Improved long-term recording of nerve signal by modified intrafascicular electrodes in rabbits

Microsurgery ◽  
2008 ◽  
Vol 28 (3) ◽  
pp. 173-178 ◽  
Author(s):  
Xiaofeng Jia ◽  
Gehua Zhen ◽  
Adrian Puttgen ◽  
Jian Zhang ◽  
Tongyi Chen
Keyword(s):  
Nerve Signal ◽  
Intrafascicular Electrodes

scholarly journals Wire Electrodes Embedded in Artificial Conduit for Long-term Monitoring of the Peripheral Nerve Signal

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 184 ◽  
Author(s):  
Woohyun Jung ◽  
Sunyoung Jung ◽  
Ockchul Kim ◽  
HyungDal Park ◽  
Wonsuk Choi ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Axon Regeneration ◽  
Scar Formation ◽  
Tissue Response ◽  
Nerve Signal ◽  
Long Term Monitoring ◽  
The Wire ◽  
Term Monitoring

Massive efforts to develop neural interfaces have been made for controlling prosthetic limbs according to the will of the patient, with the ultimate goal being long-term implantation. One of the major struggles is that the electrode’s performance degrades over time due to scar formation. Herein, we have developed peripheral nerve electrodes with a cone-shaped flexible artificial conduit capable of protecting wire electrodes from scar formation. The wire electrodes, which are composed of biocompatible alloy materials, were embedded in the conduit where the inside was filled with collagen to allow the damaged nerves to regenerate into the conduit and interface with the wire electrodes. After implanting the wire electrodes into the sciatic nerve of a rat, we successfully recorded the peripheral neural signals while providing mechanical stimulation. Remarkably, we observed the external stimuli-induced nerve signals at 19 weeks after implantation. This is possibly due to axon regeneration inside our platform. To verify the tissue response of our electrodes to the sciatic nerve, we performed immunohistochemistry (IHC) and observed axon regeneration without scar tissue forming inside the conduit. Thus, our strategy has proven that our neural interface can play a significant role in the long-term monitoring of the peripheral nerve signal.

Retrotrapezoid nucleus glutamate injections: long-term stimulation of phrenic activity

1994 ◽  
Vol 76 (2) ◽  
pp. 760-772 ◽  
Author(s):  
E. E. Nattie ◽  
A. Li
Keyword(s):  
Blood Pressure ◽  
Firing Rate ◽  
Single Unit ◽  
Respiratory Cycle ◽  
Cycle Duration ◽  
Retrotrapezoid Nucleus ◽  
Nerve Signal ◽  
Subsequent Response ◽  
Blood Pressure Responses

In chloralose-urethan anesthetized, paralyzed, vagotomized, glomectomized, and servo-ventilated cats we examined the effects of 10 nl of glutamate (10 mM, 100 mM, and 1 M) injected unilaterally over 60 s into the region of the retrotrapezoid nucleus (RTN). Seven 10 mM glutamate injections produced no consistent effects on the amplitude of the integrated phrenic nerve signal, respiratory cycle duration, or blood pressure. Ten 100 mM injections consistently increased integrated phrenic amplitude significantly from a baseline average of 31 +/- 2% (SE) of maximum to a peak response average of 50 +/- 3% of maximum. This effect was long lasting (45.6 +/- 8.6 min). Blood pressure responses were variable. Seven 1 M glutamate injections consistently decreased integrated phrenic amplitude significantly from a baseline average for all injections of 29 +/- 3% of maximum to a peak average of 20 +/- 5% of maximum. Respiratory cycle duration and blood pressure responses were variable. Prior injection into the RTN of 10 nl of 100 mM kynurenic acid attenuated the subsequent response of the integrated phrenic amplitude to injection of 10 nl of glutamate at the same site. Comparison of glutamate (10 nl, 100 mM) injected over 60 s vs. 30 ms showed that the prolonged increase in phrenic activity was related to the longer-duration (60-s) injections and that RTN single units were stimulated for up to 5 min on average after the 60-s injection with one unit showing an increase in firing rate over 40 min. After the 30-ms injection, integrated phrenic amplitude and RTN unit mean firing rate were increased for the first two breaths and at 5 min after the injection. We conclude that glutamate injected into the RTN increases local single-unit firing rate and the amplitude of the integrated phrenic activity. Injections made over 60 s result in prolonged phrenic stimulation and, in some cases, in RTN single-unit firing rate.

Long-term feasibility and biocompatibility of directly microsurgically implanted intrafascicular electrodes in free roaming rabbits

2018 ◽  
Vol 107 (2) ◽  
pp. 435-444 ◽  
Author(s):  
Gehua Zhen ◽  
Huanwen Chen ◽  
Shin-Yi Tsai ◽  
Jian Zhang ◽  
Tongyi Chen ◽  
...  
Keyword(s):  
Intrafascicular Electrodes

Long-term biocompatibility of implanted polymer-based intrafascicular electrodes

2002 ◽  
Vol 63 (5) ◽  
pp. 501-506 ◽  
Author(s):  
Stephen M. Lawrence ◽  
Jytte O. Larsen ◽  
Kenneth W. Horch ◽  
Ron Riso ◽  
Thomas Sinkjaer
Keyword(s):  
Intrafascicular Electrodes

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Brief summary of Kleť photographic search programme for minor planets

1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec
Keyword(s):  
Ccd Camera ◽  
Minor Planet ◽  
Minor Planets ◽  
Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

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