INTRACELLULAR CALCIUM OSCILLATION IN LHRH CELLS FROM EMBRYONIC OLFACTORY PLACODE

目的了解LHRH脉冲式释放的机制， 以及培养的LHRH神经元是否表现出自发的细胞内 Ca 2+（[Ca 2 +]i）信号。 嗅板和腹板 恒河猴E35-37胚胎LHRH神经元的迁移途径 切下并在盖玻片上培养。 2至5周 随后培养的细胞用钙染料fura-2标记， 通过记录[Ca 2 +]i的变化来检查[Ca 2 +]i信号传导， 将细胞固定，并对LHRH和LHRH进行免疫染色。 神经元特异性烯醇化酶 在20个培养物中，572个LHRH阳性细胞 显示[Ca 2 +]i振荡，脉冲间隔（IPI）为 8.2（0.7 min），持续时间88.8（2.9 s. LHRH阴性神经元 培养物仅表现出偶尔的[Ca 2 +]i振荡。 20个中的17个 与LHRH阳性细胞一起培养，[Ca ~（2+）]i出现振荡 在50-100%的单个细胞中同步，而[Ca 2 +]i 其余3种培养物中细胞的振荡不同步。 引人注目的是，在17个培养物中的12个中，[Ca 2 +]i 振荡在52.8（3.0 min）时完全一致地重复发生 间隔，这是类似于观察到的LHRH释放的周期， 而在17个培养物中的5个中，[Ca 2 +]i 振荡以23.4（4.6分钟间隔）重复发生。 IPI [Ca2+]i振荡在具有紧密同步和更少同步的细胞中 紧同步与IPI在细胞中没有不同， 同步 结果表明，LHRH神经元来源于 猴嗅板具有内源性机制， [Ca 2 +]i振荡的同步化。 未来的方向我们将 确定[Ca 2 +]i振荡的同步是否是表现 周期性LHRH神经分泌。 关键词细胞内Ca 2 + 信号转导，细胞内钙振荡，同步化，LHRH 神经元，嗅板。 资助NIH HD 15433和RR 00167 Terasawa，E. LHRH搏动的细胞机制 release. 内分泌综合征 112 283-295，1998年。 （J）

OBJECTIVE To understand the mechanism of pulsatile LHRH release, and whether cultured LHRH neurons exhibit spontaneous intracellular Ca2+ ([Ca2+]i) signaling. The olfactory placode and the ventral migratory pathway of LHRH neurons from rhesus monkey embryos at E35-37 were dissected out and cultured on glass coverslips. Two to 5 weeks later cultured cells were labeled with the calcium dye, fura-2, and examined for [Ca2+]i signaling by recording changes in [Ca2+]i every 10 s for 30-175 min. Cells were fixed and immunostained for LHRH and neuron specific enolase. In 20 cultures, 572 LHRH-positive cells exhibited [Ca2+]i oscillations at an interpulse interval (IPI) of 8.2(0.7 min, and a duration of 88.8(2.9 s. LHRH-negative neurons in culture exhibited only occasional [Ca2+]i oscillations. In 17 of 20 cultures with LHRH-positive cells, [Ca2+]i oscillations occurred synchronously in 50-100% of the individual cells, whereas [Ca2+]i oscillations in cells in the remaining 3 cultures did not synchronize. Strikingly, in 12 of 17 cultures the synchronization of [Ca2+]i oscillations repeatedly occurred in complete unison at 52.8(3.0 min intervals, which is similar to the period observed for LHRH release, whereas in 5 of 17 cultures the less tight synchronization of [Ca2+]i oscillations repeatedly occurred at 23.4(4.6 min intervals. IPI of [Ca2+]i oscillations in cells with tight synchronization and less tight synchronization did not differ from IPI in cells without synchronization. The results indicate that LHRH neurons derived from the monkey olfactory placode possess an endogenous mechanism for synchronization of [Ca2+]i oscillations. FUTURE DIRECTIONS We will determine if synchronization of [Ca2+]i oscillations is manifestation of periodical LHRH neurosecretion. KEY WORDS intracellular Ca2+ signaling, intracellular Ca2+ oscillations, synchronization, LHRH neurons, olfactory placode. FUNDING NIH HD15433 & RR00167 PUBLICATIONS Terasawa, E. Cellular mechanism of pulsatile LHRH release. Gen. Comp. Endocrinol. 112 283-295, 1998. (J)