scholarly journals AFTER-POTENTIAL OF SPINAL AXONS IN VIVO

1953 ◽  
Vol 36 (5) ◽  
pp. 643-657 ◽  
Author(s):  
Donald O. Rudin ◽  
George Eisenman
Keyword(s):  
Spinal Cord ◽  
Peripheral Nerve ◽  
Dorsal Column ◽  
Half Time ◽  
Recovery Sequence ◽  
Recovery Curve ◽  
Myelinated Fibers ◽  
Afferent Volley

A method is evolved whereby the after-potential sequence intrinsic to longitudinal dorsal column myelinated fibers may be studied in isolation from those events occurring in intact spinal cord subjected to an afferent volley. The recovery sequence intrinsic to dorsal column fibers, after refractoriness is over, is characterized by supernormality approximately four to five times greater than that seen in peripheral nerve. This supemormality averages 15.7 ± 4 per cent (current calibration) at peak and decays exponentially with a half-time of 7.5 msecs. It is not followed by subnormality unless conditioning is repeated more than three times at frequencies greater than 100/sec. Characterization of the recovery curve of dorsal column fibers permits by exclusion, the allocation of the origin of DRV to structures more centrally located. DCV (the dorsal column counterpart of DRV) is seen to exist equally developed in active and passive dorsal column fibers.

Physiology of Spinal Cord, Nerve Root and Peripheral Nerve Compression

1956 ◽  
Vol 185 (1) ◽  
pp. 217-229 ◽  
Author(s):  
Samuel Gelfan ◽  
I. M. Tarlov
Keyword(s):  
Spinal Cord ◽  
Peripheral Nerve ◽  
Nerve Root ◽  
Peripheral Nerves ◽  
Compressive Force ◽  
Mechanical Deformation ◽  
Dorsal Column ◽  
Neuronal Structure ◽  
Mechanical Pressure ◽  
Wide Range

The reversible conduction block produced by maintained mechanical pressure around small segments of spinal cord, nerve root or peripheral nerve (dog) is due to mechanical deformation of the neuronal tissue and not to lack of O2. The compressed segment, although ischemic, is not anoxic; O2 from adjacent nonischemic tissue reaches it, presumably by diffusion. The entire pattern of modification of neuronal responses by compression and the postdecompression recovery pattern are distinctly different from the patterns observed during anoxia and recovery from the latter, indicating the difference in mechanisms by which mechanical deformation and O2 lack block conduction. The largest fibers in dorsal columns, roots and peripheral nerves are most susceptible to pressure and the smallest ones are relatively most resistant. Secondary neurons are less vulnerable than the primary afferent ones to light and moderate, but suprasystolic, circumferential spinal cord pressure. All components of the composite spinal cord potential are blocked at about the same time by larger compressive forces. Anoxia, on the other hand, always inactivates secondary neurons before dorsal column fibers and blocks smaller A fibers in peripheral nerves before the larger ones. The latency for complete blocking in each neuronal structure is specific and irreducible in the case of anoxia, whereas in compression it varies over a wide range, depending upon the magnitude of the compressive force.

scholarly journals In vivo characterization of microglial engulfment of dying neurons in the zebrafish spinal cord

2015 ◽  
Vol 9 ◽  
Author(s):  
Marco Morsch ◽  
Rowan Radford ◽  
Albert Lee ◽  
Emily K. Don ◽  
Andrew P. Badrock ◽  
...  
Keyword(s):  
Spinal Cord ◽  
In Vivo Characterization

In vivo characterization of colorectal and cutaneous inputs to lumbosacral dorsal horn neurons in the mouse spinal cord

Neuroscience ◽  
2016 ◽  
Vol 316 ◽  
pp. 13-25 ◽  
Author(s):  
K.E. Farrell ◽  
M.M. Rank ◽  
S. Keely ◽  
A.M. Brichta ◽  
B.A. Graham ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Mouse Spinal Cord ◽  
Dorsal Horn Neurons ◽  
In Vivo Characterization

In Vivo Characterization of Transport Anisotropy in Rat Spinal Cord Using Diffusion Tensor Imaging

2008 ◽  
Author(s):  
Xiaoming Chen ◽  
Garrett W. Astary ◽  
Thomas H. Mareci ◽  
Malisa Sarntinoranont
Keyword(s):  
Spinal Cord ◽  
Diffusion Tensor Imaging ◽  
Drug Transport ◽  
Diffusion Tensor ◽  
Local Drug Delivery ◽  
Imaging Method ◽  
Rat Spinal Cord ◽  
In Vivo Characterization

