GLUTAMATE MODULATES INTRACELLULAR CA2-STEM AUDITORY NEURONS( STORES IN BRAIN)

1. Fura-2 imaging was used to measure the effects of glutamate on caff eine-sensitive Ca2+ stores in neurons of the avian cochlear nucleus, n . magnocellularis (NM). 2. On average, 100-mM caffeine stimulated a 25 0-nM increase in intracellular calcium ion concentration {[Ca2+](i)} i n Ca2+-free media; 1-mM glutamate significantly attenuated caffeine-st imulated Ca2+ responses. 3. The metabotropic glutamate receptor agonis t, ACPD, also inhibited the caffeine-stimulated rise in [Ca2+](i). 4. Glutamate has an important role in regulating Ca2+ stores in NM neuron s. Glutamate-deprivation (viz. cochlear removal) results in a rise in [Ca2+](i) that may, in part, be the result of release from Ca2+ stores . We hypothesize that Ca2+-induced Ca2+ release stores (CICRs) may be involved in deprivation-induced cell death.