T. Charekishvili, T. Nekashvili, T. Shetekauri, N. Tsertsvadze, T. Oniani, N. Oniani
Ilia State University, Tbilisi, Georgia
Institute “Tengiz Oniani Laboratory of Sleep-Wakefulness Cycle Studies”
The main characteristic of adaptive fear is to avoid aversive stimuli or situations. Active avoidance (AA) learning is an experimental defensive behavior that prevents aversive stimuli. Also, the study of memory consolidation during active avoidance task learning has always been a subject of interest.
The aim of the present study was to determine the role of an increased interval between trials and as well sleep deprivation on implicit memory processing in an incompletely learned AA task.
The testing subjects were inbred albino, adult, laboratory rats both male and female. In experiments, as a control we used a two-way AA task, where the number of the trials was equal to 25 and the duration of the intertrial interval (ITI) was equal to 1 min. To test the learning level of the AA task, we reused the same AA procedure. The test was carried out 0 and 24 hours after the initial training. If necessary, we used the method of “gentle handling ” for total sleep deprivation.
The data obtained indicate that with an increase in the duration of the ITI to 2.5 and 5 minutes, the degree of learning of the AA task does not change. On the other hand, with an increase in the ITI up to 10 min significantly worsened the performance of the task by the animals. In this series of experiments, in the intervals between trials, the rats were not disturbed and could sleep. The value of the degree of task learning when checking immediately after the experiment was also low. It increased significantly when tested after a 24 hour period.
Under the same conditions, total sleep deprivation for 10 minute ITI improves task performance in animals and the degree of the AA task learning increases. When tested, it does not statistically differ from the control values.
It can be assumed that during the prolonged task of AA learning, processes are initiated that are similar in nature to the processes occurring during the Kamin effect. These processes probably determine the formation of implicit memory in animals. In favor of this assumption is the fact that after a 24 hour period the degree of task learning does not differ from the control value.