The rhombencephalic recess in the rat. A light and electron microscopic study

Area of Science:

• Neuroscience
• Cell Biology
• Histology

Background:

• The rhombencephalic recess is an ependymal organ located in the rhomboid fossa.
• Its structure and function have not been previously studied in detail.

Purpose of the Study:

• To investigate the ultrastructure of the rhombencephalic recess using light and electron microscopy.
• To characterize the blood-brain barrier properties and vascular supply of this brain region.

Main Methods:

• Light and electron microscopy were employed to examine the rhombencephalic recess.
• Horseradish peroxidase (HRP) was used to assess the permeability of the blood-brain barrier.
• Vascular supply was analyzed through examination of arteries and capillaries.

Main Results:

• The rhombencephalic recess is composed of tanycytes with apically connected tight junctions.
• HRP did not penetrate intercellular clefts, indicating barrier integrity.
• The recess exhibits vascular autonomy with a blood-brain barrier showing localized leakage via vesicular transport.

Conclusions:

• The rhombencephalic recess possesses a distinct structure and blood-brain barrier characteristics.
• Its organization suggests specialized functions potentially differing from other ependymal organs.
• Further comparison with circumventricular organs is warranted.