INDUCTION OF C-JUN IMMUNOREACTIVITY IN SPINAL-CORD AND BRAIN-STEM NEURONS IN A TRANSGENIC MOUSE MODEL FOR AMYOTROPHIC-LATERAL-SCLEROSIS

Transgenic mice carrying amyotrophic lateral sclerosis (ALS)-linked su peroxide dismutase 1 (SOD1) mutations develop a motoneuron disease res embling human ALS. c-Jun is a transcription factor frequently induced in injured neurons. In this study we have examined the distribution of c-Jun-immunoreactivity in the brainstem and spinal cord of transgenic SOD1 mice with a glycine 93 alanine (G93A) mutation. In non-transgeni c littermates c-Jun immunostaining was predominantly situated in moton eurons. The number of c-Jun immunoreactive motoneuron was reduced in S OD1(G93A) mice due to pronounced loss of motoneurons. In SOD1(G93A) mi ce, however, c-Jun-immunoreactivity was strongly induced in neurons in the intermediate zone (Rexed's laminae V-VIII and X) of the spinal co rd and throughout the brainstem reticular formation. These Endings are of interest since increased levels of c-jun also have been found in t he intermediate zone of the spinal cord of ALS patients. Thus c-Jun ma y be involved in the neurodegenerative processes both in ALS and in mo toneuron disease in SOD1(G93A) mice.