Neuronal hyperactivity following deafferentation of the lateral cuneate nucleus

Kjerulf, Terrell D.; Loeser, John D.

doi:10.1016/0014-4886(73)90042-3

Cited by 56 publications

(14 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This burst detection scheme is utilized by the programs which make rasters and histograms . This scheme is not infallible ; indeed, one can detect occasional examples of the inclusion of nonbursts in the burst rasters in this paper and the previous paper (14) . Sampling time bins were 0 .2 c osec .…”

Section: Methodsmentioning

confidence: 48%

“…This paper utilizes a portion of the anatomical and physiological data reported separately in two other papers (14,19) . Adult cats (2-5 kg) with survival times of 24 and 45 hr, 6, 10 and 16 days, have been selected to correlate the structural and functional changes observed after Ci-T7 dorsal rhizotomv .…”

Section: Methodsmentioning

confidence: 99%

“…Two animals for each survival time were used, one for physiological and the other for anatomical studies . The surgical techniques employed to accomplish the deafferentation have been described in detail (14,19) . They are the same for each member of a pair of animals except that the T i root was preserved in the animals for physiological recording to allow characterization of units retaining their peripheral receptive field in the deafferented nucleus .…”

Section: Methodsmentioning

confidence: 99%

“…They are the same for each member of a pair of animals except that the T i root was preserved in the animals for physiological recording to allow characterization of units retaining their peripheral receptive field in the deafferented nucleus . The methods of tissue fixation and handling for electron microscopy, as well as the techniques for physiological recording, have been described in detail in our previous papers (14,19) .…”

Section: Methodsmentioning

confidence: 99%

“…Our previous papers (14,19) have described in detail the neurophysiological and fine structural features of this form of partial deafferentation .…”

mentioning

confidence: 99%

See 4 more Smart Citations

Deafferentation effects in lateral cuneate nucleus of the cat: Correlation of structural alterations with firing pattern changes

Kjerulf

O'Neal

Calvin

et al. 1973

Experimental Neurology

Self Cite

View full text Add to dashboard Cite

A correlated anatomical and physiological investigation of the effects of unilateral cervicothoracic dorsal rhizotomies upon lateral cuneate nucleus of the cat (LCN) is reported. Pairs of adult cats with identical survival times were selected to correlate structural and functional changes . Two phases are described in the development of alterations of neuronal firing patterns . In the first phase, a relative silence within LCN was associated with depletion of round synaptic vesicles in the presynaptic profiles (LR boutons) of primary dorsal root afferents . The second phase was characterized by a development of spontaneous electrical hyperactivity which corresponded anatomically to the presence of denuded postsynaptic specializations, transient increase of adjacent extracellular space and an apparent decrease in the number of dendritic spines . There was a persistence of an unaltered population of small presynaptic boutons with flattened vesicles (SF boutons) . The LCN neuronal membrane is viewed as having an intrinsic tendency for repetitive firing which is enhanced by the functional effects of denuded postsynaptic specialization . A marked similarity was found between some of the spontaneous firing patterns of normal animals (doublets) and the high frequency bursting firing pattern in deafferented preparation. Three models for repetitive spike production are considered in our analysis : oscillator-produced spikes ; EP SP-produced spikes ; and spike-evoked spikes . The spike-evoked spikes model is considered to be the 1 The authors thank

show abstract

Section: Methodsmentioning

confidence: 48%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…Our previous papers (14,19) have described in detail the neurophysiological and fine structural features of this form of partial deafferentation .…”

mentioning

confidence: 99%

See 3 more Smart Citations

Deafferentation effects in lateral cuneate nucleus of the cat: Correlation of structural alterations with firing pattern changes

Kjerulf

O'Neal

Calvin

et al. 1973

Experimental Neurology

Self Cite

View full text Add to dashboard Cite

show abstract

Restitution of function and collateral sprouting in the cat spinal cord: The partially hemisected animal

