Glutaminergic responses of neuropile glial cells and Retzius neurones in the leech central nervous system

Intracellular sodium homeostasis in rat hippocampal astrocytes.

“…Interestingly, in studies in which [Nae]i of both neurons and glial cells were determined for the same preparation (and with the same technique), glial [Nae], was always higher than neuronal [Nae]i (Buehrle & Sonnhof, 1983;Coles & Orkand, 1985;Doerner et al 1990). The meaning of this is not clear, but perhaps the higher glial [Na]i assists in K+ removal by insuring that [Nae]i is not the rate-limiting step for glial Na+,K+-ATPase activity, which contributes to K+ uptake (Sweadner, 1995).…”

“…Using radioisotope techniques, an [Na+]1 of 28-1 mm was calculated in cultured mouse astrocytes (Walz & Hertz, 1983). Glial [Nae], has also been measured in invertebrate preparations: aNa1 of glial cells in drone retina was 37 mm (Coles & Orkand, 1985), whereas aNa1 was 5-11 mm in leech neuropile glial cells (Doerner, Ballanyi & Schlue, 1990;Deitmer, 1991).…”

Intracellular acidification of the leech giant glial cell evoked by glutamate and aspartate

“…A reversible rise in Na i 1 , following glutamate aspartate or application could indeed be observed in leech glial cells Dörner et al, 1990) and in rat hippocampal astrocytes (Rose and Ransom, 1996).…”

5‐hydroxytryptamine‐mediated increase in glutamate uptake by the leech giant glial cell

“…The competitive glutamate uptake inhibitor THA, but not the blocker of ionotropic, non-NMDA glutamate receptors CNQX, reduced this current reversibly by 72%. Kainate is an agonist for ionotropic glutamate receptors and its application induces a multiphasic membrane response in the giant glial cells D€ orner et al, 1990). Contrary to D-asp, kainate (10 lM) induced a glial response, which was not blocked by THA, but instead by CNQX (Figs.…”