Neurons producing serotonin are among the earliest to be born in the developing central nervous system.
These cells are largely restricted to the hindbrain, where they form primarily in ventral regions.
The understanding of normal developmental processes provides a novel insight into mechanisms of pathogenesis: e.g., critical regulators of pituitary cell differentiation become the cause of hormone deficiencies when their genes carry mutations.
This chapter surveys current notions of pituitary development highlighting the impact of this knowledge on understanding pituitary pathologies as well as identifying the challenges and gaps for the future.
Activity-independent mechanisms are generally believed to occur as hardwired processes determined by genetic programs played out within individual neurons.
These include differentiation, migration and axon guidance to their initial target areas.
Fumigant activity of plant essential oils and components from horseradish (Armoracia rusticana), anise (Pimpinella anisum) and garlic (Allium sativum) oils against Lycoriella ingenua (Diptera: Sciaridae).
Gradually some of the cells stop dividing and differentiate into neurons and glial cells, which are the main cellular components of the CNS.
The newly generated neurons migrate to different parts of the developing brain to self-organize into different brain structures.
These simple, early vesicles enlarge and further divide into the telencephalon (future cerebral cortex and basal ganglia), diencephalon (future thalamus and hypothalamus), mesencephalon (future colliculi), metencephalon (future pons and cerebellum), and myelencephalon (future medulla).
The CSF-filled central chamber is continuous from the telencephalon to the spinal cord, and constitutes the developing ventricular system of the CNS.
A groove forms along the long axis of the neural plate and, by week four of development, the neural plate wraps in on itself to give rise to the neural tube, which is filled with cerebrospinal fluid (CSF).