Blockade of adenosine A2A receptors reverses short-term social memory impairments in spontaneously hypertensive rats.
Spontaneously hypertensive rats (SHR) exhibit impairment across several cognitive domains such as attention, short-term memory and spatial reference memory. These cognitive deficits have been variously attributed to disrupted dopaminergic, cholinergic and adenosinergic neurotransmitter function. However, social memory in SHR has not been investigated. In the present study, we therefore evaluated whether SHR exhibit altered short-term social memory abilities compared to normotensive Wistar rats (WIS) through two experimental paradigms (social recognition and habituation-dishabituation tests). We also compared the performance of SHR and WIS rats in the object recognition test. SHR exhibited significantly impaired performance in both models of social memory, but not in the object recognition test, demonstrating a selective deficit in the ability to recognize a juvenile rat after a short period of time. The administration of acute doses of the non-selective adenosine receptor antagonist caffeine (3.0 or 10.0 mg/kg, i.p.) and the adenosine A2A receptor antagonist 4-(2-[7-amino-2-[2-furyl][1,2,4]triazolo-[2,3-a][1,3,5]triazin-5-yl-amino]ethyl) phenol (ZM241385, 0.5 or 1.0 mg/kg, i.p.) but not the adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 1.0 or 3.0 mg/kg, i.p.) reversed this social memory impairment in SHR, but these treatments did not alter the hypertension state. These results demonstrate an impairment of short-term social memory in SHR and the involvement of the adenosine A2A receptors in this alteration.
Prediger
Rui D S
RD
Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, UFSC, Campus Trindade, 88049-900 Florianópolis, SC, Brazil.
Fernandes
Daniel
D
Takahashi
Reinaldo N
RN
D058917:Adenosine A2 Receptor Antagonists; D000704:Analysis of Variance; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D004193:Discrimination Learning / Q000187:drug effects; D006185:Habituation, Psychophysiologic / Q000187:drug effects*; D008297:Male; D008569:Memory Disorders / Q000188:drug therapy* / Q000503:physiopathology; D008570:Memory, Short-Term / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D043705:Receptor, Adenosine A2A / Q000378:metabolism; D021641:Recognition, Psychology / Q000187:drug effects*; D012903:Smell / Q000187:drug effects; D012919:Social Behavior; D012931:Social Environment; D013045:Species Specificity; D014227:Triazines / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology
D058917:Adenosine A2 Receptor Antagonists; D043705:Receptor, Adenosine A2A; D014227:Triazines; D014230:Triazoles; D014970:Xanthines; C097270:ZM 241385; D002110:Caffeine; C051360:1,3-dipropyl-8-cyclopentylxanthine