MembraneOptical illustration of glutamate-induced cell swelling coupled with membrane depolarization in embryonic brain stem slicesSato, Katsushige1; Momose-Sato, Yoko1; Arai, Yoshiyasu1; Hirota, Akihiko2; Kamino, Kohtaro1,3Author Information 1Department of Physiology, Tokyo Medical and Dental University School of Medicine, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113, Japan 2Present address: Department of Physiology, Shimane Medical University, Izumo-shi, Shimane 693, Japan 3Corresponding Author: Kohtaro Kamino Received 6 August 1997; accepted 23 August 1997 NeuroReport: November 10th, 1997 - Volume 8 - Issue 16 - p 3559-3563 Buy SDC Abstract USING intrinsicand voltage-sensitive dye optical recordings, we have elucidated coupling of glutamateinduced depolarization and neuronal swelling in early embryonic chick brain stem slices. Twenty-four slices were prepared from 8-day old chick embryos, and stained with a voltage-sensitive merocyanine-rhodanine dye (NK2761). The pressure ejection of glutamate to one site within the preparation evoked changes in transmitted light intensity. With 700 nm incident light, three components were identified in glutamate-induced optical changes. The first component was wavelength dependent, while the second and third components were independent of the wavelength. With reference to the action spectrum of the merocyanine-rhodanine dye and osmotic changes in optical properties, we concluded that the first component reflects glutamate-induced depolarization of the membrane, and that the second component is an intrinsic light-scattering change resulting from neural cell swelling coupled with the membrane depolarization. © Lippincott-Raven Publishers.