Neuronal Intrinsic Physiology Changes During Development of a Learned Behavior.
Juvenile male zebra finches learn their songs over distinct auditory and sensorimotor stages, the former requiring exposure to an adult tutor song pattern. The cortical premotor nucleus HVC (acronym is name) plays a necessary role in both learning stages, as well as the production of adult song. Consistent with neural network models where synaptic plasticity mediates developmental forms of learning, exposure to tutor song drives changes in the turnover, density, and morphology of HVC synapses during vocal development. A network's output, however, is also influenced by the intrinsic properties (e.g., ion channels) of the component neurons, which could change over development. Here, we use patch clamp recordings to show cell-type-specific changes in the intrinsic physiology of HVC projection neurons as a function of vocal development. Developmental changes in HVC neurons that project to the basal ganglia include an increased voltage sag response to hyperpolarizing currents and an increased rebound depolarization following hyperpolarization. Developmental changes in HVC neurons that project to vocal-motor cortex include a decreased resting membrane potential and an increased spike amplitude. HVC interneurons, however, show a relatively stable range of intrinsic features across vocal development. We used mathematical models to deduce possible changes in ionic currents that underlie the physiological changes and to show that the magnitude of the observed changes could alter HVC circuit function. The results demonstrate developmental plasticity in the intrinsic physiology of HVC projection neurons and suggest that intrinsic plasticity may have a role in the process of song learning.
['Ross|Matthew T|MT|', 'Flores|Diana|D|', 'Bertram|Richard|R|', 'Johnson|Frank|F|', 'Hyson|Richard L|RL|']
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione D000161:Acoustic Stimulation D000344:Afferent Pathways D000375:Aging D000818:Animals D004558:Electric Stimulation D018691:Excitatory Amino Acid Antagonists D046369:Finches D018756:GABA Antagonists D053400:High Vocal Center D066298:In Vitro Techniques D007858:Learning D008297:Male D008959:Models, Neurological D008962:Models, Theoretical D009415:Nerve Net D009474:Neurons D018408:Patch-Clamp Techniques D010852:Picrotoxin D014828:Vocalization, Animal
zebra finch HVC modeling ion channels intrinsic plasticity birdsong