Macromolecules and behavior II. Training induced alteration in leucine transfer RNA of goldfish brain

Goldfish were trained to swim upright after a polystyrene float had been attached ventrally. The effects of training on the amino acid acceptor activity and methylated albumin-kieselguhr column chromatography profile of several brain isoaccepting tRNA species were studied. Comparison of the kinetics of aminoacylation and chromatography profile of tRNAs from trained and control fish showed no differences for Arginyl-, glutamyl-, histidyl-, lysyl-, phenylalanyl-, seryl, threonyl- or valyl-tRNA. In contrast, training induced alterations in tRNA-Leu activity and activity profile. Training had no effect on brain amino acid pools or liver tRNA-Leu activity. Together, behavioral control experiments and plasma cortisol titers indicated that the training-induced increase in tRNA-Leu activity was not caused by stress, exertion, random disoriented swimming or the minor surgical procedures required. Rather, this activity change seems to correlate with some, as yet unidentified, aspect of behavioral training. The implications of these findings with respect to learning are discussed.