Vocal communication in numerous animal species is critical for successful social interactions. Little attention has focused on neurobiological mechanisms regulating the motivation to communicate or how the brain ensures that communication occurs in an appropriate social context. In my laboratory my students and I examine these topics in songbird model systems. My major research emphasis over the last year was on: 1) how the brain regulates motivation or reward associated with vocal communication, 2) how the brain ensures that communication takes place within an appropriate context, in response to appropriate social stimuli, and 3) how the brain regulates selective behavioral responses to communication signals.
The laboratory was productive this year; with 7 publications plus 3 manuscripts accepted pending revision. We gathered additional support this year for the idea that neurochemicals involved in motivation and reward influence male song production. Specifically our data indicate that dopamine motivates males to communicate whereas opioid neuropeptides reward vocal production. I wrote an invited review paper summarizing our data on dopamine and opioid involvement in male song production for Frontiers in Neuroendocrinology. We additionally gathered evidence that the catecholamines dopamine (a neurochemical involved in motivation and reward) and norepinephrine (a neurochemical involved in arousal and attention) play an important role in female responses to male song. We developed a method for measuring the rewarding properties of hearing song and found that opioid markers in brain areas in which opioids are rewarding are linked to the reward value of hearing song. Together our results provide support for the idea that the brainís natural motivation and reward systems (the same systems implicated in regulating feeding, sexual behavior, and drug abuse in humans) also participate in both the production and reception of vocal signals. Furthermore our data suggest that the factors rewarding song may differ depending upon the context in which song is produced.
This year we made progress on an R01 award from the National Institutes of Health (NIH) to examine a role for the neurotransmitter dopamine in motivation and reward associated with communication in different social contexts. I also applied for and successfully received a competitive renewal of this proposal.
With respect to university and national service, I agreed to serve on a grant review panel for NSF. I co-hosted the international meeting of the Society for Behavioral Neuroendocrinology, and was asked to run for Secretary of this society. I additionally served as director of graduate studies, and served on the graduate admissions committee for the Neuroscience Training Program among other assignments. I also agreed to a 3 year term on the Institutional Animal Care and Use Committee (IACUC).
This year my lab consisted of 1 postdoctoral fellow and 2 PhD graduate students. One of the graduate students earned her PhD and is now working as a postdoctoral fellow in Dr. Michelle Ciucciís lab in the Department of Communicative Disorders here on campus. Several undergraduate directed studies students were active in many aspects of our research this past year. My students and postdoc presented posters at the Society for Neuroscience and Society for Behavioral Endocrinology meetings. The students and I now meet every other week with the Gammie lab to discuss research in the field of behavioral neurobiology.
This year I taught the neuroscience, endocrinology, immune function, and behavior sections of Introductory Animal Biology (Zoo 101) and my course in Endocrinology.
- Zoology 101 - Animal Biology
- Zoology 603 - Endocrinology
- Zoology 962/Neurosci 675 - Graduate Seminar in Ethology: Behavior,
Brain, and Evolution
Note to prospective graduate students:
I welcome motivated graduate students with diverse interests
in animal behavior or behavioral neuroscience related
to animal communication and other social behaviors.
Graduate students currently supervised:
- Melissa Cordes, Melissa is interested in understanding links between social status and vocal communication. Her current studies focus on the involvement of androgen receptors and opioids in the dramatic increases in singing behavior observed in male starlings that become socially dominant.
Students supervised who recently earned graduate degrees:
- Cindi A. Kelm-Nelson (PhD 2012)
- Benjamin A. Pawlisch (PhD 2012)
- Sarah Jane Alger (PhD 2010)
- Sarah Ann Heimovics (PhD 2008)
- Kelm-Nelson, C. A., Stevenson, S. A., Cordes, M. A., and Riters, L. V. (in press). Modulation of male song by naloxone in the medial preoptic nucleus. Behavioral Neuroscience.
- Ellis, J. M. S. and Riters, L.V. (in press). Patterns of phosphorylated tyrosine hydroxylase vary with song production in female starlings. Brain Research.
- Pawlisch, B. A., Kelm-Nelson, C. A., Stevenson, S. A., and Riters, L.V. (2012). Behavioral indices of breeding readiness in female European starlings correlate with immunolabeling for catecholamine markers in brain areas involved in sexual motivation. General and Comparative Endocrinology. 179(3), 359-368.
