Figure 5.

Chrna5^Cre-mediated reporter expression in the cerebral cortex. A–C, Expression of ZsGreen in the cerebral cortex of Chrna5^Cre mice from three founder lines interbred with the Ai6 reporter strain. Lines 1 and 3 exhibit low expression; line 2 exhibits appropriate expression in deep cortical layers, but expression is also seen sporadically in more superficial cells that appear to be clonal in origin and are likely to result from occasional developmental activation of the reporter (asterisks). Coronal sections at bregma 1.9. D, Colabeling of GABAergic interneurons in green (Gad67-GFP) and Chrna5^Cre neurons in red (Chrna5^Cre and Ai14/tdTomato). Inset detail shows that Chrna5^Cre neurons are exclusively excitatory pyramidal cells. Also shown is a coronal section at bregma 2.3. E, DFISH for Chrna5 and Gad1/Gad67 mRNA. Little overlap in expression is observed, but occasional Gad1-expressing cells appear to express low levels of Chrna5 (inset, arrows). Fml, Forceps minor, corpus callosum; DP, dorsal peduncular cortex; IL, infralimbic cortex; lv, lateral ventricle; Mo, motor cortex; PrL, prelimbic cortex. Scale bar, 200 μm. See Figure 5-1.