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Journal of Neurorestoratology  2018, Vol. 6 Issue (1): 93-98    doi: 10.26599/JNR.2018.9040005
Research Article     
Lateralized display of spontaneous exploratory behaviour induced by novelty in intact rats: Effects of geometrically different environments
Silvia G. Ratti, Renata G. Lario, Edgardo O. Alvarez(✉)
Laboratorio de Neuropsicofarmacología Experimental, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza 5500, Argentina
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Laterality is conceived as a functional property of the brain, where parallel neural circuits modulate complementary aspects of one function. Well known examples are handedness and speech in humans. Laterality also is present in animals indicating a general evolutionary functional aspect and not a single distinctive trait of humans. In the present work, the consistency of one lateralized response in the spontaneous behaviour of exploration, driven by novel environments with different geometrical proportions was studied in rats. Consistency of response was considered when the animal shows the same preferential display in different testing contexts. Three geometrical forms of environments (square, rectangle and T shaped environment) were presented to normal intact rats. Exploratory activity measured by a digital counting device was video-taped in a 3 min duration tests. In these environments, rats had the choice to explore the right or the left aspect of the devices. Results show that in the square box, animals showed a right-biased exploration, and show no preference in the rectangular box, and left-biased exploration in the T shaped environment. Data reveal that animals show inconsistency in the lateralized behavioural response, where the geometrical characteristics of the environment are important to display some biased response.

Key wordslaterality      exploration      novelty      geometrical environments     
Received: 29 July 2018      Published: 09 November 2018
Corresponding Authors: Edgardo O. Alvarez   
Cite this article:

Silvia G. Ratti, Renata G. Lario, Edgardo O. Alvarez. Lateralized display of spontaneous exploratory behaviour induced by novelty in intact rats: Effects of geometrically different environments. Journal of Neurorestoratology, 2018, 6: 93-98.

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Fig.?1Photography and graphical representation the geometrical environments used to test the exploration response of intact normal rats. (a) “Square”, this in fact represents a cubic box environment. (b) “Rectangle”, this in fact represents a solid rectangular box environment. (c) “T solid Rectangle”, this in fact represents two rectangular boxes, disposed in 90° each other.
Fig.?3Proportion of rats showing a left-biased exploration in the three different environments used in the study. From 50% above, a significant deviation was considered left lateralized exploration. From 50% below, a significant deviation was considered right lateralized exploration.
Fig.?2Exploration scores in three different environments of normal intact rats. During the study, two rats were lost by reasons unrelated to the experiments. Thus, from the initial amount of animals (<i>n</i> = 20), the final number was 18.
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