Abstract
Primary cultures of neocortical neurons exhibit spontaneous Ca 2+ oscillations under zero or low extracellular [Mg2+] conditions. We find that mature murine neocortical neurons cultured for 9 days also produce spontaneous Ca2+ oscillations in the presence of physiological [Mg2+]. These Ca2+ oscillations were action potential mediated inasmuch as tetrodotoxin eliminated their occurrence. AMPA receptors were found to regulate the frequency of Ca2+ oscillations. In contrast, Ca2+ oscillations were independent of activation of L-type Ca2+ channels, and NMDA receptors provided only a minor contribution. Release of intracellular Ca2+ stores was involved in the oscillatory activity since thapsigargin reduced the amplitude and frequency of the oscillations. S-4-carboxyphenylglycine ((S)-4CPG), an antagonist of group I metabotropic glutamate receptor (mGluR), also reduced the amplitude of oscillations. In addition, 1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD), a group I mGluR agonist, increased the oscillation frequency, suggesting a critical role for mGluR in the generation of Ca2+ oscillations. The mGluR-mediated release of intracellular Ca2+ stores appeared to be mediated by phospholipase C (PLC) since the PLC inhibitor U73122 eliminated the Ca2+ oscillations. These results indicate that Ca2+ oscillations in neocortical cultures in the presence of physiologic [Mg2+] are primarily initiated by excitatory input from AMPA receptors and involve mobilization of intracellular Ca2+ stores following activation of mGluR.
| Original language | English |
|---|---|
| Pages (from-to) | 8-17 |
| Number of pages | 10 |
| Journal | Brain Research |
| Volume | 1006 |
| Issue number | 1 |
| DOIs | |
| State | Published - Apr 23 2004 |
| Externally published | Yes |
Fingerprint
All Science Journal Classification (ASJC) codes
- Neuroscience(all)
Cite this
Spontaneous synchronized calcium oscillations in neocortical neurons in the presence of physiological [Mg2+] : Involvement of AMPA/kainate and metabotropic glutamate receptors. / Dravid, Shashank M.; Murray, Thomas F.
In: Brain Research, Vol. 1006, No. 1, 23.04.2004, p. 8-17.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Spontaneous synchronized calcium oscillations in neocortical neurons in the presence of physiological [Mg2+]
T2 - Involvement of AMPA/kainate and metabotropic glutamate receptors
AU - Dravid, Shashank M.
AU - Murray, Thomas F.
PY - 2004/4/23
Y1 - 2004/4/23
N2 - Primary cultures of neocortical neurons exhibit spontaneous Ca 2+ oscillations under zero or low extracellular [Mg2+] conditions. We find that mature murine neocortical neurons cultured for 9 days also produce spontaneous Ca2+ oscillations in the presence of physiological [Mg2+]. These Ca2+ oscillations were action potential mediated inasmuch as tetrodotoxin eliminated their occurrence. AMPA receptors were found to regulate the frequency of Ca2+ oscillations. In contrast, Ca2+ oscillations were independent of activation of L-type Ca2+ channels, and NMDA receptors provided only a minor contribution. Release of intracellular Ca2+ stores was involved in the oscillatory activity since thapsigargin reduced the amplitude and frequency of the oscillations. S-4-carboxyphenylglycine ((S)-4CPG), an antagonist of group I metabotropic glutamate receptor (mGluR), also reduced the amplitude of oscillations. In addition, 1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD), a group I mGluR agonist, increased the oscillation frequency, suggesting a critical role for mGluR in the generation of Ca2+ oscillations. The mGluR-mediated release of intracellular Ca2+ stores appeared to be mediated by phospholipase C (PLC) since the PLC inhibitor U73122 eliminated the Ca2+ oscillations. These results indicate that Ca2+ oscillations in neocortical cultures in the presence of physiologic [Mg2+] are primarily initiated by excitatory input from AMPA receptors and involve mobilization of intracellular Ca2+ stores following activation of mGluR.
AB - Primary cultures of neocortical neurons exhibit spontaneous Ca 2+ oscillations under zero or low extracellular [Mg2+] conditions. We find that mature murine neocortical neurons cultured for 9 days also produce spontaneous Ca2+ oscillations in the presence of physiological [Mg2+]. These Ca2+ oscillations were action potential mediated inasmuch as tetrodotoxin eliminated their occurrence. AMPA receptors were found to regulate the frequency of Ca2+ oscillations. In contrast, Ca2+ oscillations were independent of activation of L-type Ca2+ channels, and NMDA receptors provided only a minor contribution. Release of intracellular Ca2+ stores was involved in the oscillatory activity since thapsigargin reduced the amplitude and frequency of the oscillations. S-4-carboxyphenylglycine ((S)-4CPG), an antagonist of group I metabotropic glutamate receptor (mGluR), also reduced the amplitude of oscillations. In addition, 1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD), a group I mGluR agonist, increased the oscillation frequency, suggesting a critical role for mGluR in the generation of Ca2+ oscillations. The mGluR-mediated release of intracellular Ca2+ stores appeared to be mediated by phospholipase C (PLC) since the PLC inhibitor U73122 eliminated the Ca2+ oscillations. These results indicate that Ca2+ oscillations in neocortical cultures in the presence of physiologic [Mg2+] are primarily initiated by excitatory input from AMPA receptors and involve mobilization of intracellular Ca2+ stores following activation of mGluR.
UR - http://www.scopus.com/inward/record.url?scp=1642301025&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=1642301025&partnerID=8YFLogxK
U2 - 10.1016/j.brainres.2004.01.059
DO - 10.1016/j.brainres.2004.01.059
M3 - Article
C2 - 15047019
AN - SCOPUS:1642301025
VL - 1006
SP - 8
EP - 17
JO - Brain Research
JF - Brain Research
SN - 0006-8993
IS - 1
ER -