Biotransport in nervous tissues is complicated by the existence of neural fibers. These axonal fibers result in inhomogeneous and anisotropic extracellular transport, which complicates the prediction of local drug delivery such as convection-enhanced delivery [1]. Previous studies by our group [4] have shown that by using diffusion tensor imaging (DTI) [2, 3], anisotropic transport in rat spinal cord can be modeled using computational models, and consequently extracellular flows which influence drug transport can be well predicted. In previous studies, DTI-based models used data from an excised and fixed rat spinal cord. In the current study, we extend our DTI study to in vivo measures, and report the in vivo characterization of transport anisotropy in rat spinal cord. The MR imaging method is presented and the DTI data is discussed.

Erratum to “optical imaging of intrinsic signals induced by peripheral nerve stimulation in the in vivo rat spinal cord”

NeuroImage ◽  
2003 ◽  
Vol 18 (4) ◽  
pp. 1010
Author(s):  
Shinichi Sasaki ◽  
Itaru Yazawa ◽  
Naohisa Miyakawa ◽  
Hiraku Mochida ◽  
Kenichi Shinomiya ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Peripheral Nerve ◽  
Optical Imaging ◽  
Nerve Stimulation ◽  
Peripheral Nerve Stimulation ◽  
Rat Spinal Cord ◽  
Intrinsic Signals

Optical Imaging of Intrinsic Signals Induced by Peripheral Nerve Stimulation in the in Vivo Rat Spinal Cord

NeuroImage ◽  
2002 ◽  
Vol 17 (3) ◽  
pp. 1240-1255 ◽  
Author(s):  
Shinichi Sasaki ◽  
Itaru Yazawa ◽  
Naohisa Miyakawa ◽  
Hiraku Mochida ◽  
Kenichi Shinomiya ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Peripheral Nerve ◽  
Optical Imaging ◽  
Nerve Stimulation ◽  
Peripheral Nerve Stimulation ◽  
Rat Spinal Cord ◽  
Intrinsic Signals

scholarly journals Multi-compartmental diffusion characterization of the human cervical spinal cord in vivo using the spherical mean technique

2018 ◽  
Vol 31 (4) ◽  
pp. e3894 ◽  
Author(s):  
Samantha By ◽  
Junzhong Xu ◽  
Bailey A. Box ◽  
Francesca R. Bagnato ◽  
Seth A. Smith
Keyword(s):  
Spinal Cord ◽  
Cervical Spinal Cord ◽  
Spherical Mean

scholarly journals Characterization of DTI Indices in the Cervical, Thoracic, and Lumbar Spinal Cord in Healthy Humans

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Rachael L. Bosma ◽  
Patrick W. Stroman
Keyword(s):  
Spinal Cord ◽  
Mean Diffusivity ◽  
Lumbar Spinal Cord ◽  
Single Shot ◽  
Tissue Properties ◽  
Healthy Humans ◽  
Diffusion Weighted Images ◽  
Lumbar Spinal

The aim of this study was to characterizein vivomeasurements of diffusion along the length of the entire healthy spinal cord and to compare DTI indices, including fractional anisotropy (FA) and mean diffusivity (MD), between cord regions. The objective is to determine whether or not there are significant differences in DTI indices along the cord that must be considered for future applications of characterizing the effects of injury or disease. A cardiac gated, single-shot EPI sequence was used to acquire diffusion-weighted images of the cervical, thoracic, and lumbar regions of the spinal cord in nine neurologically intact subjects (19 to 22 years). For each cord section, FA versus MD values were plotted, and a k-means clustering method was applied to partition the data according to tissue properties. FA and MD values from both white matter (averageFA=0.69, averageMD=0.93×10−3 mm2/s) and grey matter (averageFA=0.44, averageMD=1.8×10−3 mm2/s) were relatively consistent along the length of the cord.

scholarly journals In vivo longitudinal Myelin Water Imaging in rat spinal cord following dorsal column transection injury

2014 ◽  
Vol 32 (3) ◽  
pp. 250-258 ◽  
Author(s):  
Piotr Kozlowski ◽  
Paulina Rosicka ◽  
Jie Liu ◽  
Andrew C. Yung ◽  
Wolfram Tetzlaff
Keyword(s):  
Spinal Cord ◽  
Dorsal Column ◽  
Rat Spinal Cord
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