Meeting Abstract

P2.185  Saturday, Jan. 5  Lateralization in aggressive behavior and brain morphology in the green anole lizard (Anolis carolinensis) PATTON, M.S.*; MEGAHED, T.; JOHNSON, M.A.; Trinity University mpatton@trinity.edu

Lizards are an ideal organism for studies of laterality in brain and behavior due to the lizard visual system; each eye is located on opposing sides of the head, and the retinal ganglion cells within the eyes project to the contralateral visual cortex for sensory processing. In addition, there is limited integration between the two hemispheres of the lizard brain. Thus, visual signals received by the left eye are primarily processed by brain regions in the right hemisphere, and vice versa. Previous research suggests that both behavioral and brain lateralization occur within the green anole (Anolis carolinensis). In this study, we build upon these data by studying both types of traits in the same individuals. We conducted 10 min laboratory arena trials, in which pairs of males interacted in a single cage, to determine eye orientation during male-male interactions. Our results showed that the majority of lizards exhibited a bias for left eye orientation during aggressive displays. In addition, dominant males in the trials displayed from a left eye orientation more than twice as frequently as subordinate males. Preliminary data on brain morphology suggest a 16% difference between the sizes of the neurons on the two sides of the brain within the preoptic area, a region involved in the motivation to perform displays. Our current work focuses on assessing the relationships between morphological laterality in the preoptic area and the amygdala in the brain, and both individual and species-level laterality in aggressive behavior.