Cellular deletion studies indicated that taurine was not present (or present in relatively low amounts) in granule cells but appeared to be present in relatively high amounts in the inhibitory stellate cells as well as the excitatory climbing fibers in the cerebellum of the rat. Microdissection of the cerebellum demonstrated that the content of taurine was significantly higher in the molecular layer than in the granular layer, white matter or deep nuclei. The level of taurine was threefold greater than the level of γ-aminobutyric acid (GABA) in the molecular layer and the distribution pattern of taurine among the four cerebellum regions was different than that of GABA. Microiontophoretic application of taurine induced an inhibition of spike discharge in 88% of the Purkinje cells and of other cerebellar neurons tested. Taurine appeared to be one-half to one-fifth as potent as GABA in the cerebellum. Microiontophoretic application of bicuculline or picrotoxin antagonized the inhibitory effects produced by GABA or taurine whereas strychnine did not. Simultaneous application of taurine and GABA had a synergistic inhibitory effect, suggesting separate receptor sites. Radioactive taurine could be released from the cerebellar cortex in a Ca2+ dependent manner either by elevated K+ levels or by electrical stimulation. The data are consistent with a possible role for taurine as the inhibitory transmitter released from stellate cells. In addition, taurine might serve another, yet unknown, role in the cerebellum, since it appears to be present in the excitatory climbing fibers of the cerebellum.
|Original language||English (US)|
|Number of pages||5|
|State||Published - Jan 1 1980|
ASJC Scopus subject areas