ABSTRACT
Individual characteristics of the nervous system become apparent in individual behaviour (IB). Investigation of IB of animals reveals not only individual phenomenology but also the mechanisms underlying IB. Elucidation of molecular mechanisms participating in the formation of IB is important both for basic neurobiology and for applied science. Since rodents are used in most studies, one of the problems related to IB is the search of approaches and methods for evaluating the main parameters which characterize the rodent nervous system. The “open field” test is widely used as a method of evaluating spontaneous rodent behaviour, based on the exploratory component of behaviour (Bures et al., 1983; Markel, 1981). In this test, levels of locomotor activity (both horizontal and vertical) and of emotionality appear to reflect the functional state of different parts of the nervous system, and to be closely related to other forms of behavior, learning, and memory. Emotionality in this test is evaluated as elements of vegetative activity (defecation, urination), and forms of displacement activity. However, the evaluation of emotionality in the “open field” test is quite difficult because neither the number of defecations and urinations nor motor activity are adequate indices of the emotional status of rodents. The level of motor activity is sometimes used as an index of emotionality, but sometimes results in opposite interpretations of similar data obtained by different authors. D.Kulagin (1975) revealed inverse correlations of locomotor activity with the force of excitatory processes, as well as of emotionality with the average index of conditioning. Whereas this author demonstrated a positive correlation between the locomotor
activity and the conditioning rate, G.Chaichenko (1982) revealed a negative correlation between these parameters.
