhibition (PPI) of the startle response serves to prevent the interruption of ongoing perceptual and early sensory analysis and provides a simple operational measure of sensorimotor gating. In line with postulated deficits in early stages of information processing, PPI is disrupted in schizophrenia. PPI is considered a valid candidate for an ...

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) may be biosynthesized from a precursor ?-linolenic acid (LNA) or obtained preformed in the diet. Dams were fed four diets with different levels of the various n-3 fatty acids during pregnancy and lactation, and their offspring were weaned to the same diets: �n-3 Deficient�, containing (as % total fatty acids) 0.07% of LNA; �Low ...

A high incidence of seizures occurs during the neonatal period when immature networks are hyperexcitable and susceptible to hypersyncrhonous activity. During development, ?-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in adults, typically excites neurons due to high expression of the Na(+)-K(+)-2Cl(-) cotransporter (NKCC1). NKCC1 facilitates seizures because it renders GABA ...

The cholinergic basis of auditory "gating" in the sensorimotor nucleus HVc and its efferent target robustus archistriatalis (RA) was investigated in anesthetized zebra finches. Injections of cholinergic agonists carbachol or muscarine into HVc strongly affected discharge rates and diminished auditory responsiveness in both HVc and its target RA, changes ...

N-desmethylclozapine (NDMC), one of the major metabolites of clozapine, has been demonstrated to exhibit partial agonistic activity at M(1) muscarinic receptors in vitro. Behavioral effects of NDMC were examined to determine whether NDMC contributed to the antipsychotic effects of clozapine via activation of muscarinic receptors. Both NDMC (10-30mg/kg) and its parent compound clozapine (3-10mg/kg) ...

Oscillatory activity in the ?-band (15-30 Hz) has been studied in detail in the sensorimotor cortex. It has been postulated that ?-activity acts as a localized gating of cortical activity. Here, the induced oscillatory response in the ?-band is measured by magnetoencephalography, and the hemodynamic response is measured by fMRI. We assess the linearity of ...

Professional musicians are an excellent human model of long term effects of skilled motor training on the structure and function of the motor system. However, such effects are accompanied by an increased risk of developing motor abnormalities, in particular musician's dystonia. Previously we found that there was an expanded spatial integration of proprioceptive input into the ...

Power consumption regularities of the most perspective quasi-adiabatic base logic gates are investigated by method of computer modeling. The effect of abnormal high power consumption in a range of low frequencies is discovered and explained; the method of its neutralization is offered. It is revealed, that in a range of high frequencies energy dissipation ...

Gated cardiac magnetic resonance (MR) images were obtained in two normal volunteers and 21 adults with a variety of cardiovascular abnormalities. The images were correlated with data from clinical examination, electrocardiograms, and cardiac catheterization. Gated cardiac images were superior to nongated images. Combined cardiac and ...

The psychotomimetic drug D-amphetamine (AMPH), disrupts prepulse inhibition (PPI) of the startle response, an operational measure of sensorimotor gating that is deficient in schizophrenia patients. Historically, this effect has been attributed to dopaminergic substrates; however, AMPH also increases norepinephrine (NE) levels, and enhancement of central NE ...

The psychotomimetic drug d-amphetamine (AMPH), disrupts prepulse inhibition of the startle response (PPI), an operational measure of sensorimotor gating that is deficient in schizophrenia patients. Historically, this effect has been attributed to dopaminergic substrates; however, AMPH also increases norepinephrine (NE) levels, and enhancement of central NE ...

Neuregulin-1 (Nrg1)/erbB signaling regulates neuronal development, migration, myelination, and synaptic maintenance. The Nrg1 gene is a schizophrenia susceptibility gene. To understand the contribution of Nrg1 signaling to adult brain structure and behaviors, we have studied the regulation of Type III Nrg1 expression and evaluated the effect of decreased expression of the Type III Nrg1 isoforms. ...

Perinatal exposure to testosterone (T), which can act upon both the androgen receptor (AR) and, via aromatization of T into estrogens, upon estrogen receptors, organizes many adult behaviors in rodents. We compared behaviors in wild-type (WT) male rats and AR-deficient rats with the testicular feminization mutation (Tfm), which on the day of birth were either gonadectomized (Neo-Gdx) or sham ...

