[Interrelationship between tanycytes and capillaries of the primary plexus of the portal system in rats during the perinatal period].

The establishment of tanycyte connections with the primary plexus of capillaries during the perinatal period in rats was examined by light and electron microscopy. At this very time, basal processes of matrix cells and, later of differentiated tanycytes reach the primary plexus. Morphological features of the transport process between the basal process terminals and perivascular space have been noticed. The contact zone of basal processes with the external basal membrane of the primary plexus increased gradually. This may be due to the formation of preterminal ramification of the basal processes and to the flattening of some terminals. In addition, starting from the 20th day of the prenatal life, synaptoid contacts of monoaminnergic axons with tanycyte basal processes are noticed to appear.