Meeting Abstract
In reptiles, the dorsal and medial cortices (DC and MC) are important brain regions involved in the formation and storage of spatially relevant memories and exhibit plasticity in response to changes in spatial navigation. As with many reptiles, male Western fence lizards (Sceloporus occidentalis) are territorial during the breeding season. In other species, territorial males have larger cortical volumes than non-territorial males, however it is unknown if there are differences in the volumes of cortical brain regions between males and females. In this experiment, male and female S. occidentalis were captured from the wild during the breeding season and during the post-breeding season and were held in captivity for approximately four weeks, during which time, spatial memory tests were performed. At the end of the experiment, lizards were sacrificed and brains were collected and processed for histology. Cresyl-violet stained sections were used to quantify brain region volumes. There were no differences between the sexes or seasons in spatial learning abilities; lizards failed to demonstrate learning in either season. If plasticity of the cortical regions depends on differences in spatial navigation ability, there may not be differences in the volumes of the cortical regions. However, if plasticity in these brain regions depends on differences in space use, not differences in the ability to learn, male lizards during the breeding season will have larger DC and/or MC volumes compared to females during either season and compared to males during the non-breeding seasons.
