In all vertebrates, the pituitary is involved in the control of many important and complex processes such as reproduction, metamorphosis, growth, metabolism, stress response, and color change. Located below the hypothalamus, the pituitary is divided into two main parts: the neurohypophysis (pars nervosa) and the adenohypophysis (pars distalis and pars intermedia). The latter is composed of up to 8 different hormone-producing cell types and subjected to high plasticity. Pituitary plasticity is an important process allowing this organ to adapt its hormone production to the current demand along the life cycle of the animal. Research questions such as When in the life cycle does this plasticity play a role? What are the mechanisms allowing it? How are these mechanisms regulated? have been investigated for a long time but more intensely during the last decade due to the development of more powerful methodological tools.
The scope of this project is to target the following tree levels of pituitary plasticity: i) At the cellular level, the cells can change activity in response to different signals by regulating their receptor expression and by controlling their hormone production and release; ii) At the population level, in addition to the differentiation of specific progenitor cells, specific hormone producing cells are able to proliferate or to change phenotype thereby modifying the cell type composition in the pituitary as a whole; iii) At the structural level, cells have been observed to migrate and to send projections that allows formation of homotypic and heterotypic networks that may influence the secretory behavior of the cells. Using a comparative approach across vertebrate classes, our aim of this special issue is to discuss the different mechanisms involved in these three levels of plasticity in different pituitary cell types, the way they are regulated, and the role they play in the life cycle of an animal in the form of Original Research, Review, Mini-review, Methods, Opinion, and Hypothesis and Theory articles.
In all vertebrates, the pituitary is involved in the control of many important and complex processes such as reproduction, metamorphosis, growth, metabolism, stress response, and color change. Located below the hypothalamus, the pituitary is divided into two main parts: the neurohypophysis (pars nervosa) and the adenohypophysis (pars distalis and pars intermedia). The latter is composed of up to 8 different hormone-producing cell types and subjected to high plasticity. Pituitary plasticity is an important process allowing this organ to adapt its hormone production to the current demand along the life cycle of the animal. Research questions such as When in the life cycle does this plasticity play a role? What are the mechanisms allowing it? How are these mechanisms regulated? have been investigated for a long time but more intensely during the last decade due to the development of more powerful methodological tools.
The scope of this project is to target the following tree levels of pituitary plasticity: i) At the cellular level, the cells can change activity in response to different signals by regulating their receptor expression and by controlling their hormone production and release; ii) At the population level, in addition to the differentiation of specific progenitor cells, specific hormone producing cells are able to proliferate or to change phenotype thereby modifying the cell type composition in the pituitary as a whole; iii) At the structural level, cells have been observed to migrate and to send projections that allows formation of homotypic and heterotypic networks that may influence the secretory behavior of the cells. Using a comparative approach across vertebrate classes, our aim of this special issue is to discuss the different mechanisms involved in these three levels of plasticity in different pituitary cell types, the way they are regulated, and the role they play in the life cycle of an animal in the form of Original Research, Review, Mini-review, Methods, Opinion, and Hypothesis and Theory articles.
