Limits...
Protein synthesis and degradation are required for the incorporation of modified information into the pre-existing object-location memory.

Choi JH, Kim JE, Kaang BK - Mol Brain (2010)

Bottom Line: In this study, we utilized an object rearrangement task, in which partial information related to a pre-existing memory is changed, promoting memory modification.Inhibitors of both protein synthesis and protein degradation impaired adequate incorporation of the altered information, each in a distinctive way.These results indicate that protein synthesis and degradation play key roles in memory modification.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Creative Research Initiative Center for Memory, Department of Biological Sciences, College of Natural Sciences, Seoul National University, 151-742 Seoul, Korea.

ABSTRACT
Although some reports indicate that protein synthesis dependent process may be induced by updating information, the role of protein synthesis and degradation in changing the content of pre-existing memory is yet unclear. In this study, we utilized an object rearrangement task, in which partial information related to a pre-existing memory is changed, promoting memory modification. Inhibitors of both protein synthesis and protein degradation impaired adequate incorporation of the altered information, each in a distinctive way. These results indicate that protein synthesis and degradation play key roles in memory modification.

Show MeSH
Object rearrangement task. A, Schematic view of the task. After five days of habituation to the context, the mice were exposed to four distinctive objects each placed in one of the four positions for 15 minutes (Day 1). Two adjacent objects' positions were switched for the next two days (Day 2, Day 3), exposed for 15 minutes each. The object pair that is switched was counterbalanced between experiments. B, Preference to unswitched and switched objects over 3 days (n = 6, *p < 0.05; paired t test). Preference is the percentage of the two switched/unswitched objects exploration time from the total exploration time. C, Preference to each objects in the first day (n.s., non significant).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2823727&req=5

Figure 1: Object rearrangement task. A, Schematic view of the task. After five days of habituation to the context, the mice were exposed to four distinctive objects each placed in one of the four positions for 15 minutes (Day 1). Two adjacent objects' positions were switched for the next two days (Day 2, Day 3), exposed for 15 minutes each. The object pair that is switched was counterbalanced between experiments. B, Preference to unswitched and switched objects over 3 days (n = 6, *p < 0.05; paired t test). Preference is the percentage of the two switched/unswitched objects exploration time from the total exploration time. C, Preference to each objects in the first day (n.s., non significant).

Mentions: To assess the incorporation of changed information into the preexisting memory, we chose an object-location memory task [11]. This task measures object-location associative memory utilizing the innate tendency of rodents to explore the novel aspects of the environment. The scheme of the task is depicted in Figure 1A. Nine- to 11-week-old C57BL/6N male mice were used for all the experiments, housed as described previously [12]. After five days of 15 minutes habituation to a context, the mouse was exposed for 15 minutes to four objects located in one of the four positions in the context. Twenty-four hours later, the mouse was re-exposed to the context for 15 minutes with the location of two adjacent objects inter-switched while the other two left unchanged. Higher explorative preference to the switched objects was expected due to the novelty of the situation. On the next day, the mouse was re-exposed for 15 minutes to the same object configuration as the second day. If it had successfully incorporated the changed information on the second day, there would be no novel aspects in each object anymore, resulting in similar preference for each of them.


Protein synthesis and degradation are required for the incorporation of modified information into the pre-existing object-location memory.

Choi JH, Kim JE, Kaang BK - Mol Brain (2010)

Object rearrangement task. A, Schematic view of the task. After five days of habituation to the context, the mice were exposed to four distinctive objects each placed in one of the four positions for 15 minutes (Day 1). Two adjacent objects' positions were switched for the next two days (Day 2, Day 3), exposed for 15 minutes each. The object pair that is switched was counterbalanced between experiments. B, Preference to unswitched and switched objects over 3 days (n = 6, *p < 0.05; paired t test). Preference is the percentage of the two switched/unswitched objects exploration time from the total exploration time. C, Preference to each objects in the first day (n.s., non significant).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2823727&req=5

Figure 1: Object rearrangement task. A, Schematic view of the task. After five days of habituation to the context, the mice were exposed to four distinctive objects each placed in one of the four positions for 15 minutes (Day 1). Two adjacent objects' positions were switched for the next two days (Day 2, Day 3), exposed for 15 minutes each. The object pair that is switched was counterbalanced between experiments. B, Preference to unswitched and switched objects over 3 days (n = 6, *p < 0.05; paired t test). Preference is the percentage of the two switched/unswitched objects exploration time from the total exploration time. C, Preference to each objects in the first day (n.s., non significant).
Mentions: To assess the incorporation of changed information into the preexisting memory, we chose an object-location memory task [11]. This task measures object-location associative memory utilizing the innate tendency of rodents to explore the novel aspects of the environment. The scheme of the task is depicted in Figure 1A. Nine- to 11-week-old C57BL/6N male mice were used for all the experiments, housed as described previously [12]. After five days of 15 minutes habituation to a context, the mouse was exposed for 15 minutes to four objects located in one of the four positions in the context. Twenty-four hours later, the mouse was re-exposed to the context for 15 minutes with the location of two adjacent objects inter-switched while the other two left unchanged. Higher explorative preference to the switched objects was expected due to the novelty of the situation. On the next day, the mouse was re-exposed for 15 minutes to the same object configuration as the second day. If it had successfully incorporated the changed information on the second day, there would be no novel aspects in each object anymore, resulting in similar preference for each of them.

Bottom Line: In this study, we utilized an object rearrangement task, in which partial information related to a pre-existing memory is changed, promoting memory modification.Inhibitors of both protein synthesis and protein degradation impaired adequate incorporation of the altered information, each in a distinctive way.These results indicate that protein synthesis and degradation play key roles in memory modification.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Creative Research Initiative Center for Memory, Department of Biological Sciences, College of Natural Sciences, Seoul National University, 151-742 Seoul, Korea.

ABSTRACT
Although some reports indicate that protein synthesis dependent process may be induced by updating information, the role of protein synthesis and degradation in changing the content of pre-existing memory is yet unclear. In this study, we utilized an object rearrangement task, in which partial information related to a pre-existing memory is changed, promoting memory modification. Inhibitors of both protein synthesis and protein degradation impaired adequate incorporation of the altered information, each in a distinctive way. These results indicate that protein synthesis and degradation play key roles in memory modification.

Show MeSH