Age-dependent changes in the regulation by external calcium ions of the phosphorylation of glial fibrillary acidic protein in slices of rat hippocampus

Brain Res Dev Brain Res. 1995 Apr 18;85(2):181-6. doi: 10.1016/0165-3806(94)00208-h.


We studied the effect of external Ca2+ on the incorporation of [32P]phosphate into the astrocytic marker protein, glial fibrillary acidic protein (GFAP), in hippocampal slices from rats in the postnatal age range 12-16 days to +60 days (P12-P16 to +P60). At age P12-P16 the presence of Ca2+ in the incubation medium inhibited the incorporation of 32P into GFAP; this inhibition declined to near zero by P21 and subsequently 32P-incorporation became progressively more dependent on Ca2+ until by P60 no GFAP phosphorylation was observed in the absence of Ca2+. With tissue from immature rats inhibition of 32P-incorporation into GFAP started at a medium concentration of 7.5 microM Ca2+, reached 50% at 100 microM and then remained constant up to 1 mM; with adults maximal phosphorylation required 1 mM Ca2+ in the medium. The inorganic Ca(2+)-channel blockers, Co2+ and Ni2+, and a high concentration of the L-type blocker, nifedipine, reversed the effects of external Ca2+ on GFAP phosphorylation. The results suggest a late developmental change in the compartmental disposition of Ca2+ in astrocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Animals
  • Astrocytes / metabolism
  • Autoradiography
  • Calcium / metabolism*
  • Calcium / pharmacology
  • Calcium Channels / metabolism
  • Calcium Channels / pharmacology
  • Female
  • Glial Fibrillary Acidic Protein / metabolism*
  • Hippocampus / metabolism*
  • Male
  • Nifedipine / pharmacology
  • Phosphates / metabolism
  • Phosphorylation
  • Rats
  • Rats, Wistar


  • Calcium Channels
  • Glial Fibrillary Acidic Protein
  • Phosphates
  • Nifedipine
  • Calcium