Puromycin and Retention in the Goldfish

Abstract

A first experiment compared the behavior of goldfish injected with puromycin immediately after each of a weekly series of brief discriminative training sessions in the shuttlebox to that of appropriate controls. Discrimination was not prevented, nor was escape from shock impaired, but probability of response to the conditioned stimuli, both positive and negative, was reduced substantially. These results suggest that puromycin interferes with the consolidation of conditioned fear. The null outcome of a second experiment, in which all training was given in a single long session instead of a series of short sessions, suggests (contrary to recent indications) that consolidation begins in the training session. The conditioned-fear hypothesis is supported by the results of a third experiment in which the animals were shocked upon entering a goalbox to which they had previously learned to swim for food; animals injected with puromycin, immediately after the shock, entered the goalbox more readily 1 week later than did appropriate controls.

The effect of puromycin on retention of conditioned cardiac deceleration in the goldfish

“…Since puromycin did not block retention of conditioned cardiac deceleration under the conditions of our experiment, the results may be at variance with the interpretation of Potts and Bitterman (1967) that puromycin produces amnesia in the goldfish via a block of conditioned fear. The effect of puromycin in their experiments may, therefore, be more readily interpreted to indicate that puromycin disrupts some more complex aspect of behavior and that the lower rate of response to both the negative and positive stimuli in their experiments may indicate a partial failure of the fish to acquire the learned response.…”

“…Since fish injected prior to training can acquire the avoidance response, we have assumed that these agents affect retention by blocking the formation of "permanent," or long-term memory, but not short-term memory. Potts and Bitterman (1967) found that postsession injections of puromycin produced marked retention deficits in goldfish in a discriminative shuttlebox avoidance task as well as in a passive goal box avoidance task. In the shuttlebox, fish treated previously with puromycin had low responding levels and showed poor discrimination of positive and negative cue lights.…”

The Biochemical Basis of Long-Term Memory

“…(10a) Slightly different experimental conditions gave somewhat different results. Potts & Bitterman (1967) report continued improvement in the performance of goldfish given weekly training sessions, each one followed immediately by injection of puromycin. They did cause some impairment but not the complete lack of improvement that might have been expected from the results of Agranoff et al (Agranoff & Klinger, 1964;Agranoff et al 1965Agranoff et al , 1966Agranoff et al , 1967Brink et al 1966;Agranoff, 1967).…”

Protein Synthesis and Memory

“…The effect of puromycin in the goldfish was confirmed by Potts and Bitterman (1967). These authors emphasized the fact that puromycin seems to sup press specifically conditioned fear; in an experiment with positive reinforcement, puromycin was without effect.…”