How Opiates Change Behavior

Nichols, John R.

doi:10.1038/scientificamerican0265-80

Cited by 71 publications

(26 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Inspection of Table 1 indicated a severe and immediate drop in morphine intake for both groups. This immediate drop is quite different from the gradual decrease in morphine consumption which is generally reported (Nichols et aI, 1956;Nichols, 1965). During the pre-irradiation period, the absolute mg/ kg morphine intake was twice as great for Group 1 as that for Group 2, although the MI scores for both groups are quite similar.…”

Section: Results An-d Discussidncontrasting

confidence: 44%

“…The rat then displays opiate directed behavior in a two choice situation. The "trained" preference (morphine solution) gradually reverts to the natural choice of tap water as a function of time; this phenomenon is represented by gradual decrease in morphine consumption over a period of weeks (Nichols et al, 1956;Nichols, 1965). It appeared to be of interest to investigate the modification of opiate directed behavior (which represents a physiological dependency) by avoidance conditioning techniques.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Radiation produced avoidance to morphine

Mountjoy

Roberts

1967

Psychon Sci

View full text Add to dashboard Cite

The effects of two concentrations of morphine solution (eS) Radiation has been demonstrated to function as an unconditioned aversive stimulus (UCS) for avoidance conditioning (GarCia et al, 1955). Although saccharin solution has been used as the conditioned stimulus (CS) in many studies, avoidance conditioning has been obtained utilizing chocolate milk (Kimeldorf et al, 1960) and alcohol (Peacock & Watson, 1964).The above studies produced conditioned avoidance behavior to "naturally" preferred solutions. Given a choice between tap water and morphine solutions, tap water will be the "natural" choice displayed by rats. A technique has been developed (Nichols et aI, 1956) which will train rats to choose morphine solution. The rat then displays opiate directed behavior in a two choice situation. The "trained" preference (morphine solution) gradually reverts to the natural choice of tap water as a function of time; this phenomenon is represented by gradual decrease in morphine consumption over a period of weeks (Nichols et al, 1956;Nichols, 1965). It appeared to be of interest to investigate the modification of opiate directed behavior (which represents a physiological dependency) by avoidance conditioning techniques. Method and ProcedureThe Ss were 18 male Sprague-Dawley rats from the Western Michigan University colony, approximately six months old, with a mean weight of 305. g at the beginning of experimentation.Pre-Irradiation. Morphine dosage began at 9 mg/ kg/day and was increased by 1/2 of the dose of the previous day until 40 mg/kg/day was reached. Increases of 10 mg/kg/day were made until Ss were receiving 110 mg/kg/day, then by 20 mg/kg/day until a level of 210 mg/kg/day was reached. Subcutaneous injections of morphine sulphate were scheduled at 12 h intervals, 9:00 AM and 9:00 PM. The site of injections was alternated between the left and right sides. During the injection series. Ss received tap water for 1 h during every 24 h period, 6 h after the morning injection to avoid association of water availability with the injection of morphine. Wayne Lab Blocks were available at all times. Following cessation of injections, Sa were offered morphine in tap water (0.5 mg/cc) for oral intake in a forced Ten Ss continued to refuse to drink. When no measurable amount of morphine solution had been ingested for seven days, tap water was made continually avallable, but the Ss still did not drink. Using preinjection weight as a base, these Ss had lost 42-45% of their body weight at the time of death. Group 1 was composed of those four Ss which drank a 0.5 mg/cc morphine solution. Group 2 of those four Ss which drank a 0.25 mg/kg concentration.IrradiatIOn. In keeping with the deprivation schedule, Ss were irradiated on the day when morphine only was presented. 2 The radiation (X-radiation) source was a Mathison 140 P K V mobile therapy unit drawing 8 milliamperes and having an 8 in. cone. Exposure was checked by a CD V 746 dosimeter which gave readings in Roentgen (R) units. The radiation chamber was a circular wooden ...

show abstract

Section: Results An-d Discussidncontrasting

confidence: 44%

mentioning

confidence: 99%

Radiation produced avoidance to morphine

Mountjoy

Roberts

1967

Psychon Sci

View full text Add to dashboard Cite

show abstract

“…Drug-oriented behavior, which serves to reduce these withdrawal symptoms, is seen as a type of active avoidance. This theory is supported by experiments (Nichols, 1965) in which dependent rats are given morphine injections to reduce withdrawal symptoms. These animals tended to decrease their morphine intake significantly.…”

supporting

confidence: 55%

“…Groups ContP and ContNP were anesthetized and holes were bored in the skulls for the control operations, but no brain damage was induced. After 2 weeks of postoperative recovery, Groups CP and ContP were treated according to a modification of the technique used by Nichols (1965) to induce morphine addiction. Subcutaneous injections of morphine were given twice daily.…”

