Fig. 6.

NGF-induced activation of TrkA/TrkB fusion receptors in cultured hippocampal neurons. The indicated construct was overexpressed using a Sindbis virus expression system as described in Fig. 5. Two days after virus infection, cells were cultured in serum-free Neurobasal medium for 12 h and then treated with NGF (100 ng/ml) or BDNF (100 ng/ml) for 5 min. Cell lysates were collected for immunoblotting with the indicated antibodies. The activation and expression of TrkA/TrkB chimeric receptors were studied using antibodies specific for phospho-Tyr490 (upper arrow) and the EC domain of TrkA receptor (lower arrow), respectively. Bars on the left indicate the location of molecular size markers indicating 175 kDa (upper) and 83 kDa (lower)