AGE-RELATED EXPRESSION OF THE CD15 (3-FUCOSYL-N-ACETYL-LACTOSAMINE) EPITOPE IN THE MONKEY (CERCOPITHECUS-AETHIOPS-AETHIOPS L) LATERAL GENICULATE-NUCLEUS

The profile of the CD15 epitope-expression was studied in the lateral geniculate nucleus (LGN) of a monkey species (Cercopithecus aethiops a ethiops L.) during the peri- and postnatal development. Intense labeli ng of the neuropil and of astroglial cells was detected. Morphological examination of the spatio-temporal appearance of the CD15-expression showed different consecutive patterns of expression: expression of the CD15 epitope was high one week prenatally and during the first postna tal weeks. During this perinatal period it was mainly expressed in the interlaminar zone of the magnocellular portion of the LGN. This was f ollowed by a time period when immunoreactivity gradually decreased to become almost absent by approximately 10 weeks of age. Toward adulthoo d a different pattern of immunoreactivity occurred, revealing a patter n of lamination that was attributable to CD15 positive astrocytes, mos t prominent in the cellular layers 1 and 2. They were later on seen sp read out through the entire LGN such that the LGN of adult animals was entirely filled with positive material. From the temporal correlation of CD15-expression and LGN histogenesis it is concluded that the high level of CD15, that is observed in the neuropil during the perinatal period, matches with high synaptic plasticity within the visual system ; in contrast, low levels of CD15-expression correlate with synaptic r eorganization processes.