Reversal of the reserpine-induced suppression of the conditioned avoidance response in the cat byl-DOPA

✍ Scribed by Lewis S. Seiden; Lennart C. F. Hanson

• Publisher: Springer
• Year: 1964
• Tongue: English
• Weight: 350 KB
• Volume: 6
• Category: Article
• ISSN: 0033-3158
• DOI: 10.1007/bf00413153

✦ Synopsis

It has been demonstrated that 3,4-dihydroxyphenylalanine (DOPA) can temporarily counteract the reserpine-induced suppression of motor activity (CA~LSSO~ et al. 1957; BLASCttKO and CRVSCIEL 1960; SMITE and DEWS 1962). Both BEnTLE~ and I~OSENG~E~ (1959a), and EVERETT and WIEGAND (1962) have demonstrated that this antagonism coincides with the accumulation of 3,4-dihydroxyphenylethylamine (dopamine, DA) in brain. Moreover it has been found that L-DOPA can temporarily and partially antagonize the reserpine-induced suppression of a conditioned avoidance response, (CAI~) in mice and rats. The injection of L-DOPA also produced an increase in brain and heart of DA when administered to mice pretreated with reserpine, but the levels of noradrenaline (NA) remained unaffected (SEm) EN and CA~LSSON 1963, 1964). The increase in DA corresponded to the L-DOPA-effeet on the CAR in that both were temporary, and they both followed approximately the same time course, indicating that the effect was mediated by the DA formed from its administered precursor. The present study was designed to investigate the effect of L-DOPA on the reserpine-induced suppression of the CAI~ in an other species, namely the cat, and also to measure the alterations of brain catecholamines in various areas following the administration of these drugs.

Methods

Behavioural

Ten mature cats, four males and six females, weighing 2.2--4.5 kg, were trained to at least 90 ~ CAI~ (eight of them in fact were overtrained and reacted 100~ CAI~) in ~ shuttle box with an electrified grid floor. The shuttle box was divided by a hurdle--20 cm high--in two compartments, each of which measured 47 • 58 • 56 cm (h • b • l).