Characterization of voltage-gated Ca(2+) conductances in layer 5 neocortical pyramidal neurons from rats.
Neuronal voltage-gated Ca(2+) channels are involved in electrical signalling and in converting these signals into cytoplasmic calcium changes. One important function of voltage-gated Ca(2+) channels is generating regenerative dendritic Ca(2+) spikes. However, the Ca(2+) dependent mechanisms used to...
Guardado en:
| Autores principales: | , |
|---|---|
| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
Public Library of Science (PLoS)
2009
|
| Materias: | |
| Acceso en línea: | https://doaj.org/article/04ed304544e74087b361e407c220aa91 |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| Sumario: | Neuronal voltage-gated Ca(2+) channels are involved in electrical signalling and in converting these signals into cytoplasmic calcium changes. One important function of voltage-gated Ca(2+) channels is generating regenerative dendritic Ca(2+) spikes. However, the Ca(2+) dependent mechanisms used to create these spikes are only partially understood. To start investigating this mechanism, we set out to kinetically and pharmacologically identify the sub-types of somatic voltage-gated Ca(2+) channels in pyramidal neurons from layer 5 of rat somatosensory cortex, using the nucleated configuration of the patch-clamp technique. The activation kinetics of the total Ba(2+) current revealed conductance activation only at medium and high voltages suggesting that T-type calcium channels were not present in the patches. Steady-state inactivation protocols in combination with pharmacology revealed the expression of R-type channels. Furthermore, pharmacological experiments identified 5 voltage-gated Ca(2+) channel sub-types - L-, N-, R- and P/Q-type. Finally, the activation of the Ca(2+) conductances was examined using physiologically derived voltage-clamp protocols including a calcium spike protocol and a mock back-propagating action potential (mBPAP) protocol. These experiments enable us to suggest the possible contribution of the five Ca(2+) channel sub-types to Ca(2+) current flow during activation under physiological conditions. |
|---|