Stages of memory formation in goldfish: evidence for an environmental trigger.

Abstract

BIOCHEMISTRY: DAVIS AND AGRANOFF 555 control rats), the mean rate of the experimental group is 0.472, and the mean control rate is 0.372 (P = 0.032). For the top 50%, the mean experimental rate is 0.765, and the mean control rate is 0.606, with P = 0.0025. Response rates for expts. 1 and 2 have been summarized in our previous paper.'8 Nut-pulling response rates, in expts. 5 and 6, have a range from 0 to 3.25 responses per min, with percentages of bar-pressing activity ranging from 6 to 100% of combined responses. Response rates prior to injection tend to be 2-3 times higher than postinjection rates. In the shuttle box (expt. 7) the mean experimental response rate was 25.3 responses, and the mean control rate was 19.4 responses (within 4 see) out of 120 stimuli, with a range from 12 to 38 responses in individual rats. About 90% of these responses were made during the 2 see that the buzzer was sounding. The mean total activity rate for this experiment was 169 box-crossings for the experimental rats and 155 for the controls. While results obtained with large numbers of rats using raw score data are similar to results from corrected data, consistent results from small samples seem to require careful control for spontaneous activity levels. For example, in expt. 5, the soluble fraction with molecular weights 1000-5000 with dosages of 1.4 brains per rat (eight experimental and eight control rats) has a mean response rate of 0.394 for the experimental group, and 0.263 for the control group. This difference is only significant at P = 0.128. Mean preinjection rates were 1.03 for the experimentals and 1.17 for the controls. The regression equation computed from the control data gave a predicted response rate of 0.177 Ro + 0.055, where Ro is the preinjection rate, for each rat. This gives mean predicted scores of 0.236 for the experimental group and 0.263 for the control group, with an advantage for the experimental group's O-P scores which is significant at P = 0.002. The obscuring of marginal effects by spontaneous activity, where this has not been adqequately controlled, may account for the seemingly negative results of many attempts at replicating the work of Babich et al., which have been reported to us in private communications. It should be emphasized, however, that we have in no case succeeded in replicating the magnitude of the effect which they have obtained.

Modification of Memory Storage Processes

“…A number of recent studies have suggested, however, that this view may be oversimplified. For example, Davis and Agranoff (1966) and, more recently, Robustelli, Geller, and Jarvik (1968) have shown that susceptibility to amnesic agents is maintained if animals are kept in the training apparatus. Under such conditions the gradient of amnesia begins not with the time of training, but rather with the time of removal from the apparatus.…”

The Effect of Sublethal Concentration of Decis 2.5 Ec Pesticide on Learning and Memory Processes in Common Carp,<I> Cyprinus Carpio</I> (Actinopterygii: Cypriniformes: Cyprinidae)

“…3). Similar weakening of long-term memory was observed by Agranoff and Klinger (1964) and Davis and Agranoff (1966) in crucian carp previously exposed to puromycin (a drug inhibiting replication of viral nucleic acids and protein synthesis).…”

“…Response time in common carp of the control group and of the group exposed to deltamethrin Production of the conditioned response was performed in 20 repetitions of stimuli sequences (1st conditioning) and the experiments were repeated after 24 h (2nd conditioning) to determine the life of produced responses. The interval between learning and testing types of behaviour was in compliance with the procedure for studies performed with the use of the classical conditioning in lower vertebrates and invertebrates (Agranoff et al 1965, Davis and Agranoff 1966, McGaugh 1966, Liu and Braud l974, Sutton et al 2002.…”

Molecular approaches to learning and memory.

“…This suggests that the LTM in these fish may require a 1-h period of consolidation after training for the completion of structural change with protein synthesis. More interestingly, other findings of this experiment suggest that the neurophysiological signal to initiate the protein synthesis for memory consolidation may not be set until the fish is returned from the experimental to the home tank, or from the arousal state to the quite one [18]. How the effect of training initiates the MOLECULAR APPROACHES TO LEARNING AND MEMORY 121 protein synthesis, and what role the newly formed protein plays in the memory consolidation, are now being thoroughly investigated.…”