THE occurrence of Cajal-Retzius (CjRe) cells was studied in four corti
cal areas of five normal adult humans using antibodies against calreti
nin. Calretinin immunofluorescence and autofluorescence of lipofusin g
ranules in CjRe cells were visualized by dual channel confocal laser s
canning microscopy. Three types of CjRe cells existed in the adult hum
an cortex: horizontal, triangular and multipolar, and their number did
not decrease with ageing. Horizontal CjRe cells were found in all cor
tical areas; they contained no lipofusin or less than other cells. Tri
angular CjRe cells with descending dendrites were less numerous. Multi
polar CjRe cells were rare and contained more lipofuscin. We conclude
that calretinin-immunoreactivity can be used to study CjRe cell morpho
logy in normal and diseased adult human brain.