Neurons Expressing Estrogen Receptor α Differentially Innervate the Periaqueductal Gray Matter of Female Rats

Publication date: Available online 28 January 2019Source: Journal of Chemical NeuroanatomyAuthor(s): Silvana da Silva Pacheco, Tatiane Araujo Rondini, Jackson Cioni Bittencourt, Carol Fuzeti EliasAbstractThe periaqueductal gray matter (PAG) is a brainstem site involved in distinct autonomic and behavioral responses. Among them, the motor control of female sexual behavior, including lordosis, is well described. Lordosis reflex is highly dependent on increasing levels of estradiol that occur in the afternoon of the proestrus day in normally cycling females. This effect is thought to be mediated primarily via actions in the ventromedial nucleus of the hypothalamus (VMH). By binding to estrogen receptor α (ERα), estradiol changes the activity of VMH neurons that project to the PAG. Evidence also exists for the coordination of PAG outputs by estradiol-responsive neurons outside the VMH. However, a comprehensive analysis of these circuitries is not available. Using stereotaxic injection of the retrograde tracer Fluorogold in distinct columns of the PAG we performed a systematic mapping of neurons innervating the PAG and those coexpressing ERα immunoreactivity. We found that the forebrain projections to PAG columns are largely segregated and that most of the ERα expressing neurons preferentially target the lateral and the ventrolateral columns. Dual labeled neurons were mostly found in the intermediate subdivision of the lateral septal nucleus, the posterior aspect of the medial...
Source: Journal of Chemical Neuroanatomy - Category: Neuroscience Source Type: research