Masking in waved-2 mice:: EGF receptor control of locomotion questioned

It has been suggested that epidermal growth factors (EGF) are responsible for the inhibition of locomotion by light ( i.e. , masking) in nocturnal rodents (Kramer et al., 2001). The poor masking response of waved-2 (Egfr(wa2) ) mutant mice, with reduced EGF receptor activity, was adduced in support of this idea. In the present work, we studied the responses to light over a large range in illumination levels, in a variety of tests, with pulses of light and with ultradian light-dark cycles in Egfr(wa2) mutant mice. No evidence suggested that normal functioning of epidermal growth factor receptors was required, or even involved, in masking.