Glutamate and kainate increase intracellular sodium activity in leech neuropile glial cells

✍ Scribed by K. Ballanyi; Mrs. R. Dörner; W.-R. Schlue

• Book ID: 102224790
• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 300 KB
• Volume: 2
• Category: Article
• ISSN: 0894-1491
• DOI: 10.1002/glia.440020106

✦ Synopsis

Na+-selective, double-barrelled microelectrodes were used to measure intracellular Naf activity (ah,) and membrane potential (Em) in neuropile glial cells of isolated segmental ganglia in the leech Hirudo medicinalis. Bath application of glutamate M) resulted in membrane depolarizations of about 5 mV and a concomitant increase of a i a by between 2 and 10 mM. Kainate M) elicited depolarizations of up to 40 mV amplitude followed by a prominent afterhyperpolarization. During kainate, a& increased by 7 to 25 mM. In contrast to glutamate, a n initial decrease of a& was detected during the action of kainate. N-methyl-D-aspartate (NMDA, 10-5-10-3M) had no effect of Em and aka. The results indicate that leech glial cells have a kainate-preferring non-NMDA glutamate receptor.