Effect of nerve section on perineuronal glial cells in the CNS of rat and cat

Cova, John L.; Aldskogius, Håkan

doi:10.1007/bf00315635

Cited by 10 publications

(1 citation statement)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other analyses in the same model emphasized astrocytic coverage from the start, noting relatively few microglia (Reisert et al, 1984). The latter was consistent with EM observations in cat spinal motoneurons, in which the microglia reaction is weaker compared to rodents (Cova and Aldskogius, 1984 enabling parsing out synapse detachment vs. microglia coverage (Chen, 1978). Axotomized sympathetic postganglionic neurons are also subject to synapse detachment but in this case, there is no microglia in the ganglia and detached synaptic boutons can be recognized at a distance from the cell body because, remarkably, the presynaptic active zone (PAZ) remains intact (Matthews and Nelson, 1975;Purves, 1975).…”

Section: The History Of "Synaptic Stripping" Over Motoneurons After Nsupporting

confidence: 83%

Synaptic Plasticity on Motoneurons After Axotomy: A Necessary Change in Paradigm

Álvarez

Rotterman

Akhter

et al. 2020

Front. Mol. Neurosci.

View full text Add to dashboard Cite

Motoneurons axotomized by peripheral nerve injuries experience profound changes in their synaptic inputs that are associated with a neuroinflammatory response that includes local microglia and astrocytes. This reaction is conserved across different types of motoneurons, injuries, and species, but also displays many unique features in each particular case. These reactions have been amply studied, but there is still a lack of knowledge on their functional significance and mechanisms. In this review article, we compiled data from many different fields to generate a comprehensive conceptual framework to best interpret past data and spawn new hypotheses and research. We propose that synaptic plasticity around axotomized motoneurons should be divided into two distinct processes. First, a rapid cell-autonomous, microglia-independent shedding of synapses from motoneuron cell bodies and proximal dendrites that is reversible after muscle reinnervation. Second, a slower mechanism that is microgliadependent and permanently alters spinal cord circuitry by fully eliminating from the ventral horn the axon collaterals of peripherally injured and regenerating sensory Ia afferent proprioceptors. This removes this input from cell bodies and throughout the dendritic tree of axotomized motoneurons as well as from many other spinal neurons, thus reconfiguring ventral horn motor circuitries to function after regeneration without direct sensory feedback from muscle. This process is modulated by injury severity, suggesting a correlation with poor regeneration specificity due to sensory and motor axons targeting errors in the periphery that likely render Ia afferent connectivity in the ventral horn nonadaptive. In contrast, reversible synaptic changes on the cell bodies occur only while motoneurons are regenerating. This cell-autonomous process displays unique features according to motoneuron type and modulation by local microglia and astrocytes and generally results in a transient reduction of fast synaptic activity that is probably replaced by embryonic-like slow GABA depolarizations, proposed to relate to regenerative mechanisms.

show abstract

Section: The History Of "Synaptic Stripping" Over Motoneurons After Nsupporting

confidence: 83%

Synaptic Plasticity on Motoneurons After Axotomy: A Necessary Change in Paradigm

Álvarez

Rotterman

Akhter

et al. 2020

Front. Mol. Neurosci.

View full text Add to dashboard Cite

show abstract

A morphological study of glial cells in the hypoglossal nucleus of the cat during nerve regeneration

Cova¹,

Aldskogius²

1985

J of Comparative Neurology

View full text Add to dashboard Cite

The cat hypoglossal nerve and nucleus have been used as a model for the study of the occurrence and time course of modifications in the size and composition of the perineuronal glial cell population as they relate to cytological changes in the nerve cell body and the initiation and progress of axon regeneration. Animals were killed at 2, 5, 10, 20, 35, 65, and 115 days after crush injury to the hypoglossal nerve. At 5 days after surgery, growth cones and regenerating unmyelinated axons were present at the lesion site, but no conspicuous changes were apparent in the nerve cell bodies. At 10 days after surgery, the granular endoplasmic reticulum was disaggregated and depleted. The elongation phase appeared to be completed at 20 days, as judged by the bilateral retrograde labeling of the hypoglossal nuclei with horseradish peroxidase. By 35 days, the cytoarchitecture of the nerve cell bodies and maturation of axons, as determined by a comparison of the relative frequency distribution of cross sectional areas proximal and distal to the lesion, were completely restored. Comparative quantitative light microscopic examination of the hypoglossal nuclei of intact and experimental animals failed to reveal any statistically significant differences in the total number of glial cells, number of glial cells/unit area of neuropil, or relative proportions of glial cell types at any of the postoperative time intervals. Moreover, electron microscopic quantitation of the microglial cell population did not reveal any significant alterations in the number, density, location, or morphology of these cells.(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

A quantitative analysis of the microglial cell reaction in central primary sensory projection territories following peripheral nerve injury in the adult rat

et al. 1993

View full text Add to dashboard Cite

The time course of the microglial cell reaction in central nervous system primary sensory projection territories has been examined following peripheral nerve injury in the adult rat using qualitative and quantitative analysis of immunoreactivity with the monoclonal antibody OX-42, which recognises the complement receptor CR3. The regions examined included the gracile nucleus, the column of Clarke and the spinal cord dorsal horn (superficial and deep laminae separately) after unilateral sciatic nerve transection, and the spinal trigeminal nucleus following unilateral infraorbital nerve transection. In all territories examined a qualitative increase in OX-42 immunoreactivity was observed 24 h postlesion. Further, quantitative analysis revealed an exponential development of the OX-42 immunoreactivity, with a peak at one week postlesion, thereafter showing a slow exponential decline. Our results show that the signal (or signals) that induces the microglial cell response in primary sensory projection territories is rapid in comparison to previously described central degenerative changes following peripheral nerve lesions (transganglionic degeneration). These findings are compatible with the hypothesis that activated microglia play a pathogenetic role in the development of transganglionic degeneration.

show abstract

Effect of nerve section on perineuronal glial cells in the CNS of rat and cat

Cited by 10 publications

References 30 publications

Synaptic Plasticity on Motoneurons After Axotomy: A Necessary Change in Paradigm

Synaptic Plasticity on Motoneurons After Axotomy: A Necessary Change in Paradigm

A morphological study of glial cells in the hypoglossal nucleus of the cat during nerve regeneration

A quantitative analysis of the microglial cell reaction in central primary sensory projection territories following peripheral nerve injury in the adult rat

Contact Info

Product

Resources

About