Morphological changes in the mink area postrema during growth and under different stages of sexual activity

The histological features of the area postrema (AP) of mink brains of both sexes were investigated at different ages and physiological conditions with light and electron microscopy. The mink AP was a twin-winged structure located at the dorsal surface of the medulla oblongata and consisted of neurons, glial cells, and both continuous and fenestrated capillaries enmeshed in a rich neuropil. The ventricular surface of the mink AP was covered by a single layer of tanycytes except at its most caudal part that was covered by a basal membrane derived from the pia mater. Supraependymal cells and intraventricular axons were also a common finding over the apical poles of tanycytes. However, our study demonstrates that the mink AP acquires the above general features at an advanced postnatal time and that, once fully developed, it undergoes morphological changes that can be directly linked to the aging process and sexual activity of the animals.