Journal - Neuroscience and biobehavioral reviews

Abstract :

Songbirds sing at high rates within multiple contexts, suggesting that they are highly motivated to communicate and that the act of singing itself may be rewarding. Little is known about the neural regulation of the motivation to communicate. Dopamine and opioid neuropeptides play a primary role in reward seeking and sensory pleasure. In songbirds, these neurochemicals are found within brain regions implicated in both motivation and reward, including the medial preoptic nucleus (mPOA) and ventral tegmental area (VTA). Several lines of research indicate that dopamine and opioids in these regions play a role in birdsong that differs depending upon whether song is used to attract females (female-directed song) or is not directed towards other individuals (undirected song). Evidence is reviewed supporting the hypotheses 1) that distinct patterns of dopamine activity influence the motivation to produce undirected and female-directed song, 2) that undirected communication is intrinsically reinforced by immediate release of opioids induced by the act of singing, and 3) that directed communication is socially reinforced by opioids released as part of social interactions.Copyright © 2011. Published by Elsevier Ltd.

Journal - Journal of chemical neuroanatomy

Abstract :

Songbirds produce high rates of song within multiple social contexts, suggesting that they are highly motivated to sing and that song production itself may be rewarding. Progress has been made in understanding the neural basis of song learning and sensorimotor processing, however little is known about neurobiological mechanisms regulating the motivation to sing. Neural systems involved in motivation and reward have been conserved across species and in songbirds are neuroanatomically well-positioned to influence the song control system. Opioid neuropeptides within these systems play a primary role in hedonic reward, at least in mammals. In songbirds, opioid neuropeptides and receptors are found throughout the song control system and within several brain regions implicated in both motivation and reward, including the medial preoptic nucleus (POM) and ventral tegmental area (VTA). Growing research shows these regions to play a role in birdsong that differs depending upon whether song is sexually motivated in response to a female, used for territorial defense or sung as part of a flock but not directed towards an individual (undirected song). Opioid pharmacological manipulations and immunocytochemical data demonstrate a role for opioid activity possibly within VTA and POM in the regulation of song production. Although future research is needed, data suggest that opioids may be most critically involved in reinforcing song that does not result in any obvious form of immediate externally mediated reinforcement, such as undirected song produced in large flocks or during song learning. Data are reviewed supporting the idea that dopamine activity underlies the motivation or drive to sing, but that opioid release is what makes song production rewarding.

Journal - Behavioral neuroscience (United States )

Abstract :

Many social animals vocalize at high rates, suggesting that vocal communication is highly motivated and rewarding. In songbirds, much is known about the neural control of vocal behavior; however, little is known about neurobiological mechanisms regulating the motivation to communicate. This study examined a possible role for opioid neuropeptides in motivation and reward associated with song production in male European starlings (Sturnus vulgaris). Peripheral opioid blockade facilitated male song production. Furthermore, methionine-enkephalin immunolabeled fiber densities within brain regions in which opioids are known to regulate motivation and reward (i.e., the medial preoptic nucleus and ventral tegmental area) related positively to male song production. These data suggest that song production might be regulated by opioid activity within motivation and reward neural systems.Copyright 2005 APA.

Abstract :

DESCRIPTION (provided by applicant): Appropriate communication is at the heart of successful, healthy social interactions in humans. Deficits in social communication are a hallmark of several mental disorders, including autism spectrum disorders. Such disorders are characterized by extreme individual variability in the motivation to communicate, and in the ability to engage in socially appropriate communication, yet very little research has been devoted to understanding the neural bases of these issues. Songbirds provide an ideal model system in which to study brain mechanisms regulating appropriate social communication. In our model species we find the brain to differentially regulate communication in a context in which song is directed towards a female (goal-directed) versus song observed in large social groups (group-motivated). In past studies we find that some individuals communicate at high levels and others not at all. Associated with individual differences in communication are differences in activity within brain regions involved in motivation and reward. We have been able to motivate birds to communicate through pharmacological manipulations of dopamine receptors, suggesting dopamine as a candidate neurotransmitter system involved in stimulating communication in individuals that are not highly motivated to communicate. The experiments proposed here test the hypothesis that individual differences in context-appropriate communication are dependent upon dopamine activity within neural systems involved in motivation and reward. To test this hypothesis we will examine the effects of site-specific dopamine lesions (Aim 1) and site-specific dopamine receptor subtype manipulations (Aim 2) on communication within goal- directed and socially-motivated contexts in low- and high-communicating individuals. Neural circuits influenced by these manipulations will be examined after behavioral testing through examinations of markers of neuronal activity and other neurochemical markers. Comparisons will then be made of multiple dopaminergic markers in low- and high-communicators in both contexts to identify differences in the brain associated with natural individual variation in context-appropriate communication (Aim 3). The proposed research will identify manipulations that stimulate context-appropriate social interactions, which can be used in the design of clinical interventions in humans with deficits in the motivation to communicate. The proposed studies span from neurons, to neural circuits, to complex social behavior, integrate what is known about motivation with studies on communication, examine the influence of environment and social context on individuals displaying natural variation in behavior, and will provide treatment ideas for individuals with psychiatric disease. Deficits in social communication are a hallmark of several mental disorders, including autism spectrum disorders. Such disorders are characterized by extreme individual variability in the motivation to communicate, and in the ability to engage in socially appropriate communication. The proposed research will identify manipulations that stimulate context-appropriate social interactions, which can be used in the design of clinical interventions in humans with deficits in the motivation to communicate.