Nurr1 (NR4A2) is an orphan nuclear receptor highly essential for the development and maintenance of dopaminergic neurons. Reduced expression of Nurr1 has been linked to the etiopathogenesis of Parkinson's disease and other dopamine-related disorders such as schizophrenia. Recent experimental work in mice with a heterozygous constitutive deletion of Nurr1 has revealed that this genetic manipulation ...

Dopamine-induced hyperactivity and deficient sensorimotor gating, measured as prepulse inhibition (PPI) of the acoustic startle response (ASR), are used as animal models for neuropsychiatric disorders such as schizophrenia and Tourette's syndrome. We here investigated whether excitotoxic lesions of the rat entopeduncular nucleus (EPN), the equivalent to ...

Prepulse inhibition (PPI) refers to the reduction in the startle response when a startling stimulus is preceded by a weak prestimulus, and is an endophenotype of deficient sensorimotor gating in several neuropsychiatric disorders. Emerging evidence suggests that norepinephrine (NE) regulates PPI, however, the circuitry involved is unknown. We found ...

Modeling juvenile traumatic brain injury (TBI) in rodents presents several unique challenges compared to adult TBI, one of which is selecting appropriate sensorimotor behavioral tasks that enable the assessment of the extent of injury and recovery over time in developing animals. To address this challenge, we performed a comparison of common sensorimotor ...

BackgroundThe psychotomimetics ketamine and MK-801, non-competitive NMDA receptor (NMDAr) antagonists, induce cognitive impairment and aggravate schizophrenia symptoms. In conscious rats, they produce an abnormal behavior associated with a peculiar brain state characterized by increased synchronization in ongoing ? (30�80 Hz) oscillations in the frontoparietal ...

Maternal smoking during pregnancy is associated with auditory processing deficits in children; these effects have been confirmed with animal models of continuous high-dose prenatal nicotine exposure. The present experiments utilized a novel, low-dose, intermittent, intravenous (IV) gestational nicotine exposure model to investigate potential deficits on the preattentive process of ...

Patients with writer's cramp (WC) show abnormalities of sensorimotor integration possibly contributing to their motor deficit. We studied sensorimotor integration by determining short-latency afferent inhibition (SAI) in 12 WC patients and 10 age-matched healthy controls. A conditioning electrical median nerve stimulus was followed 14 ...

The pathophysiology of dystonia has been best studied in patients with focal hand dystonia. A loss of inhibitory function has been demonstrated at spinal, brainstem and cortical levels. Many cortical circuits seem to be involved. One consequence of the loss of inhibition is a failure of surround inhibition, and this appears to directly lead to overflow and unwanted muscle spasms. There are mild ...

Dogs exposed to acrylamide develop a sensorimotor peripheral neuropathy and megaoesophagus. The presence of neuropathy was confirmed electrophysiologically and histologically. Hindlimb motor conduction velocity was reduced and there was a loss of large diameter myelinated fibres in the dorsal common digital nerve and the tibial nerve. The conduction velocity of vagal motor ...

A patient with infective endocarditis was evaluated by Ga-67 citrate imaging, Tc-99m pyrophosphate imaging, equilibrium gated blood pool imaging, and Tl-201 imaging of the chest. The diagnosis of ventricular abscess was first suggested by an abnormal gallium scan. At surgery, an abscess was identified in the area where the scan was ...

Twenty normal subjects and ten patients with pericardial abnormalities underwent ECG-gated magnetic resonance (MR) imaging of the thorax using a 0.35-tesla superconducting system. The patients with pericardial abnormalities were also evaluated with serial chest radiography, ultrasound, computed tomography, and/or angiography. ECG ...

ContextStudying sensorimotor and neurocognitive impairments in unaffected family members of individuals with autism may help identify familial pathophysiological mechanisms associated with the disorder.ObjectiveTo determine whether atypical sensorimotor or neurocognitive characteristics associated with autism are present in first-degree relatives of ...

