Substance P, Thyrotropin-Releasing Hormone, and Serotonin Neurons Sprout in Cervical Ventral Horn of the Wobbler Mouse, a Model for Motoneuron Disease

The mutant mouse Wobbler (wr) possesses a recessively inherited degeneration of motoneurons and other neurons in the ventral horn, predominantly in the cervical spinal cord. Therefore the Wobbler mouse has been proposed as an animal model of human motoneuron disease, including amyotrophic lateral sclerosis (ALS) and familial infantile spinal muscular atrophy (ISMA). In the human motoneuron diseases as well as in Wobbler, the primary cause of the disease remains unknown. Therefore, before the laboratory experiments began, one of us (LLV) freely speculated on the possibility that substance P (SP), a neuromodulator of primary afferents in the dorsal horn, and motoneurons in the ventral horn of the mammalian spinal cord[l] possessed trophic functions that might be lacking in the Wobbler spinal cord.