Ribosome-associated membrane contacts between astrocytes in the anoxic brain.

Between adjacent astrocytes in cerebral and particularly cerebellar cortices of brains unsuccessfully perfused or subjected to 2-30 min anoxia or short (5 h) autolysis, a new distinct unusual variant of an intercellular apposition was observed, which derived from already pre-existing membrane contacts. This membrane apposition was characterized by thicker contacting plasma membranes than usual, narrower intercellular distance, a fine para- and intermembranous material and ribosomes in the paramembranous position. In addition to these ribosome-associated membrane appositions ribosomes-associated gap junction and microtubule-associated junction were observed in isolated cases. The reason for binding of ribosomes and microtubules to the plasma membrane and their function in this site is unknown.