Acetylcholine esterase activity and behavioral response in hypoxia induced neonatal rats: effect of glucose, oxygen and epinephrine supplementation

Brain damage due to an episode of hypoxia remains a major problem in infants causing deficit in motor and sensory function. Hypoxia leads to neuronal functional failure, cerebral palsy and neuro-developmental delay with characteristic biochemical and molecular alterations resulting in permanent or transitory neurological sequelae or even death. During neonatal hypoxia, traditional resuscitation practices include the routine administration of 100% oxygen, epinephrine and glucose. In the present study, we assessed the changes in the cholinergic system by measuring the acetylcholinesterase (AChE) activity and the behavioral responses shown by hypoxia induced neonatal rats and hypoxic rats supplemented with glucose, oxygen and epinephrine using elevated plus-maze and open-field test. The acetylcholine esterase enzyme activity showed a significant decrease in cerebral cortex, whereas it increased significantly in the muscle of experimental rats when compared to control. Hypoxic rats supplemented with glucose, glucose and oxygen showed a reversal to the control status. Behavioral studies were carried out in experimental rats with elevated plus-maze test and open-field test. Hypolocomotion and anxiogenic behavioral responses were observed in all experimental rats when compared to control, hypoxic rats supplemented with glucose, glucose and oxygen. Thus, our results suggest that brain damage due to hypoxia, oxygen and epinephrine supplementation in the neonatal rats cause acetylcholine-neuromuscular-defect leading to hypolocomotion and anxiogenic behavioral response. Glucose and glucose with oxygen supplementation to hypoxic neonates protect the brain damage for a better functional status in the later life.     

Atypical cerebral lateralisation in adults with compensated developmental dyslexia demonstrated using functional transcranial Doppler ultrasound

Functional transcranial Doppler ultrasound (fTCD) is a relatively new and non-invasive technique that assesses cerebral lateralisation through measurements of blood flow velocity in the middle cerebral arteries. In this study fTCD was used to compare functional asymmetry during a word generation task between a group of 30 dyslexic adults and a group of 30 non-dyslexic individuals. In light of previous evidence of atypical laterality in dyslexia, a reduced leftward asymmetry was predicted and confirmed. We know from previous research that most people with atypical language lateralisation have normal language and literacy skills: nevertheless, our results confirm that language laterality is reduced in those with dyslexia. Theoretical explanations for this apparent conundrum are discussed.     

Rapid cerebral hemodynamic modulation during set shifting: Evidence of time-locked associations with cognitive control in females

Set shifting provokes specific alterations of cerebral hemodynamics in basal cerebral arteries. However, no gender differences have been reported. In the following functional transcranial Doppler study, we introduced cerebral hemodynamic modulation to the aspects of set shifting during Wisconsin Card Sorting Test (WCST). Twenty-one subjects underwent the WCST during insonation of the middle cerebral arteries. We examined gender effects on task performance and cerebral hemodynamic modulation. Further, we investigated the linkage between performance and cerebral hemodynamic modulation. In females, maximum positive modulation was restricted to the behaviorally relevant time point of set shifting, and there were time-locked associations between mental slowing during set shifting and rapid cerebral hemodynamic modulation exclusively in females. This study provides evidence of gender-related cerebral hemodynamic modulation during set shifting, and we detected time-locked brain–behavior relationship during cognitive control in females.     

Sensory processing disorders in children with cerebral palsy

ObjectiveTo evaluate sensory processing in children with CP using the Sensory Profile questionnaire and to compare results with the ones of children with typical development (TD).MethodsWe assessed sensory processing of 59 TD children and 43 CP children using the Sensory Profile, a standardized parent reporting measure that records children's responses to sensory events in daily life. Mann-Whitney test was used to compare the results of sensory processing evaluation among the groups. Bonferroni correction was applied.ResultsWe found differences in sensory processing between groups in 16 out of the 23 categories evaluated in the Sensory Profile.ConclusionOur results pointed out to the existence of disturbances in the processing of sensory information in CP. Based on the importance of the sensory integration process for motor function, the presence of such important disturbances draw the attention to the implementation of sensory therapies which improve function in these children.     

基底神经节损伤对知觉性启动效应影响的进一步研究

基底神经节的认知和记忆功能是近年认知神经科学研究的热点。该研究采用两项语义性启动效应（自由联想、偏好）和一项知觉性启动效应（字辨认）任务,发现基底神经节损伤、分别伴两侧海马或右侧丘脑损伤的两例患者的语义性启动效应正常,知觉性启动效应障碍。由于先前研究已经证实海马或丘脑结构与启动效应无关,因此该两例患者表现的知觉性启动效应障碍可归因于基底神经节损伤,进一步证实了王常生等人认为基底神经节可能具有或参与知觉性启动效应调节作用,与语义性启动效应无关的观点。     

