SRF-VP16 enhances survival of facial motorneurons. (A) (left) The facial nerve is outlined in blue. (right) Virus injection (green) and position of axotomy is depicted (arrow). Pictures in (B-G) were taken from the facial nucleus whose position is indicated by the red circle. Facial motorneurons express either SRF-VP16 or SRF-ΔMADS-VP16 along with GFP, whose expression is depicted in (B-G). (B, C) Facial nuclei of an SRF-ΔMADS-VP16 (B) or SRF-VP16 (C) expressing animal taken at 5 days post infection (d.p.i.) and lesion. No obvious differences were discernable. (D-G) The facial nucleus of an SRF-ΔMADS-VP16 (D, F) or SRF-VP16 (E, G) infected animal at 25 d.p.i/lesion. In SRF-ΔMADS-VP16 (D, F) compared to SRF-VP16 (E, G) numbers of surviving neurons are reduced. SRF-ΔMADS-VP16 expressing neurons are atrophic and assume a “bleb-like” morphology without innervation (see insert in D). SRF-VP16 neurons protrude neurites and cell bodies are squared in shape (insert in E). (H) Numbers of GFP-positive neurons/section are indicated. (I) At 25 d.p.i., but not 5 d.p.i. SRF-ΔMADS-VP16, in contrast to SRF-VP16 expressing neurons were degenerated. Dashed lines depict outlines of the facial nuclei. Scale-bar (B-G) = 100 μm; inserts = 10 μm.