ABSTRACT
OBJECTIVE: Wireless implantable brain machine interfaces (BMIs) are a promising tool to restore communication and motor functions for individuals with severe motor disability. Prior to clinical application, recording performance must be sufficiently confirmed by animal experiments. In this paper, we aimed to evaluate the performance of a novel BMI wireless device for recording brain activity in two nonhuman primates. METHOD: We customized a wireless device for implantable BMIs for clinical application. We used a battery instead of a wireless power charging system. Thirty-two electrodes were subdurally implanted over the left temporoparietal cortex. We evaluated the recording performance of the wireless device by auditory steady-state responses (ASSRs) and ketamine-induced responses. RESULT: The devices successfully recorded broadband oscillatory activities up to the high-frequency band from the temporal cortex in two awake macaque monkeys. Spectral analysis of raw signals demonstrated that the devices detected characteristic results of a 40-Hz ASSR and prominent high-frequency band activity induced by ketamine injection. CONCLUSION: We confirmed the functionality of the wireless device in recording and transmitting electrocorticography (ECoG) signals with both millisecond precision and recording stability. SIGNIFICANCE: These results provide confidence that this wireless device can be a translational tool for other fundamental neuroscientific studies in free-moving models.
Subject(s)
Disabled Persons , Ketamine , Motor Disorders , Animals , Humans , Electrocorticography , Body Mass Index , Ketamine/pharmacology , Wakefulness , MacacaABSTRACT
Glycine 165, which is located near the active site metal, is mostly conserved in aligned amino acid sequences of manganese-containing superoxide dismutase (Mn-SOD) proteins, but is substituted to threonine in most iron-containing SODs (Fe-SODs). Because threonine 165 is located between Trp128 and Trp130, and Trp128 is one of the metal-surrounding aromatic amino acids, the conversion of this amino acid may affect the metal-specific activity of Escherichia coli Mn-SOD. In order to clarify this possibility, we prepared a mutant of E. coli Mn-SOD with the replacement of Gly165 by Thr. The ratio of the specific activities of Mn- to Fe-reconstituted enzyme increased from 0.006 in the wild-type to 0.044 in the mutant SOD; therefore, the metal-specific SOD was converted to a metal-tolerant SOD. The visible absorption spectra of the Fe- and Mn-reconstituted mutant SODs indicated the loss of Mn-SOD character. It was concluded that Gly at position 165 plays a catalytic role in maintaining the integrity of the metal specificity of Mn-SOD.
Subject(s)
Escherichia coli/enzymology , Glycine/genetics , Manganese/metabolism , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism , Threonine/genetics , Catalysis , Catalytic Domain , Crystallography, X-Ray , Escherichia coli/genetics , Glycine/chemistry , Glycine/metabolism , Mutagenesis, Site-Directed , Mutation/genetics , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Superoxide Dismutase/chemistry , Threonine/chemistry , Threonine/metabolismABSTRACT
BACKGROUND: (CRPS I [formerly called reflex sympathetic dystrophy]) is a syndrome with pain and signs of autonomic dysfunction after trauma or immobilization; the pathophysiologic mechanisms of CRPS I, however, remain unknown. DESIGN: The authors present a case of CRPS I associated with amyotrophic lateral sclerosis. Along with the motor paresis due to amyotrophic lateral sclerosis, pain, swelling, and signs of autonomic disturbance occurred. CONCLUSIONS: This case supports the hypothesis that immobilization is one of the major contributing factors for CRPS I.
