Intra-hippocampal microinjections of anisomycin did not block glucocorticoid-induced impairment of memory retrieval in rats: an evidence for non-genomic effects of glucocorticoids.
Previous findings indicated that intra-cerebral as well as systemic injections of glucocorticoid hormones shortly before retention testing induce impairment of long-term memory retrieval, but the underlying mechanisms (genomic or non-genomic) are not known. To clarify this issue, we investigated the involvement of protein synthesis in the hippocampus in glucocorticoid-induced impairment of memory retrieval. Young rats carrying bilateral cannulae aimed at the hippocampus were trained in a water maze (MWM) task with six trials per day for six consecutive days. Retention of the spatial training was assessed 24h after the last training session with a 60-s probe trial. Corticosterone (1mg/kg) was injected 30 min before retention testing with or without prior bilateral intra-hippocampal injections of anisomycin (80 or 160 microg/mul per site) as an inhibitor of protein synthesis. The control animals received vehicle or saline solutions. The results show that corticosterone-induced impairment of memory retrieval was not blocked by intra-hippocampal infusions of anisomycin. Our data suggest that corticosterone influences memory retrieval via a protein independent mechanism and provide evidence for rapid actions (non-genomic) of glucocorticoids on memory retrieval.
Sajadi
Ahmad Ali
AA
Laboratory of Learning and Memory, Physiological Research Center, Semnan University of Medical Sciences, P.O. Box 35195-163, Semnan, Iran.
Samaei
Syed Afshin
SA
Rashidy-Pour
Ali
A
D000704:Analysis of Variance; D000818:Animals; D000841:Anisomycin / Q000008:administration & dosage*; D003345:Corticosterone / Q000008:administration & dosage*; D005938:Glucocorticoids / Q000008:administration & dosage; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D008568:Memory / Q000187:drug effects*; D008845:Microinjections; D011500:Protein Synthesis Inhibitors / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar
D005938:Glucocorticoids; D011500:Protein Synthesis Inhibitors; D000841:Anisomycin; D003345:Corticosterone