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Forschungsdatenbank PMU-SQQUID

Onset of aquaporin-4 expression in the developing mouse brain.
Fallier-Becker, P; Vollmer, JP; Bauer, HC; Noell, S; Wolburg, H; Mack, AF;
Int J Dev Neurosci. 2014; 36:81-89
Originalarbeiten (Zeitschrift)


Bauer Hans Christian


The main water channel in the brain, aquaporin-4 (AQP4) is involved in maintaining homeostasis and water exchange in the brain. In adult mammalian brains, it is expressed in astrocytes, mainly, and in high densities in the membranes of perivascular and subpial endfeet. Here, we addressed the question how this polarized expression is established during development. We used immunocytochemistry against AQP4, zonula occludens protein-1, glial fibrillary acidic protein, and β-dystroglycan to follow astrocyte development in E15 to P3 NMRI mouse brains, and expression of AQP4. In addition we used freeze-fracture electron microscopy to detect AQP4 in the form of orthogonal arrays of particles (OAPs) on the ultrastructural level. We analyzed ventral, lateral, and dorsal regions in forebrain sections and found AQP4 immunoreactivity to emerge at E16 ventrally before lateral (E17) and dorsal (E18) areas. AQP4 staining was spread over cell processes including radial glial cells in developing cortical areas and became restricted to astroglial endfeet at P1-P3. This was confirmed by double labeling with GFAP. In freeze-fracture replicas OAPs were found with a slight time delay but with a similar ventral to dorsal gradient. Thus, AQP4 is expressed in the embryonic mouse brain starting at E16, earlier than previously reported. However a polarized expression necessary for homeostatic function and water balance emerges at later stages around and after birth.

Useful keywords (using NLM MeSH Indexing)

Age Factors


Animals, Newborn

Aquaporin 4/metabolism*

Aquaporin 4/ultrastructure








Embryo, Mammalian

Freeze Fracturing

Gene Expression Regulation, Developmental/physiology*

Glial Fibrillary Acidic Protein/metabolism


Zonula Occludens-1 Protein/metabolism

Find related publications in this database (Keywords)

Orthogonal arrays of particles