Calbindin-D28k content and firing pattern of hippocampal granule cells in amygdala-kindled rats: a perforated patch-clamp study

Brain Res. 2005 Jan 25;1032(1-2):123-30. doi: 10.1016/j.brainres.2004.10.060.


The dentate gyrus is believed to play an important pathophysiological role during experimentally induced kindling. In this study, we investigated whether an altered content of the calcium binding protein calbindin-D(28k) or an increased intrinsic excitability of hippocampal granule cells contribute to the induction of the kindling phenomenon. We determined the firing pattern of granule cells in hippocampal slices using perforated patch-clamp recordings in current clamp mode. The expression of calbindin-D(28k) and glutamic acid decarboxylase (GAD(67)) by granule cells was analyzed immunohistochemically. Rats developed secondarily generalized limbic seizures within approximately 11 days of twice-daily stimulation of the amygdala. As reported for other kindling paradigms, this protocol induced a clear up-regulation of GAD(67) in granule cells, indicating their involvement in the induced neuronal activity. However, when comparing kindled and control rats, we could not detect any differences in intrinsic excitability: Firing frequency, after-hyperpolarisations, action potentials, input resistance and membrane potentials were nearly identical between both groups. Furthermore, we did not observe any differences in the calbindin-D(28k) immunoreactivity between groups. In every slice, virtually all granule cells were found to be strongly calbindin-D(28k) positive, and there was no apparent reduction in the general level of calbindin-D(28k) expression. We conclude that changes in intrinsic membrane properties or in the calbindin-D(28k) content of granule cells are not necessary for the development of amygdala kindling.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology*
  • Action Potentials / radiation effects
  • Amygdala / radiation effects
  • Animals
  • Calbindin 1
  • Calbindins
  • Cell Count / methods
  • Electric Stimulation / methods
  • Glutamate Decarboxylase / metabolism
  • Hippocampus / cytology*
  • Immunohistochemistry / methods
  • In Vitro Techniques
  • Isoenzymes / metabolism
  • Kindling, Neurologic / physiology*
  • Male
  • Neurons / physiology*
  • Patch-Clamp Techniques / methods
  • Rats
  • Rats, Sprague-Dawley
  • S100 Calcium Binding Protein G / metabolism*


  • Calb1 protein, rat
  • Calbindin 1
  • Calbindins
  • Isoenzymes
  • S100 Calcium Binding Protein G
  • Glutamate Decarboxylase
  • glutamate decarboxylase 1