Decreased Density of Serotonin Transporting Fibers in the Infant Williams Syndrome Amygdala
- Author(s): Groeniger, Kimberly Mieko
- Advisor(s): Semendeferi, Katerina
- Spitzer, Nicholas
- et al.
Williams Syndrome (WS) is a rare neurodevelopmental disorder characterized by a known genetic profile, hypersociability, and increased attention. This unique embodiment of social atypicalities allows for distinctions to be drawn between WS and other neurodevelopmental disorders, such as Autism Spectrum Disorder (ASD), as well as emotional disorders such as Major Depressive Disorder (MDD), Bipolar Disorder (BD), and Schizophrenia (SZ). While these disorders are not the focus of this study, the breadth of research performed with regards to these disorders involving neuroanatomy and its relation to social and behavioral profiles has provided a solid foundation for this study. Aspects of the WS social and behavioral phenotype have been extensively studied, however there has been less examination of the neuroanatomical characteristics which correlate with observed behaviors. The amygdala has been associated with the processing of socially salient information and coordination of responses to social stimuli, and within this structure serotonin is an active neurotransmitter responsible for modulating mood and emotional responses. To ascertain the role which serotonin plays within the infant WS amygdala, I examined the density of immunoreactive serotonin transporting (SERT-ir) fibers in the primary amygdaloid nuclei (lateral, basal, accessory basal, and central) of infants with WS compared to those of typically developing (TD) controls. Density in all four nuclei was decreased in WS as compared to TD, and in both WS and TD the central nucleus contained the highest density of SERT- ir fibers. This study contributes preliminary findings for future examinations of the serotonergic system in the WS amygdala.