Collaborative Research: Maternal Transitions in a Mouth-Brooding Cichlid

Louisiana State University, Baton Rouge LA

Investigators

Abstract

Maternal care has evolved in many animals, yet most research on the underlying neural mechanisms has been carried out only in mammals. This project capitalizes on that rich body of research to study maternal mouth-brooding in the cichlid fish Astatotilapia burtoni. This species offers an independently-evolved instance of robust maternal care. Here, the neural circuits regulating maternal behavior must interact intimately with the neural circuits regulating feeding to allow voluntary starvation in order not to eat the young despite significant loss of body mass. The proposed experiments will be conducted at Reed College & Louisiana State University, providing research and exchange opportunities between undergraduates at a top liberal arts institution and both undergraduate and graduate students from an EPSCoR institution (LSU). Understanding the degree to which mechanisms and brain regions for feeding have been co-opted for maternal care will inform our general understanding of the evolution of this important adaptive social behavior. In addition to addressing the evolution of maternal care, this research may impact human health research related to metabolic and feeding disorders as it may uncover novel mechanisms that allow decoupling of these circuits. This collaborative research project aims to understand the molecular and physiological mechanisms that underlie the behavioral switch from self-promoting behavior to offspring-promoting behavior that is required for robust maternal care. Astatotilapia burtoni has been a long standing model for sociogenomics and integrative animal behavior. Using immunohistochemistry, researchers and their students will quantify immediate-early gene expression in specific neuronal types across the "maternal brain" as well as assay cell types for changes in size or number. Using transriptomic approaches, they will quantify gene expression differences in candidate brain nuclei as well as peripheral signaling systems. Finally, in vivo neural recordings from neurons in the preoptic area will be used to determine physiological sensitivity to egg/fry versus food-related stimuli during different stages of maternal care. Fully describing the cichlid maternal brain as it interacts with feeding regulation is the long term collaborative agenda of the two researchers and allows them to capitalize on the synergy of simultaneously describing gene expression and functional studies. Students from Reed College and Louisiana State University will be involved in all aspects of this research. This project includes a math-biology collaboration to have students develop R scripts to interrogate similarity and differences between different gene expression networks in the different brain regions and different female groups. All resulting scripts and algorithms will be hosted online, disseminated through publication and presented by students at scientific conferences.