Complex sentence: Neuroendocrinology has subsequently expanded its area of interest substantially to study the numerous interconnections of the endocrine and nervous systems, and considers both the extensive functionalities of that connection and the biological features of the cells that participate.
Split into simpler sentences: Neuroendocrinology has subsequently expanded substantially to study numerous interconnections of the endocrine and nervous systems. The, and considers the extensive communication functionalities and the biological features of the cells that participate.