Abstract :

DESCRIPTION (applicant?s abstract): Environmental factors, hormones, and the brain interact to produce complex social behaviors, including those important for reproduction. The goal of the present series of studies, submitted by a new investigator, is to elucidate basic relationships between hormones and brain areas regulating sexual arousal and those important for the expression of behaviors reflecting sexual arousal. Songbirds provide an excellent model system for understanding this relationship. Song learning, production, and perception are known to be regulated by a specific group of sex steroid binding nuclei, known as "the song system"; however, little is known about brain areas regulating the motivation to sing. During the breeding season, song in male starlings (Sturnus vulgaris) is observed prior to pair formation and copulation and likely reflects male sexual arousal. The medial preoptic area (POM) is known in other species to be critical for the expression of male sexual arousal, and lesions to this nucleus disrupt singing and other courtship behaviors in male starlings, suggesting that the POM might regulate the motivation to sing within breeding context. The present proposal consists of four studies designed to understand the relationship between brain areas devoted exclusively to male song and the POM: 1) An anterograde and retrograde neuroanatomical tract tracing study aimed to determine neuroanatomical connections between the song system and the POM, 2) a POM lesion study comparing the effects of POM lesions on song sung within and outside of the breeding season, 3) an implant study in which an aromatase inhibitor will be implanted directly into the POM of castrated, testosterone treated male starlings to determine whether aromatase activity in the POM is critical for song sung in the breeding season, and 4) an investigation of the expression of the immediate early gene products of c-Fos and ZENK to explore further POM regulation of song in response to male or female stimulus birds presented during or outside of the breeding season. This work will define the role of the POM in male song and sexual behavior, could add another dimension to the current understanding of the neuroendocrine regulation of male song, and will serve to link two currently separate fields of research (research on birdsong and research on male sexual motivation), steps that are necessary to elucidate how the brain regulates complex social behaviors. In addition, this research could lay the groundwork for future studies on the etiology of disorders related to sexual arousal.

Abstract :

DESCRIPTION (applicant?s abstract): Environmental factors, hormones, and the brain interact to produce complex social behaviors, including those important for reproduction. The goal of the present series of studies, submitted by a new investigator, is to elucidate basic relationships between hormones and brain areas regulating sexual arousal and those important for the expression of behaviors reflecting sexual arousal. Songbirds provide an excellent model system for understanding this relationship. Song learning, production, and perception are known to be regulated by a specific group of sex steroid binding nuclei, known as "the song system"; however, little is known about brain areas regulating the motivation to sing. During the breeding season, song in male starlings (Sturnus vulgaris) is observed prior to pair formation and copulation and likely reflects male sexual arousal. The medial preoptic area (POM) is known in other species to be critical for the expression of male sexual arousal, and lesions to this nucleus disrupt singing and other courtship behaviors in male starlings, suggesting that the POM might regulate the motivation to sing within breeding context. The present proposal consists of four studies designed to understand the relationship between brain areas devoted exclusively to male song and the POM: 1) An anterograde and retrograde neuroanatomical tract tracing study aimed to determine neuroanatomical connections between the song system and the POM, 2) a POM lesion study comparing the effects of POM lesions on song sung within and outside of the breeding season, 3) an implant study in which an aromatase inhibitor will be implanted directly into the POM of castrated, testosterone treated male starlings to determine whether aromatase activity in the POM is critical for song sung in the breeding season, and 4) an investigation of the expression of the immediate early gene products of c-Fos and ZENK to explore further POM regulation of song in response to male or female stimulus birds presented during or outside of the breeding season. This work will define the role of the POM in male song and sexual behavior, could add another dimension to the current understanding of the neuroendocrine regulation of male song, and will serve to link two currently separate fields of research (research on birdsong and research on male sexual motivation), steps that are necessary to elucidate how the brain regulates complex social behaviors. In addition, this research could lay the groundwork for future studies on the etiology of disorders related to sexual arousal.

Abstract :

DESCRIPTION (applicant?s abstract): Environmental factors, hormones, and the brain interact to produce complex social behaviors, including those important for reproduction. The goal of the present series of studies, submitted by a new investigator, is to elucidate basic relationships between hormones and brain areas regulating sexual arousal and those important for the expression of behaviors reflecting sexual arousal. Songbirds provide an excellent model system for understanding this relationship. Song learning, production, and perception are known to be regulated by a specific group of sex steroid binding nuclei, known as "the song system"; however, little is known about brain areas regulating the motivation to sing. During the breeding season, song in male starlings (Sturnus vulgaris) is observed prior to pair formation and copulation and likely reflects male sexual arousal. The medial preoptic area (POM) is known in other species to be critical for the expression of male sexual arousal, and lesions to this nucleus disrupt singing and other courtship behaviors in male starlings, suggesting that the POM might regulate the motivation to sing within breeding context. The present proposal consists of four studies designed to understand the relationship between brain areas devoted exclusively to male song and the POM: 1) An anterograde and retrograde neuroanatomical tract tracing study aimed to determine neuroanatomical connections between the song system and the POM, 2) a POM lesion study comparing the effects of POM lesions on song sung within and outside of the breeding season, 3) an implant study in which an aromatase inhibitor will be implanted directly into the POM of castrated, testosterone treated male starlings to determine whether aromatase activity in the POM is critical for song sung in the breeding season, and 4) an investigation of the expression of the immediate early gene products of c-Fos and ZENK to explore further POM regulation of song in response to male or female stimulus birds presented during or outside of the breeding season. This work will define the role of the POM in male song and sexual behavior, could add another dimension to the current understanding of the neuroendocrine regulation of male song, and will serve to link two currently separate fields of research (research on birdsong and research on male sexual motivation), steps that are necessary to elucidate how the brain regulates complex social behaviors. In addition, this research could lay the groundwork for future studies on the etiology of disorders related to sexual arousal.