In acutely dissociated rat medium-spiny neostriatal neurons, a substantial fraction (~40%) of the calcium current block by ω-conotoxin-GVIA (CgTx) reverses rapidly with washing. The reversibly blocked current differed in voltage dependence from the current irreversibly blocked by CgTx. To test the hypothesis that reversibly blocked current was attributable to calcium channels with a class D α1 subunit, acutel isolated neurons were subjected to combined patch clamp/reverse transcription-polymerase chain reaction analysis. These studies revealed no correlation between the reversibility of the CgTx block and the expression of class D α1 subunit mRNA.
- Bay K 8644
- N-type calcium channels