Habituation of exploratory activity in rats: action of N6phenylisopropyladenosine, caffeine and their combination.
1. L-PIA (0.2 mg/kg), caffeine (15 mg/kg) and their combination were given subcutaneously to rats tested in open field. 2. The acute administration of L-PIA reduced ambulation. Caffeine alone was ineffective but increased ambulation in combination with L-PIA. These effects may have been determined by an interaction of L-PIA and caffeine on adenosine receptors. 3. Tolerance to L-PIA was observed after a chronic administration (20 days). The chronic administration of caffeine alone or in combination with L-PIA increased ambulation. 4. In the habituation test the reduction of ambulation in the 3 successive trials was increased by L-PIA. Caffeine did not antagonize the L-PIA effect and, in part, had the same effect. These results suggest that L-PIA and, in part, caffeine improve memory consolidation in open field, and do not support the notion that L-PIA and caffeine action on memory processes is due to an interference on adenosine receptors.
Molinengo
L
L
Istituto di Farmacologia e Farmacognosia, Torino, Italy.
Orsetti
M
M
Pastorello
B
B
Scordo
I
I
Ghi
P
P
D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D004338:Drug Combinations; D005106:Exploratory Behavior / Q000187:drug effects*; D006185:Habituation, Psychophysiologic / Q000187:drug effects*; D008297:Male; D010660:Phenylisopropyladenosine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D004338:Drug Combinations; D010660:Phenylisopropyladenosine; D002110:Caffeine