FIGURE 5.
GABAAR internalization in neurons is increased by muscimol. A, internalized labeling was obtained after incubating live cultured hippocampal neurons with a polyclonal antibody directed at the extracellular domain of the native α1 subunit at 37 °C (Internalized). Total staining of the same neurons was performed after permeabilization and labeling with a monoclonal antibody directed at the intracellular domain of the native α1 subunit (total). Arrows, labeling of internalized receptors; arrowheads, labeling of the intracellular domain. Scale bar, 10 μm. B, quantitative analysis of the area of intracellular punctate labeling of internalized receptors formed by α1 subunits in dendrites of neurons incubated in culture medium (control), with muscimol, gabazine (gbz), or picrotoxin (ptx); a total of four experiments on independent neuron cultures where carried out, with the number of quantified neurons going from n = 32 to 40. **, p < 0.005. Error bars, S.E.