[Transglial channels in the sympathetic ganglion of Rana temporaria].

Channel across thin layers of glial cells in the frog sympathetic ganglia are demonstrated by means of transmissive electron microscope. The channels have a diameter of 60-130 nm, provided with a structure at their openings and considered to be formed by plasmalemmal vesicles. In the thinnest layers it may be a single vesicle whose membrane fused simultaneously with plasmalemma of the opposite surfaces of layers; in the wider layers channels are formed by a chain of two or more vesicles fused with each other and plasmalemma. The transglial channels are demonstrated also in ganglia fixed during long lasting high frequency preganglionic stimulation (40 Hz, 20 min) and in high K+ concentration in bathing solution (8, 16 and 55 mM). Possible involvement of transglial channels and other forms of fluid phase endocytosis in glial cells in removing a surplus of K+ from nerve cells during their activity is discussed.