Development and Developmental Disorders of the Hypothalamus
|CYTOGENETIC DISEASE: PRADER-WILLI SYNDROME|
The hypothalamus in mammals arises as a part of the ventral diencephalon and the adjacent telencephalon, and its embryologic origins are intimately related to those of the optic chiasm and tracts and to the pituitary gland. Thus disorders that affect the hypothalamus fre- quently manifest with signs and symptoms resulting from dysfunction of neighboring, developmentally related structures. The developing neural tube is divided into three primary regions: forebrain, midbrain, and hindbrain. The forebrain is further subdivided into the telencephalon, which gives rise to the cerebral cortex and basal ganglia, and the diencephalon, from which the thalamus and hypothalamus are derived. The hypothalamus develops from the anterior portion of the diencephalon in a series of steps that involve the activation of suites of transcription factors, which determine the fates of the developing cell populations.