The "campus syndrome" in pigs: neurological, neurophysiological, and neuropharmacological characterization of a new genetic animal model of high-frequency tremor.

Inherited neurological diseases in animals are of interest to a wide range of scientific disciplines, particularly because such animals may be suited as genetic animal models for respective human disorders. Because the pig has a number of anatomic and physiologic features similar to those of human beings, this species is becoming increasingly popular in biomedical research. The usefulness of pigs as genetic models of neurological diseases is illustrated by the porcine model of malignant hyperthermia (MH), i.e., a frequently fatal myopathic disease in both pigs and humans. In the present study, we describe a new hereditary movement disorder in Pietrain pigs, which may represent a useful genetic animal model of high-frequency tremor. Because the disorder was first detected in the offspring of a boar named "Campus," we use the term "Campus syndrome" in this respect. Segregation analysis of breeding studies indicates that the syndrome is inherited as a monogenic dominant trait. DNA-based testing of the mutation involved in MH myopathy showed that expression of the Campus syndrome in pigs is not dependent on homozygosity for the MH mutation. In affected pigs, the Campus syndrome develops at an average age of 27 days. The syndrome is characterized by muscular weakness and a very intense tremor of the legs when standing and walking but not when at rest in a lying position. The intensity of tremor and muscular weakness progressively increases with age, resulting in pronounced postural instability. Despite these neurological abnormalities, body weight gain in affected pigs does not differ from that in unaffected siblings.(ABSTRACT TRUNCATED AT 250 WORDS)