Functional NMDA and GABAA receptors in pioneer neurons of the cortical marginal zone.
Transient pioneer neurons in the neocortical marginal zone generate an early corticofugal axonal projection at E12-E16 (Meyer et al. 1998). We have analysed the functional activity of glutamate and GABA receptors in such cells by measuring changes in intracellular calcium concentrations ([Ca2+]i). The activation of GABAA receptors with muscimol, as well as bath application of glutamate, lead to increases in [Ca2+]i in pioneer neurons. The stimulatory action of glutamate is mostly produced through the NMDA-type of ionotropic receptors. Metabotropic glutamate receptor activation has no effect on [Ca2+]i. Consistent with such results, immunocytochemical studies showed a prominent expression of GABAA and NMDA receptors in pioneer neurons. The activation of such receptors may be implicated in the remodelling of pioneer neurons during development.
Soria
J M
JM
Instituto de Neurociencias, CSIC, Universidad Miguel-Hernández, Campus de San Juan, San Juan de Alicante, Spain.
Martínez-Galán
J R
JR
Luján
R
R
Valdeolmillos
M
M
Fairén
A
A
D000818:Animals; D064026:Calbindins; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D005260:Female; D005456:Fluorescent Dyes; D016257:Fura-2; D058785:GABA-A Receptor Agonists; D007150:Immunohistochemistry; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000187:drug effects*; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists / Q000187:drug effects*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism
D064026:Calbindins; D018690:Excitatory Amino Acid Agonists; D005456:Fluorescent Dyes; D058785:GABA-A Receptor Agonists; D011963:Receptors, GABA-A; D016194:Receptors, N-Methyl-D-Aspartate; D064030:S100 Calcium Binding Protein G; D002118:Calcium; D016257:Fura-2