Postsynaptic neural activity regulates neuronal addition in the adult avian song control system.
A striking feature of the nervous system is that it shows extensive plasticity of structure and function that allows animals to adjust to changes in their environment. Neural activity plays a key role in mediating experience-dependent neural plasticity and, thus, creates a link between the external environment, the nervous system, and behavior. One dramatic example of neural plasticity is ongoing neurogenesis in the adult brain. The role of neural activity in modulating neuronal addition, however, has not been well studied at the level of neural circuits. The avian song control system allows us to investigate how activity influences neuronal addition to a neural circuit that regulates song, a learned sensorimotor social behavior. In adult white-crowned sparrows, new neurons are added continually to the song nucleus HVC (proper name) and project their axons to its target nucleus, the robust nucleus of the arcopallium (RA). We report here that electrical activity in RA regulates neuronal addition to HVC. Decreasing neural activity in RA by intracerebral infusion of the GABAA receptor agonist muscimol decreased the number of new HVC neurons by 56%. Our results suggest that postsynaptic electrical activity influences the addition of new neurons into a functional neural circuit in adult birds.
Departments of Biology, Psychology, and Otolaryngology, and Graduate Program in Neurobiology and Behavior, University of Washington, Seattle, WA 98195.
Tracy A
TA
Larson
Tsu-Wei
TW
Wang
Samuel D
SD
Gale
Kimberly E
KE
Miller
Nivretta M
NM
Thatra
Melissa L
ML
Caras
David J
DJ
Perkel
Eliot A
EA
Brenowitz
D000704:Analysis of Variance; D000818:Animals; D001837:Body Weights and Measures; D001896:Boron Compounds; D001921:Brain / Q000378:metabolism*; D001973:Bromodeoxyuridine; D058785:GABA-A Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology; D006575:Heterocyclic Compounds, 3-Ring; D006652:Histological Techniques; D007150:Immunohistochemistry; D008297:Male; D009118:Muscimol / Q000008:administration & dosage / Q000494:pharmacology; D055495:Neurogenesis / Q000502:physiology*; D046109:Passeriformes / Q000502:physiology*; D012235:Rhodamines; D055366:Synaptic Potentials / Q000502:physiology*; D014828:Vocalization, Animal / Q000502:physiology*; D014861:Washington
C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D058785:GABA-A Receptor Agonists; D006575:Heterocyclic Compounds, 3-Ring; D012235:Rhodamines; C412715:tetramethylrosamine; D009118:Muscimol; D001973:Bromodeoxyuridine
birdsong; songbird; testosterone