Blockade of adenosine A1 receptors in the posterior cingulate cortex facilitates memory in rats.
Male Wistar rats were bilaterally implanted with indwelling cannulae in the caudal region of the posterior cingulate cortex. After recovery, animals were trained in a step-down inhibitory avoidance task (3.0-s, 0.4-mA foot shock) and received, immediately after training, a 0.5-microl infusion of the adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA; 1, 50 or 100 nM) or of the adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 1, 25 or 50 nM). Animals were tested twice, 1.5 h and, again, 24 h after training, in order to examine the effects of these agents on short- and long-term memory, respectively. Only 50-nM DPCPX was effective in altering memory, promoting a facilitation. These results suggest that adenosine A1 receptors in the posterior cingulate cortex inhibit memory consolidation in a way that their blockade facilitates memory for inhibitory avoidance in rats.
Pereira
Grace S
GS
Laboratório de Enzimologia e Centro de Memória, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Mello e Souza
Tadeu
T
Vinadé
Elsa R C
ER
Choi
Humberto
H
Rodrigues
Cristina
C
Battastini
Ana M O
AM
Izquierdo
Iván
I
Sarkis
João J F
JJ
Bonan
Carla D
CD
D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006179:Gyrus Cinguli / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008568:Memory / Q000187:drug effects*; D058915:Purinergic P1 Receptor Antagonists; D051381:Rats; D018047:Receptors, Purinergic P1 / Q000502:physiology; D012153:Retention, Psychology / Q000187:drug effects; D014970:Xanthines / Q000494:pharmacology*
D058915:Purinergic P1 Receptor Antagonists; D018047:Receptors, Purinergic P1; D014970:Xanthines; C048599:N(6)-cyclopentyladenosine; C051360:1,3-dipropyl-8-cyclopentylxanthine; D000241:Adenosine