Behavior of rats in the complex maze: typology of cognition activity in normal and brain-damaged animals
N. Khonicheva1, K. Nikolskaya2 and A. Osipov2
1 Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
2 Department of Higher Nervous Activity, Moscow State University, Moscow, Russia
To model human lymbic brain pathology (which is described as a defect of consciousness) in rats, we have used spatial learning (SL) in the multi-alternative maze, where we compared intact and operated groups (massive removal of brain amygdala). The behavior was registered by hand computer method (two observers) continuously during 18 sessions per day, each lasting 13 minutes. 15 "cognitive" and 24 "emotional" components were taken into consideration. SL included re-entering the maze; therefore, the number of cycles, associated with the efficacy (E) of food rewarding, was chosen as a main parameter of SL. To overcome redundancy of data, a selection of the original data was made. According to increase of E velocity, all individual variants were clustered in three different types of SL (exponential, logistic and no-developed ones). Comparison between normal types versus amygdalectomized, using own software, showed that there is a disturbance of the "emotional profile" for every type after amygdalectomy rather than the defect of SL itself. The specificity of the last was revealed only by applying information analysis, elaborated in psycholinguistics for text decoding, to our material. For us it includes transcription of all behavioral data for every session as a continuous "symbol text", when a locomotor act in the space of the maze is symbolized by some letter to differentiate semantic information. For this approach a final realization of the SL is a sequence of 14 "letters". Previous intermediate working stages may be represented as change of different letter combinations. Frequency analysis of these combinations is supposed to reflect cognitive processing. Applying information analysis allows one to reveal abnormality of cognition activity after amygdalectomy as well as discrepancy of cognition processing for above mentioned types in normal animals.