- Kelm-Nelson, C. A., Stevenson, S. A., Riters, L. V. (2012). Context-dependent links between song production and opioid-mediated analgesia in male European starlings (Sturnus vulgaris). PLoS One. 7(10).
- Ellis, J. M. S. and Riters, L. V. (2012). Patterns of FOS protein induction in singing female starlings. Behavioural Brain Research. 237, 148-156.
- Riters, L.V. and Stevenson, S.A. (2012). The Role of Reward in Vocal Production: Song-associated Place Preference in Songbirds. Physiology & Behavior. 106(2):87-94.
- Ellis, J. M. S. and Riters, L. V. (2012). Vocal parameters that indicate threat level correlate with FOS immunolabeling in social and vocal control brain regions. Brain, Behavior and Evolution. 79(2),128-140.
- Heimovics, S. A., Salvante, K. G., Sockman, K.W., Riters, L.V. (2011). Individual differences in the motivation to communicate relate to levels of midbrain and striatal catecholamines and related markers in male European starlings. Hormones and Behavior. 60(5), 529-539.
- Alger, S. J., Juang, C., Riters, L. V. (2011). Social affiliation relates to tyrosine hydroxylase immunolabeling in male and female zebra finches (Taeniopygia guttata). Journal of Chemical Neuroanatomy. 42(1), 45-55.
- Pawlisch, B. A., Stevenson, S.A., and Riters, L. V. (2011). Alpha 1-noradrenergic receptor antagonism disrupts female songbird responses to male song. Neuroscience Letters. 496(1), 20 -24.
- Heimovics, S. A., Cornil, C. A., Ellis, J. M. S., Ball, G. F. and Riters, L. V. (2011). Seasonal and individual variation in singing behavior correlates with alpha 2-noradrenergic receptor density in brain regions implicated in song, sexual, and social behavior. Neuroscience. 182, 133-143.
- Kelm, C. A. Forbes-Lorman, R. M., Auger, C. J., Riters, L. V. (2010). Mu-opioid receptor densities are depleted in regions implicated in agonistic and sexual behavior in male European starlings (Sturnus vulgaris) defending nest sites and courting females. Behavioural Brain Research. 219(1), 15-22.
- Pawlisch, B. A. and Riters, L.V. (2010). Selective behavioral responses to male song are affected by the dopamine agonist GBR-12909 in female European starlings (Sturnus vulgaris). Brain Research. 1353, 113-124.
- Heimovics, S. A., Cornil, C. A., Ball, G. F., and Riters, L. V. (2009). D1-like dopamine receptor density in nuclei involved in social behavior correlates with song in a context-dependent fashion in male European starlings. Neuroscience. 159(3), 962-973.
- Alger, S. J., Maasch, S. N., and Riters. L. V. (2009). Lesions to the medial preoptic nucleus affect immediate early gene immunolabeling in brain regions involved in song control and social behavior in male European starlings. European Journal of Neuroscience, 29(5), 970-982.
- Heimovics, S. A. and Riters, L. V. (2008). Evidence that dopamine within motivation and song control brain regions regulates birdsong context-dependently. Physiology and Behavior, 95, 258-266.
Reviews and Invited Chapters
- Riters, L. V. (2012). Invited review: The role of motivation and reward neural systems in vocal communication in songbirds. Frontiers in Neuroendocrinology. 33, 194-209.
- Riters, L. V. (2011). Pleasure seeking and birdsong. Neuroscience and Biobehavioral Reviews. Special Issue: Proceedings from the Festschrift for Dr. Jaak Panksepp: A celebration of pioneering research in affective neuroscience. 35, 1837-1845.
- Riters, L.V. and Alger, S.J. (2011). Hormonal regulation of avian courtship and mating behaviors. In: Hormones and Reproduction of Vertebrates (vol. 4), David O. Norris and Kristin H. Lopez (eds), Academic Press, San Diego, CA.
- Riters, L. V. (2010). Evidence for opioid involvement in the motivation to sing. Invited review, special issue on the Chemical Neuroanatomy of Birdsong. Journal of Chemical Neuroanatomy. 39(2), 141-150. [Epub 2009].
- Ball, G.F., Riters, L.V., MacDougall-Shackleton, S. A., and Balthazart, J. (2008). Sex Differences in Brain and Behavior and the Neuroendocrine Control of the Motivation to Sing. In: The Neuroscience of Birdsong, H.P. Zeigler and P.R. Marler (eds) Cambridge University Press, Cambridge, UK. pp. 320-331.