Chloramphenicol-induced amnesia for passive avoidance training in the day-old chick.
The antibiotic chloramphenicol, an inhibitor of mitochondrial protein synthesis, was used to investigate the time-related changes in protein synthesis following passive avoidance training in the day-old chick (white leghorn-black Australorp). Retention of memory for this simple learning task is known to be prevented by an inhibitor of cytosolic protein synthesis, anisomycin, in a biphasic manner, with the first phase of sensitivity occurring up to 90 min post-training and the second phase between 4 and 5 h post-training (Freeman, Rose, & Scholey, 1995). Birds received bilateral intracranial injections of chloramphenicol (10 microl/hemisphere of a 7.4 mM solution) at various times relative to training and were tested 24 h later. This report shows that at the second phase of anisomycin susceptibility there was a chloramphenicol-sensitive period (5 h post-training) which had an onset time less than 1 h after injection. The effect of chloramphenicol appears not to be due to the mitochondria being energetically compromised since intracranial injections of an uncoupler of mitochondrial oxidative phosphorylation, 2,4-dinitrophenol (0.1 mM), did not disrupt memory formation when injected 5 h after training, even though it did cause amnesia when injected at the earlier time point of 20 min post-training. These results are discussed in the context of what is already known about memory formation in the day-old chick.
Freeman
F M
FM
John Curtin School of Medical Research, The Australian National University, Canberra, ACT, 0200, Australia.Fiona.Freeman@anu.edu.au
Young
I G
IG
D000818:Animals; D000841:Anisomycin / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects*; D001921:Brain / Q000187:drug effects; D002645:Chickens; D002701:Chloramphenicol / Q000494:pharmacology*; D005260:Female; D007267:Injections; D008297:Male; D011939:Mental Recall / Q000187:drug effects*; D008928:Mitochondria / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D012153:Retention, Psychology / Q000187:drug effects*; D013997:Time Factors
D011500:Protein Synthesis Inhibitors; D002701:Chloramphenicol; D000841:Anisomycin