ISSN:
1432-2072
Keywords:
Ra-octil
;
Substance P
;
Habituation
;
Inhibitory avoidance learning
;
Conditioned place preference
;
Basal forebrain
;
Rat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The aim of this study was to investigate the effects of systemically or intracerebrally administered RA-octil, a derivate of the angiotensin converting enzyme (CE)-inhibitor ramipril, on memory and reinforcement and to compare its effectiveness with that of the neurokinin substance P (SP). In the first experiment systemic post-trial application of RA-octil and SP in the rat enhanced habituation, a learning task which does not require motivational treatments. Unlike SP, injection of RA-octil did not have reinforcing effects as measured with a conditioned place preference task. In the second experiment, a facilitation of inhibitory avoidance learning was obtained by injection of RA-octil or SP unilaterally into the basal forebrain immediately after the learning trial. In contrast, a 5 h delayed injection of RA-octil had no effects on learning. The results demonstrate memory-enhancing effects of RA-octil after systemic application as well as after injection into the basal forebrain. Furthermore, the mnemogenic effects of SP after central and peripheral administration were confirmed. Since RA-octil, although being structurally closely related to CE-inhibitors, does not affect plasma CE, yet exhibits mnemogenic effects, it is possible that “cognition-enhancing” actions of CE-inhibitors are dissociable from their action within the renin-angiotensin system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02253534
