Tiger salamanders’ (Ambystoma tigrinum) response retention and usage of visual cues following brumation

Abstract

Brumation enables tiger salamanders (Ambystoma tigrinum) to survive changes in temperature. However, it is unclear how this affects memory retention. We explored how brumation impacted salamanders’ retention of a learned response to a visual cue through two experiments. We hypothesized salamanders would retain information across this state. However, we also hypothesized that retention could be manipulated through cold temperature exposure timing. We hypothesized that cold temperature exposure immediately after reactivation of a memory would decrease retention of that memory following brumation. Our results indicate that salamanders can respond utilizing visual cues and that performance can be retained across this state. However, our results also indicate that if exposure to cold temperatures occurs directly following a recall experience, memory for the information that was recalled just prior to cold temperature exposure can be disrupted. This suggests that the timing of the recalling of information and the exposure to the cold temperatures inherent to brumation is important to memory retention through this state. Future studies should investigate the impact of the timing of extreme temperature exposure on retention over other torpor states, including hibernation and aestivation. Additionally, the mechanism underlying such impaired retention should be explored.