Instrumental responses of the common toad (Bufo arenarum) according to different external saline solutions

IURMAN, M. G. & MUZIO, R. N.

Huerta Grande, Córdoba

Congreso; I Reunión Conjunta de Neurociencias; 2009

Taller Argentino de Neurociencias y Sociedad Argentina de Investigación en Neurociencias (SAN)

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-AU; mso-fareast-language:ES;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Amphibians uptake water through the skin and have the ability to assess the osmotic and ionic properties of their external environments. The use of external solutions of different osmolarity as reinforcers provides an opportunity to analyse the behavior of animals without changing the systems perceptual committed. The aim of this study was to analyse the behavior of the common toad Bufo arenarum in an instrumental learning procedure using different concentrations of saline solutions as reinforcements. Three groups of toad, partially dehydrated, were trained in a runway situation: Appetitive (reinforced with deionized water in a container in the goal box, where animals gain weight), Aversive (reinforced with 800 mM NaCl solution, where they lose weight), and Neutral (reinforced with 300 mM NaCl solution, where they does not win nor lose weight). Running latency and pre and post-session weights were recorded. During the reinforcement period at the container, the amount of displacement and rubbing were recorded. Results showed a significant decrease of running latencies for the Appetitive group. The Aversive and Neutral groups presented high latencies with no differences between them. Once groups arrived in the goal compartment, Appetitive group showed the highest time on the container, as well as displacement and rubbings. The Neutral group significantly increased their time on the container and the amount of displacements through the sessions. The Aversive group presented a minimal time on the container. Globally, our results show that this training situation could be used for a comparative study of appetitive and aversive learning phenomena. In addition, we also are exploring the involvement of the medial pallium (homologous region to mammalian hippocampal formation) and the striatum (homologous area to mammalian amygdala) using the histochemical technique of AgNOR.