Temporary and partial antagonism byl-DOPA of reserpine-induced suppression of a conditioned avoidance response

✍ Scribed by Lewis S. Seiden; Arvid Carlsson

• Publisher: Springer
• Year: 1963
• Tongue: English
• Weight: 354 KB
• Volume: 4
• Category: Article
• ISSN: 0033-3158
• DOI: 10.1007/bf00403346

✦ Synopsis

A single injection of reserpine causes depletion of 5-hydroxytryptamine and the catechol amines in brain and other tissues where these amines occur (SHowy., SILVEr, and BI~ODIE 1955, CARLSSO~ et al. 1957 a) and causes sedation and ptosis as well as other disturbances of the autonomic nervous system. CAI~LSSO~ et al. (1957b) have shown that L-3,4-dihydroxyphenylalanine (L-DOPA), the metabolic precursor of dopamine, noradrenaline, and adrenaline, is able to reverse the reserpine-induced sedation and ptosis in rabbits and mice. BLASCHKO and CH~U~ClEL (1960) have shown that DOPA is able to antagonize the locomotor suppressant effect of reserpine in mice treated with a monoamine oxidase inhibitor, and S~ITH and DEWS (1962) have made a similar observation without the use of a monoamine oxidase inhibitor.

Reserpine also interferes with the maintenance of a conditioned avoidance response (CAR) (JoH~ and KILLAlVi 1959). GE~OVESE and Gonnwu~M (1958) attempted to prevent the suppression of the CAt~ by injecting DL-DOPA (in doses up to 750 mg/kg) 30 rain prior to reserpine, and obtained negative results. Since reserpine and DL-DOPA require different times for peak action, the timing of the injections is of importance. In the present experiment it will be shown that the reserpine-induced suppression of the CAR can be partially and temporarily reversed by L-DOPA administered subsequent to reserpine.

Methods

Ten female white mice 1 weighing between 20 and 30 grams and ten male hooded rats ~ weighing between 250 and 300 grams were used in the experiment.