Intrinsic Functional Subregions of the Human Hypothalamus: Cortical Coupling and Subregional Organization Using 7-Tesla fMRI

Abstract The hypothalamus is vital to the regulation of the body’s metabolic state and behaviors related to survival. Despite its importance however, many questions exist regarding the intrinsic and extrinsic connections of the hypothalamus in humans, and its relationship with the cerebral cortex. Previous work on functional connectivity in the human hypothalamus have either treated it as a unitary structure or relied on methodological approaches that are limited in modeling its intrinsic functional architecture. However, the hypothalamus is a heterogeneous structure that may be composed of separate functional subunits. Here, we used resting-state data from ultra-high field 7-Tesla fMRI and a data-driven analytical approach to identify functional subregions of the human hypothalamus. We identified four functional hypothalamic subregions based on intrinsic functional connectivity with differing patterns of functional connectivity to the cerebral cortex. The anterior hypothalamic subregion showed strong connections with frontal, midline, and limbic cortical areas - many of which are canonical default mode regions. In contrast, the hypothalamus as a whole was only weakly connected to posterior sensorimotor regions. The findings support the use of ultra-high field, high-resolution imaging in providing a more incisive investigation of the human hypothalamus that respects its complex internal structure and extrinsic functional architecture.