The canary song system has proven to be a rich source of information on such general issues as neural sexual dimorphism, effects of steroids on brain development and function, adult neural plasticity, recovery of function, and lateralization. The proposed research will integrate behavioral observation, hormone manipulation, and sophisticated quantitative microanatomical techniques in adult canaries to further study these issues. The first two experiments study the behavioral and neuroanatomical consequences of experimentally preventing the normal fall drop in sex steroids. 1. If treatment with testosterone (T) prevents the neural regression and later song reorganization seen in untreated males, it would suggest that processing space in the neural network controlling song is limited: anatomical """"""""erasure"""""""" of old circuits is necessary to permit the synaptic realignment which encodes the next year's song. 2. Lesions in left song control nuclei result in substantial song disruption. Recovery using the right hemisphere occurs the following spring. If T-treatment prevents this behavioral recovery, it would suggest that T can maintain lateralized function, and must be removed if there is to be any reorganization of function. Experiment three combines Golgi staining and electron microscopy to find and characterize new synapses in the adult. The P.I.'s computer-microscope system will be used to highlight sites of T-induced dendritic growth. Subsequent EM examination will indicate whether synapses on these new dendrites have a distinctive appearance, and if so, whether new synapses occur elsewhere on neurons from T-treated or control birds. Experiment four combines Golgi staining and autoradiography in order to characterize the song system neurons which derive from adult neurogenesis, and to determine whether endogenous steroids affect their differentiation or fate. Thus, does adult neurogenesis contribute significantly to rejuvenated capacity in the song system? These experiments study questions closely related to human health. Must neural regression occur for there to be forgetting? Are there circumstances under which some behavior must be forgotten in order to permit acquisition of another? Is reallocation of function (a mechanism for recovery from brain damage which also occurs in humans) facilitated by general neural regression in the damaged area? Can the morphology of new synapses and new neurons in an adult nervous system be used to predict conditions which augment their occurance and functional incorporation into a brain region?

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD021033-02
Application #
3319665
Study Section
Neurology B Subcommittee 1 (NEUB)
Project Start
1985-12-01
Project End
1988-11-30
Budget Start
1986-12-01
Budget End
1987-11-30
Support Year
2
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Cornell University
Department
Type
Schools of Arts and Sciences
DUNS #
City
Ithaca
State
NY
Country
United States
Zip Code
14850
Airey, D C; DeVoogd, T J (2000) Greater song complexity is associated with augmented song system anatomy in zebra finches. Neuroreport 11:1749-54
Airey, D C; DeVoogd, T J (2000) Greater song complexity is associated with augmented song system anatomy in zebra finches. Neuroreport 11:2339-44
Benton, S; Nelson, D A; Marler, P et al. (1998) Anterior forebrain pathway is needed for stable song expression in adult male white-crowned sparrows (Zonotrichia leucophrys). Behav Brain Res 96:135-50
Wallhausser-Franke, E; Nixdorf-Bergweiler, B E; DeVoogd, T J (1995) Song isolation is associated with maintaining high spine frequencies on zebra finch 1MAN neurons. Neurobiol Learn Mem 64:25-35
Nixdorf-Bergweiler, B E; Wallhausser-Franke, E; DeVoogd, T J (1995) Regressive development in neuronal structure during song learning in birds. J Neurobiol 27:204-15
Wallhausser-Franke, E; Collins, C E; DeVoogd, T J (1995) Developmental changes in the distribution of NADPH-diaphorase-containing neurons in telencephalic nuclei of the zebra finch song system. J Comp Neurol 356:345-54
Reasner, D S; Johnston, R E; DeVoogd, T J (1993) Alteration of the bed nucleus of the stria terminalis (BNST) in young female Djungarian hamsters (Phodopus campbelli) exposed to adult males. Behav Neural Biol 60:251-8
Devoogd, T J; Krebs, J R; Healy, S D et al. (1993) Relations between song repertoire size and the volume of brain nuclei related to song: comparative evolutionary analyses amongst oscine birds. Proc Biol Sci 254:75-82
Hill, K M; DeVoogd, T J (1991) Altered daylength affects dendritic structure in a song-related brain region in red-winged blackbirds. Behav Neural Biol 56:240-50
DeVoogd, T J (1991) Endocrine modulation of the development and adult function of the avian song system. Psychoneuroendocrinology 16:41-66

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