Cyclic GMP evoked calcium transients in olfactory receptor cell growth cones

Nitric oxide-induced calcium transients in growth cones are believed to be mediated by cyclic nucleotides. Because nitric oxide is thought to influenc e the development of olfactory receptor cells (ORCs), we have begun to expl ore the effect of cyclic nucleotides on ORC growth cones. Cultured ORCs wer e loaded with fluo-3 AM and confocal imaging was employed to monitor calciu m transients following cyclic nucleotide-gated channel activation. Applicat ion of 8-bromo-cGMP at the growth cone caused transient increases in fluore scence which were restricted to the growth cone and lasted tens of seconds. The signal was abolished by LY83583, an inhibitor of cyclic nucleotide-gat ed channels. 8-Bromo-cGMP also inhibited further extension of growth cones. The data indicate that ORC growth cones exhibit cGMP-dependent calcium tra nsients that are consistent with those generated by cyclic nucleotide-gated channels. NeuroReport 11:677-681 (C) 2000 Lippincott Williams & Wilkins.