Abstract

OLIVEIRA, Luiz Marcellino de  and  LEVITSKY, David A.. Efeitos dos choques a intervalos variáveis sobre o comportamento alimentar de ratos subnutridos. Cad. Pesqui. [online]. 1979, n.29, pp.111-124. ISSN 0100-1574.

A technique was developed to chronically measure the response to an environmental stress (variable shock presentation). Eight adult rats, 4 controls (25% casein) and 4 malnourished during lactation (12% casein) were allowed to obtain their food by pressing a bar (CRF) in daily sessions of 12 hours (night cycle). The water was ad libitum. Duringthe other 12 hours (day cycle) the animals lived in home cages with water and libitum but no food. After a stable baseline, a CS (light - 30 seconds) followed by US (shock - 15 seconds) were randomly presented, independently of the animal's behavior, from 6 to 48 times during the 12 hours session. The shock intensity was 1.0 and 2.0 mA. A platform was added to one side of the experimental chamber in order to allow a scape or avoidance response. Previously malnourished rats learned early and maintained higher percentagem of avoidance response than controls. The malnourished group also showed better adaptation to the stress situation by changing drastically the feeding pattern (number, size and duration of meals) thus maintaining their food intake more appropriatly than did the control group. The advantages of this procedure to analyse feeding behavior and two possible interpretations of the results are discussed.

Keywords : Subnutrição; Zootecnia.

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