Section: Surgical Proceduresmentioning

confidence: 99%

Effects of cingulate cortex lesions and morphine premedication on morphine intake in rats

Trafton

Kahn

1974

Psychobiology

View full text Add to dashboard Cite

Groups of rats were given bilateral lesions in the cingulate cortex and then half were subjected to a regimen of chronic morphine injections, while the other half received no premedication. Morphine-oriented behavior was indexed by a learned preference for a bitter morphine HO solution. Bilateral anterior cingulate cortex lesions resulted in a decrement in the acquisition of drug-oriented behavior, while premedication produced an enhancement of morphine intake.In the search for 'an explanation of drug-oriented behavior, two main lines of argument have developed. The first postulates that the effects of the drug are pleasurable or reinforcing; thus drug intake is more likely to occur again. It has been shown, for example, that monkeys will learn to self-administer morphine before sufficient time has elapsed for dependence to develop (Deneau, Yanagita, & Seevers, 1969). The second type of hypothesis is that opiate intake, at least in dependent animals, is mainly a type of avoidance learning. It is argued that withdrawal effects in drug-deprived rats previously rendered dependent on morphine serve as noxious stimuli. Drug-oriented behavior, which serves to reduce these withdrawal symptoms, is seen as a type of active avoidance. This theory is supported by experiments (Nichols, 1965) in which dependent rats are given morphine injections to reduce withdrawal symptoms. These animals tended to decrease their morphine intake significantly.It has been shown (Fox, Kimble, & Lickey, 1964;Thomas & Slotnick, 1962;Trafton, 1967) that limbic cortex lesions produce decrements in avoidance learning, and Foltz andWhite (1957) andFoltz (1959) have shown that cingulate lesions in primates modify withdrawal behavior. Trafton and Marques (1971) have shown that cingulate cortex lesions also produce decrements in morphine-oriented behavior in rats. They argue that since lesions producing avoidance learning deficits also produce decrements in morphine intake by dependent rats, the avoidance model of opiate intake is, at least partially, supported.The present study was designated to examine further the effects of cingulate lesions on morphine-oriented behavior in rats. Theoretically, if cingulate lesions produce decrements in avoidance learning, and if this inability to respond to noxious stimuli (withdrawal symptoms) accounts for decrements in morphine intake (Trafton & Marques, 1971), then such decrements should only be seen in drug-dependent rats. Animals that 26are not dependent on opiate drugs should show normal morphine intake patterns. However, if nondependent rats also show morphine intake decrements follOWing cingulate lesions, the effect may be due to the effect of the lesions on positive reinforcement or on other aspects of morphine intake, since withdrawal symptoms should be nonexistent. EXPERIMENT I Method SubjectsThirty-five naive Sprague-Dawley male albino rats, weighing from 297 to 438 g, served as Ss. The rats were individually housed in wire cages with food (Purina Rat Chow) freely available throughout the experiment. ...

show abstract

“…Nichols has used his results to support a drive-reduction explanation of opiate abuse in humans and animals (Nichols, 1965). This explanation assurnes that the drive state caused when physically dependent Ss are deprived of opiates is reduced by an opiate injection, and that the drive reduction reinforces the behavior preceding it.…”

mentioning

confidence: 91%

Imparting reinforcing property to the taste of morphine through morphine injections

Coussens

1972

Psychon Sci

View full text Add to dashboard Cite

The present experiment tested the hypothesis that the taste of morphine would become a secondary reinforcer for rats made physically dependent on morphine by large, rapid intravenous injections. Rats made dependent by such injections and then withdrawn licked a dilute morphine solution more during a 30-sec licking period than did nondependent rats. A second experiment indicated that rats made physically dependent on morphine by 8 days of rapid injections licked a morphine solution more during withdrawal than did rats made dependent by 8 days of slow infusions. The results supported the preliminary hypo thesis.

show abstract

How Opiates Change Behavior

Cited by 71 publications

References 0 publications

Radiation produced avoidance to morphine

Radiation produced avoidance to morphine

Effects of cingulate cortex lesions and morphine premedication on morphine intake in rats

Imparting reinforcing property to the taste of morphine through morphine injections

Contact Info

Product

Resources

About