REACTIVE ASTROGLIA NEURON RELATIONSHIPS IN THE HUMAN CEREBELLAR CORTEX - A QUANTITATIVE, MORPHOLOGICAL AND IMMUNOCYTOCHEMICAL STUDY IN CREUTZFELDT-JAKOB DISEASE
M. Lafarga et al., REACTIVE ASTROGLIA NEURON RELATIONSHIPS IN THE HUMAN CEREBELLAR CORTEX - A QUANTITATIVE, MORPHOLOGICAL AND IMMUNOCYTOCHEMICAL STUDY IN CREUTZFELDT-JAKOB DISEASE, International journal of developmental neuroscience, 11(2), 1993, pp. 199-213
In order to investigate the role of neuron-glia interactions in the re
sponse of astroglial to a non-invasive cerebellar cortex injury, we ha
ve used two cases of the ataxic form of Creutzfeldt-Jakob disease (CJD
) with distinct neuronal loss and diffuse astrogliosis. The quantitati
ve study showed no changes in cell density of either Purkinje or Bergm
ann glial cells in CJ-1, whereas in the more affected CJ-2 a loss of P
urkinje cells and an increase of Bergmann glial cells was found. The g
ranular layer in both CJD cases showed a similar loss of granule celts
(about 60%) in parallel with the significant increase in GFAP+ reacti
ve astrocytes. GFAP immunostaining revealed greater reactivity of Berg
mann glia in CJ-2 than in CJ-1, as indicated by the thicker glial proc
esses and the higher optical density. Granular layer reactive astrocyt
es were regularly spaced. In both CJD cases there was strict preservat
ion of the spatial arrangement of all astroglial subtypes-Fananas cell
s, Bergmann glia and granular layer astrocytes. Reactive Fananas and B
ergmann glial cells and microglia/macrophages expressed vimentin, whil
e only a few vimentin+ reactive astrocytes were detected in the granul
ar layer. Karyometric analysis showed that the increase in nuclear vol
ume in reactive astrloglia was directly related with the level of glia
l hypertrophy. The number of nucleoli per nuclear section was constant
in astroglial cells of human controls and CJD, suggesting an absence
of polyploidy in reactive astroglia. Ultrastructural analysis revealed
junctional complexes formed by the association of macula adherens and
gap junctions. In the molecular layer numerous vacant dendritic spine
s were ensheathed by lamellar processes of reactive Bergmann glia. Our
results suggest that quantitative (neuron/astroglia ratio) and qualit
ative changes in the interaction of neurons with their region-specific
astroglial partners play a central role in the astroglial response pa
ttern to the pathogenic agent of CJD.