A study of the role of noradrenaline in behavioural changes produced in the rat by psychotomimetic drugs
British Journal of Pharmacology February 1, 1969 DOI: 10.1111/j.1476-5381.1969.tb07983.x via OpenAlex
Summary
AI-generated from the abstractThree psychoactive drugs—LSD-25, psilocybin, and JB-329—reduced noradrenaline levels in the rat hypothalamus. They also affected how quickly rats learned a conditioned avoidance response: LSD-25 and psilocybin slowed learning, while JB-329 sped it up. For LSD-25 and psilocybin, doses that altered learning were lower than those needed to lower hypothalamic noradrenaline, and the peak effect on learning occurred about 1.5 hours after injection, compared to 3 hours for noradrenaline content. The dose causing gross behavioral excitation matched the dose that depleted noradrenaline. Pretreatment with reserpine or α-MT did not change the intensity of excitation from LSD-25 or psilocybin but shortened its duration; JB-329's excitation was abolished by reserpine and reduced by α-MT.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Rats |
| Interventions | psilocybin reserpine |
| Topics | Psilocybin |
| Keywords | Reserpine Psychotomimetic Hallucinogen Avoidance response |
| Citations | 40 |
| Key finding | LSD-25, psilocybin, and JB-329 reduce hypothalamic noradrenaline and alter conditioned avoidance response acquisition, with LSD-25 and psilocybin retarding and JB-329 enhancing it, and the drugs' behavioral and neurochemical effects show different time courses and dose thresholds. |
Abstract
LSD‐25, psilocybin and JB‐329 reduced the noradrenaline content of the rat hypothalamus. All three drugs affected the acquisition of a conditioned avoidance response, LSD‐25 and psilocybin retarding and JB‐329 enhancing the acquisition. With the exception of JB‐329, doses affecting the acquisition of a conditioned avoidance response were lower than those required to decide hypothalamic noradrenaline concentrations. The time of peak drug effect on the acquisition of a conditioned avoidance response occurred approximately 1.5 hr after injection as opposed to 3 hr in the case of noradrenaline content. The amount of LSD‐25, psilocybin and JB‐329 necessary to elicit gross behavioural excitation was similar to the dose producing noradrenaline depletion. Here also the peak behavioural effect was detected earlier. Pretreatment with reserpine and α‐MT had no effect on the intensity of gross behavioural excitation induced by LSD‐25 and psilocybin but shortened the duration of the response. The excitation induced by JB‐329 was abolished by reserpine pretreatment and was markedly reduced both in intensity and duration by the prior injection of α‐MT.