Neuroendocrine cells are present in virtually all organs of the vertebrate body; however, it is yet uncertain whether they exist in the ovaries. Previous reports of ovarian neurons and neuron-like cells in mammals and birds might have resulted from misidentification. The aim of the present work was to determine the identity of neuron-like cells in immature ovaries of the domestic fowl. Cells immunoreactive to neurofilaments, synaptophysin, and chromogranin-A, with small, dense-core secretory granules, were consistently observed throughout the sub-cortical ovarian medulla and cortical interfollicular stroma. These cells also displayed immunoreactivity for tyrosine, tryptophan and dopamine b-hydroxylases, as well as to aromatic L-DOPA decarboxylase, implying their ability to synthesize both catecholamines and indolamines. Our results support the argument that the ovarian cells previously reported as neuron-like in birds, are neuroendocrine cells.

.AbstractBáez- Saldaña A, Fetter-Pruneda I, Fuentes-Farías AL, Granados-Rojas L, Gutiérrez-Ospina G, Martínez-Méndez R, Meléndez-Herrera E, Mendoza-Torreblanca J, Sandoval-Velasco M. Brain Plasticity, Signal Transduction and Epigenesis: a Missing Link Revealed. Annu Rev Biomed Sci 2009;11:T114-T122. It has been long thought that the brain reorganizes itself in response to environmental needs. Sensory experiences coded in action potentials are the mean by which information on the surroundings is introduced into neuronal networks. The information approaching the brain in the form of electrochemical codes must then be translated in biochemical, epigenetic and genetic ones. Only until recently we have begun understanding the underpinning of such informational transformations and how this process is expressed as neuronal plastic responses. Central for our comprehension of this matter is the finding that signals transduction cascades can modify gene expression by remodeling the chromatin through epigenetic mechanisms. Hence, chromatin remodeling seems to be the process by which experiences are "imprinted"