Abstract
Reports on the effects of injections of blood fractions from schizophrenic patients into rats have been contradictory. The effects of samples of fresh serum or plasma from a group of chronic male schizophrenic patients and a group of apparently normal subjects have been compared with those of saline on conditioned responses in rats. No significant differences from the pre-injection trials were found with the rat rope-climbing and the conditioned avoidance techniques after any of the injections. Compared to saline, injections of fresh serum or of plasma reduced the responding rate of rats trained on operant schedules. No statistically significant differences could be demonstrated between the effects of the samples from schizophrenic and apparently normal subjects.