Behavioural effects of a prolonged treatment with small doses of morphine in cats

✍ Scribed by B. Djahanguiri; M. Richelle; O. Fontaine

• Publisher: Springer
• Year: 1966
• Tongue: English
• Weight: 460 KB
• Volume: 9
• Category: Article
• ISSN: 0033-3158
• DOI: 10.1007/bf00406447

✦ Synopsis

The present experiment was designed to answer the following questions: Using an operant conditioning situation, will it be possible to detect behavioral effects of doses of morphine corresponding to human clinical doses? How will these effects, if any, develop with repeated administration? Is operant bchaviour a sensitive measure of withdrawal reactions ?

Methods

Subjects. Subjects were three eats, weighing about 2.5 kg, numbered 10 (male), ll (male) and 12 (female). They were from the same litter, born in the laboratory and approximately 18 months old when the experiment was started. They lived in the animal room in large home cages (180•215 em). Cats 10 and 11 were housed together; 12 was alone. They had not been used as subjects in pharmacological experiments before, but had worked in the operant conditioning situation since the age of 10 months. They were fed with the milk obtained as reinforcement dm'ing the experimental sessions (or an equivalent amount, 75 ml, given in the home cage when no experiment was run), plus 50 g of boiled meat per day.

Apparatus.

A home-made Skinner-box was used, equipped with a response lever (telegraph-key) and a tray. Milk was delivered into the tray through a solenoid vMve. The experimental operations were automatically controlled. The experimental events were recorded on a Gerbrands cumulative recorder and on a series of digital counters. The experimental cage was isolated, in a separate rooom, from the auditory signals of the control units. Schedule o/rein/orcement. The schedule of reinforcement was a fixed Interval 2 min (FI 2). The distribution of responses in the interval was * Belgian Government UNESCO Fellowship. Now at the Pharmacology Department, Teheran ~edieal School, Iran.

Psychopharmacologia (Berl.), Bd. 9 25