GH in the Central Nervous System: Lessons from the Growth Hormone Receptor Knockout Mouse

Various central nervous system (CNS) tissues express both growth hormone (GH) and its receptor (GHR), including those involved in memory and cognition. Studies show the presence of GHR in the pituitary, choroid plexus, hypothalamus, hippocampus, pituitary and the spinal cord during development and, to a lesser extent, in adults. This expression implies a role of GH signaling in growth, development and functionality of the CNS. While data on the function of GH in the CNS is sparse, several studies have been conducted using the GHR knockout (-/-) mouse in order to better understand this role. Abnormal growth hormone signaling in humans is the cause of various diseases that include Laron syndrome, GH deficiency and acromegaly. This article will review the research conducted using the GHR-/- mouse on the role of GH signaling in the CNS. Where possible, we will attempt to contextualize the animal data with respect to human disease.