Martínez-Galán J R, López-Bendito G, Luján R, Shigemoto R, Fairén A, Valdeolmillos M
Instituto de Neurociencias, CSIC, Universidad Miguel Hernández, Campus de San Juan, Apartado 18, 03550 San Juan de Alicante, Spain.
Eur J Neurosci. 2001 Mar;13(6):1147-54. doi: 10.1046/j.0953-816x.2001.01494.x.
Glutamate receptors have been linked to the regulation of several developmental events in the CNS. By using cortical slices of early postnatal mice, we show that in layer I cells, glutamate produces intracellular calcium (Ca(2+)) elevations mediated by ionotropic and metabotropic glutamate receptors (mGluRs). The contribution of mGluRs to these responses was demonstrated by application of tACPD, an agonist to groups I and II mGluRs, which evoked Ca(2+) increases that could be reversibly blocked by MCPG, an antagonist to groups I and II mGluRs. In the absence of extracellular Ca(2+), repetitive applications of tACPD or quisqualate, an agonist to group I mGluRs, elicited decreasing Ca(2+) responses that were restored by refilling a thapsigargin-sensitive Ca(2+) store. The use of specific group I mGluR agonists CHPG and DHPG indicated that the functional mGluR in layer I was of the mGluR1 subtype. Subtype specific antibodies confirmed the presence of mGlur1 alpha, but not mGluR5, in Cajal-Retzius (Reelin-immunoreactive) neurons.
谷氨酸受体已被证明与中枢神经系统中多种发育事件的调节有关。通过使用出生后早期小鼠的皮质切片，我们发现，在第I层细胞中，谷氨酸通过离子型和代谢型谷氨酸受体（mGluRs）介导细胞内钙（Ca(2+)）升高。应用I组和II组mGluRs的激动剂反式-ACPD可诱发Ca(2+)升高，而I组和II组mGluRs的拮抗剂MCPG可使其可逆性阻断，这证明了mGluRs对这些反应的作用。在无细胞外Ca(2+)的情况下，重复应用反式-ACPD或I组mGluRs的激动剂喹啉酸可引起Ca(2+)反应逐渐降低，而通过补充对毒胡萝卜素敏感的Ca(2+)储存库可恢复该反应。使用I组特异性mGluR激动剂CHPG和DHPG表明，第I层中的功能性mGluR为mGluR1亚型。亚型特异性抗体证实，在Cajal-Retzius（Reelin免疫反应性）神经元中存在mGlur1α，但不存在mGluR5。
