| Autor: |
Mara Almog, Alon Korngreen |
| Jazyk: |
angličtina |
| Rok vydání: |
2009 |
| Předmět: |
|
| Zdroj: |
PLoS ONE, Vol 4, Iss 4, p e4841 (2009) |
| Druh dokumentu: |
article |
| ISSN: |
1932-6203 |
| DOI: |
10.1371/journal.pone.0004841 |
| Popis: |
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. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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