Pharmacological Conditioning Research Articles

Undrugged rotational response in nigro-striatal system-lesioned rats is related to the previous early response to apomorphine when repeatedly administered

Development and time-course characteristics of undrugged rotational response weeks or months after repeated apomorphine administration in 6-hydroxydopamine-lesioned rats (1) were explored. In one series of experiments, all groups recieved several drug doses two-three weeks post-lesion and remained undrugged at different intervals from the last drug injection. Weeks or months later, they were injected with saline in the same environment where they previously had recieved apomorphine. In this way we studied acquisition, time-course and extinction of the rotational response after saline. Furthermore, we related this undrugged response which does not fully develop until two weeks after treatment (2), and which previously had not been related to a specific parameter of the rotational response to the drug, to a critical point of the time-course response to the drug, i.e., the early rotational response in the first minute after injection. This earlu response is a learning phenomenon based on the environmental cues where drug has been repeatedly administered. Finally, we state the concept of pharmacological conditioning using this animal model of Parkinson's disease, in agreement with our own results and the previous results of Silverman and Ho (1981).

Effect of pharmacologic conditioning on sulfadiazine toxicity and concentrations in plasma.

In female rats, pretreatment with pregnenolone-16α-carbonitrile (PCN), spironolactone or CS-11 reduced the toxicity of sulfadiazine; the first two steroids also decreased its concentrations