Receptor-activated calcium signals in tangentially migrating cortical cells

Cereb Cortex. 2002 Aug;12(8):831-9. doi: 10.1093/cercor/12.8.831.

Abstract

Recent studies have shown that the two main types of cortical neurons, pyramidal and nonpyramidal, have different origins and use different migratory routes--radial and tangential respectively. The role of neurotransmitters in radial migration is well known; however, there are no data about their effect on intracellular calcium--[Ca(2+)](i)--in tangentially migrating cells. We have performed ratiometric and confocal calcium imaging of 1,1'-dioctodecyl-3,3,3',3'-tetramethylindocarbocyanine labelled tangentially migrating neurons in the intermediate zone cells of fetal rat coronal slices. Superfusion with N-methyl-D-aspartic acid (NMDA) leads to an increase in [Ca(2+)](i), which is blocked by the antagonist APV or the presence of Mg(2+) in the medium. Kainate produced an increase in [Ca(2+)](i) that could be blocked by the non-NMDA antagonist CNQX. Muscimol, an agonist of GABAa-receptors, produced a transitory increase in [Ca(2+)](i) that was blocked by the specific antagonist bicuculline or the presence of tetrodotoxin in the medium. We conclude that tangentially migrating cells display consistent [Ca(2+)](i) changes in response to agonists of NMDA, non-NMDA and GABAa receptors, suggesting that these cells are quite mature and homogeneous. The endogenous activation of these receptors may have either a direct effect on tangential migration or modulate the response of migrating cells to external cues.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2-Amino-5-phosphonovalerate / pharmacology
  • 6-Cyano-7-nitroquinoxaline-2,3-dione / pharmacology
  • Anesthetics, Local / pharmacology
  • Animals
  • Calcium / metabolism
  • Calcium Signaling / drug effects
  • Calcium Signaling / physiology*
  • Cell Movement / physiology*
  • Cerebral Cortex / cytology*
  • Excitatory Amino Acid Agonists / pharmacology
  • Excitatory Amino Acid Antagonists / pharmacology
  • Female
  • GABA Agonists / pharmacology
  • GABA-A Receptor Agonists
  • Kainic Acid / pharmacology
  • Male
  • Muscimol / pharmacology
  • N-Methylaspartate / pharmacology
  • Neurons / cytology*
  • Neurons / physiology
  • Organ Culture Techniques
  • Pregnancy
  • Rats
  • Rats, Wistar
  • Receptors, GABA-A / physiology
  • Receptors, Glutamate / physiology
  • Tetrodotoxin / pharmacology

Substances

  • Anesthetics, Local
  • Excitatory Amino Acid Agonists
  • Excitatory Amino Acid Antagonists
  • GABA Agonists
  • GABA-A Receptor Agonists
  • Receptors, GABA-A
  • Receptors, Glutamate
  • Muscimol
  • Tetrodotoxin
  • N-Methylaspartate
  • 6-Cyano-7-nitroquinoxaline-2,3-dione
  • 2-Amino-5-phosphonovalerate
  • Kainic Acid
  • Calcium