On the genetic relationships between catalepsy and pendulum movements in rats

Predispositions to pendulum movements (PMs) and catalepsy was studied in ra t strains selected for predisposition to catalepsy and for enhanced or supp ressed PMs. Positive correlation between PMs and catalepsy at earlier stage s of selection changed to negative at later stages. Based on these data, it was hypothesized that the genes that determine the predisposition to catal epsy affect the expression of the gene determining PMs in such away that di fferent PM alleles become dominant in cases of moderate and strong effects of the catalepsy genes.