Involvement of Non‐Neuronal Cells in Entorhinal‐Hippocampal Reorganization Following Lesions
- 1 June 2000
- journal article
- review article
- Published by Wiley in Annals of the New York Academy of Sciences
- Vol. 911 (1) , 192-206
- https://doi.org/10.1111/j.1749-6632.2000.tb06727.x
Abstract
Entorhinal lesion leads to anterograde degeneration of perforant path fibers in their main hippocampal termination zones. Subsequently, remaining fibers sprout and form new synapses on the denervated dendrites. This degeneration and reorganization is accompanied by sequential changes in glial morphology and function. Within a few hours following the lesion, amoeboid microglia migrate into the zone of denervation. Some hours later, signs of activation can be seen on astrocytes in the zone of denervation, where both cell types proliferate and remain in an activated state for more than two weeks. These activated glial cells might be involved in lesion‐induced plasticity in at least two ways: (1) by releasing cytokines and growth factors which regulate layer‐specific sprouting and (2) by phagocytosis of axonal debris, because myelin sheaths act as obstacles for sprouting fibers in the central nervous system. Whereas direct evidence for the former is still missing, the latter was investigated using phagocytosis‐dependent labeling techniques. Both microglial cells and astrocytes incorporate axonal debris. Phagocytosing microglial cells develop the immune phenotype of antigen‐presenting cells, whereas astrocytes strongly express FasL (CD95L), which induces apoptosis of activated lymphocytes. Thus, the interaction of glial cells with immune cells might be another, previously underestimated, aspect of reorganization following entorhinal lesion.Keywords
This publication has 68 references indexed in Scilit:
- Myelin does not influence the choice behaviour of entorhinal axons but strongly inhibits their outgrowth length in vitroEuropean Journal of Neuroscience, 1999
- The anatomical organization of the rat fascia dentata: new aspects of laminar organization as revealed by anterograde tracing with Phaseolus vulgaris -Leucoagglutinin (PHAL)Brain Structure and Function, 1998
- Synaptic 5′-Nucleotidase Activity Reflects Lesion-Induced Sprouting within the Adult Rat Dentate GyrusExperimental Neurology, 1994
- The Process of Reinnervation in the Dentate Gyrus of Adult Rats: Temporal Relationship between Changes in the Levels of Glial Fibrillary Acidic Protein (GFAP) and GFAP mRNA in Reactive AstrocytesExperimental Neurology, 1993
- Oligodendrocyte- and myelin-associated inhibitors of neurite outgrowth: Their involvement in the lack of CNS regenerationExperimental Neurology, 1992
- Astrocytes are important for sprouting in the septohippocampal circuitExperimental Neurology, 1988
- Extracellular matrix derived from astrocytes stimulates neuritic outgrowth from PC12 cells in vitroDevelopmental Brain Research, 1987
- Progress in Facilitating the Recovery of Function after Central Nervous System TraumaAnnals of the New York Academy of Sciences, 1985
- Adult rat brain astrocytes support survival of both NGF-dependent and NGF-insensitive neuronesNature, 1979
- Maze performance in rats with hippocampal perforant paths lesions: Some aspects of functional recoveryPhysiology & Behavior, 1975