Growth hormone found to have new role in development of brain's smell center

Airborne scent chemicals (inset) stimulate odor receptors in the nasal cavity, which send signals to the brain's olfactory bulb (yellow) located in the frontal lobe of the brain just above the nasal bone. These connections are set up during early development when sensory nerves in the nose send axons into the brain (blue and gold) that target specific neurons in the bulb to create a map of sensory information that displays a mirror symmetry across the bulb’s midline (dashed line). When IGF signaling is disrupted (right), the blue axons collapse toward the bulb’s midline, resulting in a distortion of this sensory map, demonstrating the critical role played by IGF in wiring the brain. (John Ngai/UC Berkeley; inset courtesy Nobel prize committee)