Perseverative Thinking and Health: Neurovisceral Concomitants

In the present paper we present the outlines of a model that may help to guide us in our understanding of the relationship between perseverative thinking and health. We will emphasize the relationship between perseverative thinking and vagal cardiac control and propose a group of underlying neural structures that serve to integrate these functions in the service of self-regulation and adaptability of the organism. We will attempt to place this network in the context of systems models which involve feedback and feedforward circuits with special attention to negative feedback mechanisms and inhibitory processes. From a systems perspective, inhibitory processes can be viewed as negative feedback circuits that allow for the interruption of ongoing behavior and the re-deployment of resources to other tasks. When these negative feedback mechanisms are compromised, positive feedback loops may develop as a result of dis-inhibition. From this perspective, the relative sympathetic activation seen in perseverative thinking may represent dis-inhibition due to faulty inhibitory mechanisms.     

高频超声对膝关节病变的观察

通过超声对髌上囊、股骨髁间软骨情况、胭窝滑囊、髌腱等膝部结构的观察,评价超声对膝关节病变的辅助诊断、观察疗效的价值。通过高频超声对膝关节肿胀、疼痛病例纽与对照组、病例组治疗前后髌上囊液体、滑膜、股骨髁间软骨、胭窝滑囊积液情况以及髌腱厚度及回声进行对比观察。病例组髌上囊液体及滑膜增厚,股骨髁间软骨多有不同程度改变,胭窝滑...     

A brief review on the use of functional near-infrared spectroscopy (fNIRS) for language imaging studies in human newborns and adults

Upon stimulation, real time maps of cortical hemodynamic responses can be obtained by non-invasive functional near-infrared spectroscopy (fNIRS) which measures changes in oxygenated and deoxygenated hemoglobin after positioning multiple sources and detectors over the human scalp. The current commercially available transportable fNIRS systems have a time resolution of 1-10 Hz, a depth sensitivity of about 1.5 cm, and a spatial resolution of about 1 cm. The goal of this brief review is to report infants, children and adults fNIRS language studies. Since 1998, 60 studies have been published on cortical activation in the brain’s classic language areas in children/adults as well as newborns using fNIRS instrumentations of different complexity. In addition, the basic principles of fNIRS including features, strengths, advantages, and limitations are summarized in terms that can be understood even by non specialists. Future prospects of fNIRS in the field of language processing imaging are highlighted.     

Neurophysiology and neuroanatomy of smooth pursuit: Lesion studies

Smooth pursuit impairment is recognized clinically by the presence of saccadic tracking of a small object and quantified by reduction in pursuit gain, the ratio of smooth eye movement velocity to the velocity of a foveal target. Correlation of the site of brain lesions, identified by imaging or neuropathological examination, with defective smooth pursuit determines brain structures that are necessary for smooth pursuit. Paretic, low gain, pursuit occurs toward the side of lesions at the junction of the parietal, occipital and temporal lobes (area V5), the frontal eye field and their subcortical projections, including the posterior limb of the internal capsule, the midbrain and the basal pontine nuclei. Paresis of ipsiversive pursuit also results from damage to the ventral paraflocculus and caudal vermis of the cerebellum. Paresis of contraversive pursuit is a feature of damage to the lateral medulla. Retinotopic pursuit paresis consists of low gain pursuit in the visual hemifield contralateral to damage to the optic radiation, striate cortex or area V5. Craniotopic paresis of smooth pursuit consists of impaired smooth eye movement generation contralateral to the orbital midposition after acute unilateral frontal or parietal lobe damage. Omnidirectional saccadic pursuit is a most sensitive sign of bilateral or diffuse cerebral, cerebellar or brainstem disease. The anatomical and physiological bases of defective smooth pursuit are discussed here in the context of the effects of lesion in the human brain.     

Neocortical maturation during adolescence: change in neuronal soma dimension

During adolescence, cognitive abilities increase robustly. To search for possible related structural alterations of the cerebral cortex, we measured neuronal soma dimension (NSD = width times height), cortical thickness and neuronal densities in different types of neocortex in post-mortem brains of five 12-16 and five 17-24 year-olds (each 2F, 3M). Using a generalized mixed model analysis, mean normalized NSD comparing the age groups shows layer-specific change for layer 2 (p < .0001) and age-related differences between categorized type of cortex: primary/primary association cortex (BA 1, 3, 4, and 44) shows a generalized increase; higher-order regions (BA 9, 21, 39, and 45) also show increase in layers 2 and 5 but decrease in layers 3, 4, and 6 while limbic/orbital cortex (BA 23, 24, and 47) undergoes minor decrease (BA 1, 3, 4, and 44 vs. BA 9, 21, 39, and 45: p = .036 and BA 1, 3, 4, and 44 vs. BA 23, 24, and 47: p = .004). These data imply the operation of cortical layer- and type-specific processes of growth and regression adding new evidence that the human brain matures during adolescence not only functionally but also structurally.