<i>rl</i>¹ and <i>rut</i>²⁰⁸⁰ have deficits in ERK activation and structural plasticity in response to social enrichment.

<p><i>A</i>, In contrast to <i>Cs</i> controls, flies mutant for <i>rl</i>¹ or <i>rut</i>²⁰⁸⁰ do not exhibit an increase in ERK activation following social enrichment. Representative Western blot for ppERK and totERK in flies exposed to social enrichment and social isolation (4 heads/lane). <i>B</i>, Quantification of the Western blot in (<i>A</i>) for ppERK/totERK levels reveals a statistically significant increase in ppERK/totERK levels in the socially enriched <i>Cs</i> flies (p = 0.0002) with no statistical increase in ppERK/totERK levels in either <i>rl</i>¹ or <i>rut</i>²⁰⁸⁰ mutant flies (p = 0.113 and p = 0.579, respectively, student’s t-test, * = p < 0.05). <i>C</i>, Immunohistochemistry for PDF in brains of <i>Cs</i>, <i>rl</i>¹ and <i>rut</i>²⁰⁸⁰ flies exposed to social enrichment and social isolation. <i>D</i>, Quantification of PDF-positive terminals from brains in <b><i>C</i></b>. PDF terminals are increased following exposure to social enrichment in <i>Cs</i> flies p = 0.043, but not in <i>rl</i>¹ and <i>rut</i>²⁰⁸⁰ flies, <i>p</i> = 0.259 and p = 0.666, respectively, student’s t-test; n=11-15/group Values normalized to the isolated siblings.