Abstract

SABINO, Nathalí Di Martino et al. Exploratory study on the effects of closuring cranial sutures on discriminative learning in rats. Acta comport. [online]. 2012, vol.20, n.2, pp. 143-155. ISSN 0188-8145.

Brain interventions, such as those produced by mechanical lesions, may affect organisms' behavior as well as their learning behavior. This study analyzed the effects of rat's cranial suture closing upon discriminative learning. Four surgical intact rats and nine rats that had different surgical procedures for the closing of cranial sutures were used as subjects. All subjects, under water-controlled deprivation, went through four experimental phases. In the first phase, lever responding was shaped and reinforced continuously for three consecutive sessions. In the second phase, fixed interval schedules were used (FI 4 s, FI 8 s, and FI 11 s). In the third phase, a multiple schedule composed of reinforcement (FI 11 s) and extinction, in the presence and absence of light respectively, was introduced. After 80% or more responses were emitted during FI components, stimulus functions were reverted (fourth phase). In general, results showed that surgical procedures did not have clear effects upon the animals' responding under the different schedules or under discriminative control (and its reversion). Based on the innovative methodology showed in this paper, future investigations will be able to use additional measures (e.g., neuroimage techniques) to evaluate, with more precision and control, the extend to which surgical procedures affected (or not) the development of the animals' brain.

Keywords : Discriminative learning; multiple schedule; cranial suture closure; bar press; rats.

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