Lesions of NCM in adult males (Gobes and Bolhuis, 2007) suppress this behavioral preference for the tutor-song

Lesions of NCM in adult males (Gobes and Bolhuis, 2007) suppress this behavioral preference for the tutor-song. auditory processing, is usually increased by a socially relevant stimulus, acts rapidly to shape belief of subsequent stimuli experienced during interpersonal interactions, and modulates behavioral responses to these stimuli. Brain estrogens are likely to function similarly in both songbird sexes because aromatase and estrogen receptors are present in both male and female forebrain. Estrogenic modulation of belief in songbirds and perhaps other animals could fine-tune male advertising signals and female ability to discriminate them, facilitating mate selection by modulating behaviors. Keywords: Estrogens, Songbird, Social Context, Auditory Belief Although estrogens have long been acknowledged for their role in facilitating female behavioral responses to sexual stimuli, there has been a recent explosion of information that suggests a significant estrogenic influence on brain structures that serve learning and memory processes in both sexes. The 1990s brought a series of studies which showed that cellular effects of estrogens could mediate changes in memory function. For example, the hippocampus, a structure that is important in memory formation, was shown to undergo morphological changes in response to naturally fluctuating or experimentally manipulated estrogens in females, and electrophysiological responses in hippocampal slice preparations were changed when estradiol (specifically, 17-estradiol; E2) was added to the bath (Gould et al., TUG-770 1990; Woolley, 1992; Woolley et al., 1996; Wong and Moss, 1992). Systemic injection and intra-hippocampal estradiol infusion improved performance on learning tasks in rodents (Packard, 1998). These kinds of results support the proposal that memory deficits in perimenopausal and/or menopausal women might result from estradiol deficiency (for discussion see Frick, 2009; Shors, 2005). If so, some form of estrogen therapy could safeguard against memory loss. In addition, immunohistochemical and electrophysiological experiments have identified both classical (ER, ER) and novel (e.g. ERx, GPR-30) estrogen receptors on neuronal membranes, allowing estrogens to influence cellular physiology rapidly through non-genomic mechanisms, in addition to the classical steroid mechanism in which an estrogen binds to its intra-cellular receptors and ultimately influences gene transcription (reviewed in Woolley, 2007; McEwen, 2001; Mermelstein and Micevych, 2008; Roepke et al., 2011; Kelly and Levin, 2001). Our understanding of the proximate effects of estrogens on behavior has been advanced (and complicated) by the discovery of classical, and novel estrogen receptors in the brains of mammalian (McEwen, 2001; Simerly et al., 1990; Toran-Allerand, 2003; Rabbit Polyclonal to c-Jun (phospho-Tyr170) Taylor and Al-Azzawi, 2000; Kuiper et al., 1998) and non-mammalian species, including birds (Gahr, 2001; Ball et al., 2002; Saldanha et al., 2000), frogs (Chakroborty and Burmeister, 2010), and fish (Forlano et al., 2005; Pellegrini et al., 2005). In addition, the enzyme aromatase, which converts androgens to estrogens, also has been identified within male and female brains of many species (Callard et al., 1978; Saldanha et al., 2000; Beigon et al., 2010; Azcotia et al.; 2011; Forlano et al., 2005; Balthazart et al., 1996), allowing for the possibility that estrogens could be produced TUG-770 and act on nearby receptors to influence brain activity (Saldanha et al., 2011). Recent anatomical and physiological studies (Charitidi and Canlon, 2010) have also located intra- and extra-nuclear ERs at all levels of the auditory TUG-770 system from the inner hair cells to the cortex, encouraging research to discover their function in these auditory structures. Decades of work revealing estrogenic influences on behavior, its diverse mechanisms and sites of action, now provide an exciting opportunity to determine how estradiol and other estrogens modulate brain function and alter behavioral responses to stimuli. Even more challenging is to inquire how estrogenic interactions influence behaviors occurring within a realistic ethological context and time frame. Thirty years ago, TUG-770 experimenters in this field proposed the idea that hormones could modulate behaviors on a minute-to-minute basis (Harding, 1981; Wingfield, 1985). In addition, hormones can act in a region/steroid-specific manner.