Figure 7.

Decreased formation of protein/DNA complex C1 correlates with down-regulation of β1 mRNA, [³H]flunitrazepam binding, and β1 subunit protein. Neocortical cells were exposed to 500 μM GABA. (A and B) EMSA using 30 μg of nuclear extracts shows decreased formation of C1 (n = 3), (C) RNase protection shows decreased levels of β1 mRNAs (n = 3), and (D) radioligand binding using [³H]flunitrazepam and quantitative Western blot analysis of β1 subunit protein levels, n = 3, show down-regulation of functional receptor and subunit. Quantitation was by densitometry (D) or phosphorimaging (B and C).