(A) RT-multiplex PCR amplification of different nAChR subunit sequences. (A, top) Hippocampal RNA (500 pg) was subjected to the RT-multiplex PCR protocol to detect the expression of different nAChR subunits (α2-α6). (A, bottom) RT-multiplex PCR applied on a single nicotine-responding interneuron after electrophysiological recording to detect expression of (α2-α6). An example of single-cell RT-multiplex PCR, showing the presence of α2 and α3 subunits in a recorded cell. RT-PCR products were separated by agarose gel electrophoresis and visualized with ethidium bromide. The amplified fragments had the sizes (in bp) predicted by the mRNA sequences: 300 (α2), 221 (α3), 265 (α4), 291 (α5), 367 (α6). A 100 bp DNA ladder was used as a molecular weight marker (A, top, M). (B) Summary data of single-cell RT-multiplex PCR.