ABSTRACT
In contrast to traditional representational perspectives in which the motor cortex is involved in motor control via neuronal preference for kinetics and kinematics, a dynamical system perspective emerging in the last decade views the motor cortex as a dynamical machine that generates motor commands by autonomous temporal evolution. In this review, we first look back at the history of the representational and dynamical perspectives and discuss their explanatory power and controversy from both empirical and computational points of view. Here, we aim to reconcile the above perspectives, and evaluate their theoretical impact, future direction, and potential applications in brain-machine interfaces.
Subject(s)
Biomechanical Phenomena , Brain-Computer Interfaces , Motor Cortex/physiology , Neurons/physiologyABSTRACT
Objective To explore the feasibility and application in quantifying the rabbit central nervous system by using magnetic resonance diffusion tensor imaging(DTI)sequences.Methods 12 normal New Zealand rabbits were used to scan the brain and spinal cord of rabbits by DTI sequence of 1.5T MR machine,and the normal apparent diffusion coefficient(ADC)and fractional anisotropy (FA)values were obtained in the different regions of the brain and every spinal segment of rabbits,to analyse the characteristics and regularity of numerical changes.Results The average ADC value in the brain of rabbits was (0.87±0.08)×10-3mm2/s,the average FA value was 0.23±0.09;the average ADC value in cervical spinal cord was (1.05±0.14)×10-3mm2/s,the average FA value was 0.55±0.08.The average ADC value in thoracic spinal cord was (1.14±0.12)×10-3mm2/s,and the average FA value was 0.57±0.06;the average ADC value in lumber spinal cord was (1.20±0.12)×10-3mm2/s,and the average FA value was 0.61±0.06.Conclusion FA average value in the brain is lower than that in spinal cord (P<0.001),the difference is related to the distribution of nerve fibers and physiological curvature of spine.ADC average value in the brain is lower than that in spinal cord(P<0.001),this is related to the volume of spinal canal and the peripheral structure of spinal cord.The difference of FA value in the brain and spinal cord is higher than ADC value.
ABSTRACT
ObjectiveTo study the relationship between the susceptibility of mutiple sclerosis (MS) and single nucleotide polymorphisms (SNP) rs6897932 of interleukin-7 receptor alpha (IL-7RA) in Asian.MethodsThe SNP rs6897932 in the IL-7RA gene was genotyped by real time polymerase chain reaction (PCR) using TaqMan SNP Genotyping Assays. 78 cases with MS and neuromyelitis optica (NMO), 187 patients with non-NMO MS and 158 healthy controls were enrolled.ResultsThe frequencies of both the C allele and the CC genotype of SNP rs6897932 in the IL-7RA gene in non-NMO MS patients were higher than those of healthy controls(89.3％ vs. 79.8％, OR=2.12, 95％CI:1.38-3.25 P＜0.01; 78.6％ vs. 63.3％, OR=2.13,95％CI:1.32-3.43, P＜0.01).However, there was no significant difference in the frequency of either the C allele or the CC genotype between control group and NMO patients.ConclusionsIL-7RA gene is one of susceptibility gene for MS in Asian. C allele was presumed as a risk factor of MS while T allele might be a protective factor.
ABSTRACT
Objective To investigate the genetic association of MTHFRC677T between CBS844ins68 polymorphism and young ischemic stroke.Methods The polymorphism of MTHFRC677T and CBS844ins68 in 98 stroke patients and 116 control subjects were examined and analyzed by using PCR-RFLP.Results The frequencies of two alleles were as follows: T allele 54.09%,C allele 45.91% in patients and T 37.93%,C 62.07% in controls(?2=11.18,P