One of the most important functions of the nervous system is to store information and produce adaptive behaviors that reflect prior experience. To uncover circuits and cellular mechanisms that can foster rapid and accurate learning, we use molecular, pharmacological, anatomical and behavioral approaches to investigate neural mechanisms underlying vocal learning and plasticity in songbirds. Like humans, songbirds exhibit strong innate preferences for reproducing vocalizations typical of their own species, and learning occurs quickly if these stimuli are heard at an appropriate age.
Recent work indicates that some of the same neural pathways, transmitter systems, and biochemical cascades linked generally to reinforcement-based learning also are critical for vocal learning. One aspect of our work aims to characterize biochemical and synaptic changes related to the encoding of auditory memories used as templates for vocal imitation. Currently, several studies are focused on elucidating the role of basal ganglia pathways and dopaminergic neuromodulatory systems on establishing song-related memories that will later serve as the target for vocal development. We also employ the avian song system as a model in which to study adaptive sensorimotor plasticity. The broad aim of our research program is to uncover biological processes that underlie learning and regulate its efficiency.
- Nordeen, K.W., and E.J. Nordeen (2010) Deafening-induced vocal deterioration in adult songbirds is reversed by disrupting a basal ganglia-forebrain circuit. J. Neurosci, 30:7392-400.
- Nordeen, E.J., D. Holtzman, K.W. Nordeen (2009) Increased Fos expression among midbrain dopaminergic cell groups during birdsong tutoring. Eur. J Neurosci. 30: 662-670.
- Nordeen, K.W. and E.J. Nordeen (2008) Circuits and Cellular Mechanisms of Sensory Acquisition. In: The Neuroscience of Birdsong. P. Hzeigler and P. Marler (Eds), Cambridge University Press, pp. 256-270.
- Hein, A., A. Sridharan, K.W. Nordeen, and E.J. Nordeen (2007) Characterization of cell types expressing CaMKII within the avian basal ganglia. Brain Research, 1155: 125-133.
- Scott, L., E.J. Nordeen, and K.W. Nordeen (2007) lMAN lesions prevent song degradation after deafening without reducing HVC neuron addition. Dev. Neurobiol, 67: 1407-18.
- Singh, T.D., E.J. Nordeen, & K.W. Nordeen (2005). Song tutoring triggers CaMKII phosphorylation within a specialized portion of the avian basal ganglia. J Neurobiol, 65(2): 179-191.
- Heinrich, J.E., K.W. Nordeen, & E.J. Nordeen (2005). Dissociation between extension of the sensitive period for avian vocal learning and the timing of dendritic spine loss in the lateral magnocellular nucleus of the anterior nidopallium. Neurobiol. Learning and Memory, 83: 143-150.
- Scott, L., T.D. Singh, E.J. Nordeen, & K.W. Nordeen (2004). Developmental patterns of NMDAR expression within the song system do not recur during adult vocal plasticity in zebra finches. J. Neurobiol, 58, 442-54.
- Nordeen, K.W. & E.J. Nordeen (2004). Synaptic and molecular mechanisms regulating plasticity during early learning. Ann. N.Y. Acad. Sci., 1016, 416-437.
- Heinrich, J.E., Singh, T.D., Nordeen, K.W., & Nordeen, E.J. (2003). NR2B downregulation in a forebrain region required for avian vocal learning is not sufficient to close the sensitive period for song learning. Neurobiology of Learning and Memory, 79, 99-108.
- Singh, T.D., Heinrich, J.E., Wissman, A. Brenowitz, E.A., Nordeen, E.J. & K.W Nordeen (2003). Seasonal regulation of NMDA receptor NR2B mRNA in the adult canary song system. J. Neurobiol., 54, 593-603.
- Heinrich, J.E., Singh, T.D., Sohrabji, F., Nordeen, K.W., & Nordeen, E.J. (2002). Developmental and hormonal regulation of NR2A mRNA in forebrain regions controlling avian vocal learning. Journal of Neurobiology, 51, 149-159.
- Scott, L., Nordeen, E.J., & Nordeen, K.W. (2000). The relationship between rates of HVc neuron addition and vocal plasticity in adult songbirds. Journal of Neurobiology, 43, 79-88.
- Singh, T.D., Basham, M.E., Nordeen, E.J., & Nordeen, K.W. (2000). Early sensory and hormonal experience modulate age-related changes in NR2B mRNA within a forebrain region controlling avian vocal learning. Journal of Neurobiology, 44, 82-94.
- Basham, M.E., Sohrabji, F., Singh, T.D., Nordeen, E.J., & Nordeen, K.W. (1999). Developmental regulation of NMDA receptor 2b subunit mRNA and ifenprodil binding in the zebra finch anterior forebrain. Journal of Neurobiology, 39, 155-167.
- Ward, B., Nordeen, K.W., & Nordeen, E.J. (1998). Individual variation in neuron number predicts differences in the propensity for avian vocal imitation. Proceedings of the National Academy of Sciences, 95, 1277-1282.
- Nordeen, K.W., & Nordeen, E.J. (1997). Anatomical and synaptic substrates for avian song learning. Journal of Neurobiology, 33, 532-548.
- Aamodt, S.M., Nordeen, E.J., & Nordeen, K.W. (1996). Blockade of NMDA receptors during song model exposure impairs song development in juvenile Zebra finches. Learning and Memory, 65, 91-98.
- Basham, M.E., Nordeen, E.J., & Nordeen, K.W. (1996). Blockade of NMDA receptors in the anterior forebrain impairs sensory acquisition in the Zebra finch. Neurobiology of Learning and Memory, 66, 295-304.
- Aamodt, S.M., Nordeen, E.J., & Nordeen, K.W. (1995). Early isolation from conspecific song does not affect the normal developmental decline of NMDA receptor binding in an avian song nucleus. Journal of Neurobiology, 27, 76-84.
- Nordeen, K.W., & Nordeen, E.J. (1992). Auditory feedback is necessary for the maintenance of stereotyped song in adult Zebra finches. Behavioral and Neural Biology, 57, 58-66.
- Nordeen, E.J., & Nordeen, K.W. (1990). Neurogenesis and sensitive periods in avian vocal learning. Trends in Neurosciences, 13, 31-36.
For the past 25 years, my research has been supported by grants from the National Institute of Mental Health and the National Science Foundation. Current funding support also comes from the Schmitt Foundation, and the Whitehall Foundation.
Former Graduate Students and Postdocs
Dr. Farida Sohrabji, Professor, Texas A&M
Dr. Sandra Aamodt, Senior Editor, Nature Neuroscience
Dr. Michael Burek, Merck Pharmeceuticals
Dr. Mark Basham, Asst Professor, Metropolitan State College of Denver
Dr. Bonnie Ward, Post-doc, Wellesley College
Dr. Luisa Scott, Post-doc, U. of Texas, Austin
Dr. Julie Heinrich, Post-doc, U. Notre Dame
Marla Bruns (Master's student), MD/PhD program, Syracuse U.
Dr. Tryambak Singh (Postdoc), Assoc. Professor, Baranas Hindu U.