K. Vio et al., Hydrocephalus induced by immunological blockage of the subcommissural organ-Reissner's fiber (RF) complex by maternal transfer of anti-RF antibodies, EXP BRAIN R, 135(1), 2000, pp. 41-52
Stenosis of the cerebral aqueduct seems to be a key event for the developme
nt of congenital hydrocephalus. The causes of such a stenosis are not well
known. Overholser et al, in 1954 (Anat Rec 120:917-933) proposed the hypoth
esis that a dysfunction of the subcommissural organ (SCO) leads to aqueduct
al stenosis and congenital hydrocephalus. The SCO is a brain gland, located
at the entrance of the cerebral aqueduct, that secretes glycoproteins into
the cerebrospinal fluid that, upon release, assemble into a fibrous struct
ure known as Reissner's fiber (RF). By the permanent addition of new molecu
les to its rostral end, RF grows and extends along the aqueduct, fourth ven
tricle, and central canal of the spinal cord. The immunological blockage of
the SCO-RF complex has been used to test Overholser's hypothesis. The foll
owing was the sequence of events occurring in pregnant rats that had been i
mmunized with RF glycoproteins: the mother produced anti-RF antibodies and
transferred them to the fetus through the placenta and to the pup through t
he milk, and the antibodies reached the brain of the fetus and pup and bloc
ked the SCO-RF complex. This resulted in a permanent absence of RF that was
followed by stenosis of the cerebral aqueduct, and then by the appearance
of hydrocephalus. The latter was patent until the end of the 6-month observ
ation period. The chronic hydrocephalic state appeared, in turn, to induce
new alterations of the SCO. It is concluded that a selective immunological
knock out of the SCO-RF complex leads to hydrocephalus.