BackgroundTiming abilities are critical to the successful management of everyday activities and personal safety, and timing abnormalities have been argued to be fundamental to impulsiveness, a core symptom of attention-deficit/hyperactivity disorder (ADHD). Despite substantial evidence of timing deficits in ADHD youth, only two studies have explicitly examined timing in ADHD ...

Although schizophrenia clusters in families, it is not inherited in Mendelian fashion. This suggests that there may be alternative phenotypic expressions of genes that convey risk for schizophrenia, such as more elementary physiological or biochemical defects. One proposed phenotype is impaired inhibitory gating of the auditory evoked potential to repeated stimuli. Normally, ...

Neurophysiological studies have provided evidence of primary motor cortex hyperexcitability in primary dystonia, but several functional imaging studies suggest otherwise. To address this issue, we measured sensorimotor activation at both the regional and network levels in carriers of the DYT1 dystonia mutation and in control subjects. We used (15)Oxygen-labelled water and ...

Neurophysiological studies have provided evidence of primary motor cortex hyperexcitability in primary dystonia, but several functional imaging studies suggest otherwise. To address this issue, we measured sensorimotor activation at both the regional and network levels in carriers of the DYT1 dystonia mutation and in control subjects. We used ...

Both an EEG P50 sensory gating deficit and abnormalities of the temporal lobe structure are considered characteristic of schizophrenia. The standard P50 sensory gating measure does not foster differential assessment of left- and right-hemisphere contributions, but its analogous MEG M50 component may be used to measure ...

We have developed a method by which any two sets of R-wave-synchronized radionuclide images may be registered, color-coded, and displayed in cinematic fashion so that the image sets are superimposed and shown simultaneously in contrasting colors. The technique has been applied to technetium-99m stannous pyrophosphate (Tc-99m PPi) and equilibrium blood-pool images. Gated Tc-99m ...

The authors present a case of a 56-year-old man with altered mental status. Magnetic resonance imaging (MRI) of the brain revealed non-enhancing abnormalities on T2 and FLAIR imaging in the brainstem, cerebellum, and cerebrum. Immunohistochemisty demonstrated precursor T-cell lymphoblastic lymphoma. After treatment with methotrexate, he improved clinically without focal ...

Autism spectrum disorder (ASD) often involves sensory and motor problems, yet the proprioceptive sense of limb position has not been directly assessed. We used three tasks to assess proprioception in adolescents with ASD who had motor and sensory perceptual abnormalities, and compared them to age- and IQ-matched controls. Results showed no group differences in proprioceptive ...

The kinematic properties of upper limb trajectories of simple reaching movements have been analysed in patients with idiopathic torsion dystonia (ITD). The velocity profiles differed from those of neurologically healthy subjects by being less symmetric. In several patients movement execution was slow due to a longer deceleration time. This phenomenon was even more conspicuous in the absence of ...

BackgroundSensorimotor gating, as measured by prepulse inhibition of the startle reflex, is deficient in schizophrenia patients, and in rats after specific manipulations of limbic cortico�striato�pallido�thalamic circuitry. For example, prepulse inhibition in rats is disrupted after D1 blockade in the medial prefrontal cortex, and after ...

Electrical stimulation of the digital nerves of the index finger produces changes in the EMG signal during steady voluntary contraction of the first dorsal interosseous muscle. This electrocutaneous reflex (ECR) was studied in 90 patients classified into different categories according to diagnostic criteria for multiple sclerosis. In addition, pattern reversal visual evoked responses (VER), ...

Cerebral palsy (CP) is a complex disorder of locomotion, posture and movements resulting from pre-, peri- or postnatal damage to the developing brain. In a previous study (Strata, F., Coq, J.O., Byl, N.N., Merzenich, M.M., 2004. Comparison between sensorimotor restriction and anoxia on gait and motor cortex organization: implications for a rodent model of cerebral palsy. ...

Deficits in sensorimotor gating as assessed by prepulse inhibition (PPI) of the startle reflex have been reported in schizophrenia. However, the state or trait nature of these deficits and the relationships with clinical features and psychopathological symptoms are not clear. To explore these issues, we performed a longitudinal study with schizophrenia ...