Murray

Goldberger

1974

J of Comparative Neurology

327

102

View full text Add to dashboard Cite

The hypothesis that collateral sprouting might be correlated with recovery of function was tested by a combination of behavioral and anatomical studies. Partial hemisections, sparing the dorsal columns, were made between T l r and L1 of cat spinal cord. Initially, all reflex and locomotor hindlimb activity was depressed ipsilaterally. During two postoperative weeks behavioral and electromyographic responses increased in response to intrinsic reflex elicitation but not to descending or crossed reflex elicitation. Marked improvement in use of the limb occurred as intrinsic reflex activity increased and became, in some cases, hyperactive. The status then remained stable for ten months. Since intrinsic reflexes are mediated by ipsilateral dorsal roots, the intraspinal distribution of L5 or L,; dorsal roots was determined by degeneration methods ten months after hemisection or by quantitative radioautography 20 days after hemisection. By both methods, the dorsal root distribution was found to be asymmetrical in the spinal gray. It was greater on the experimental side and the distribution was altered, having a greater distribution medially in Rexed's lamina VI and laterally in lamina VII. These anatomical changes are considered as signs of collateral sprouting from dorsal roots in response to degeneration of descending tracts on the same side. Dorsal root distribution to dorsal horn (laminae I-IV), motor nuclei, and nucleus gracilis is symmetrical. Regions of increased and of expanded dorsal root input can be correlated with electrophysiologically determined location of interneurons in the path of cutaneous reflexes and of stretch reflex facilitation. Behavioral and anatomical changes were selective; intrinsic reflexes recovered or became hyperactive and ipsilateral dorsal roots showed evidence of collateral sprouting during the recovery period, although a causal relationship between the two cannot be proven, by the present experiments.

show abstract

Patterns of degeneration in the external cuneate nucleus after multiple dorsal rhizotomies

Rosenstein

Page

Leure-Dupree

1977

J of Comparative Neurology

View full text Add to dashboard Cite

Unilateral, intradural dorsal rhizotomies (C3-Cs) were performed on adult rats to study the patterns of synaptic organization of ascending dorsal root fibers in the external cuneate nucleus (ECN). Animals were permitted to survive for periods of time ranging from 3 hours to 12 days. Sham-operated animals presented a morphology indistinguishable from that of normal, unoperated animals. In rhizotomized animals, degeneration was observed ipsilaterally at all survival periods. After postoperative survivals of 3 to 14 hours some terminal boutons displayed clumping and diminution in numbers of synaptic vesicles and, in addition, degeneration myelinated axons were observed at this time. There was considerable degeneration in the neuropil between 24 and 48 hours postoperative. Two forms of degeneration occurred in axons and terminal boutons with comparable frequency: electron lucent degeneration and electron opaque degeneration. Reactive phagocytic glial cells contained degenerated masses, lipoid droplets, lysosome-like structures and myelin fragments. After postoperative survivals of four to six days, lucent and opaque degenerating terminals were less numerous. Neurofilamentous degeneration was observed only occasionally. Unaltered synaptic membrane specializations were present and were usually abutted by glia. At 12 days postoperative, synaptic glomeruli and serial synapses were not seen. Invaginating dendritic spines were rarely seen. Bouton populations that remained unualtered were: small (0.3-3.0 micron) boutons that contact dendritic shafts and somata, nodal synaptic boutons and boutons containing granular vesicles (80-100 nm).

show abstract

Neuronal hyperactivity following deafferentation of the lateral cuneate nucleus

Cited by 56 publications

References 35 publications

Deafferentation effects in lateral cuneate nucleus of the cat: Correlation of structural alterations with firing pattern changes

Deafferentation effects in lateral cuneate nucleus of the cat: Correlation of structural alterations with firing pattern changes

Restitution of function and collateral sprouting in the cat spinal cord: The partially hemisected animal

Patterns of degeneration in the external cuneate nucleus after multiple dorsal rhizotomies

Contact Info

Product

Resources

About