The gain modulation by N-methyl-D-aspartate in the projection neurons of robust nucleus of the arcopallium in adult zebra finches.
The song of zebra finch is stable in life after it was learned successfully. Vocal plasticity is thought to be a motor exploration that can support continuous learning and optimization of performance. The activity of RA, an important pre-motor nucleus in songbird's brain, influences the song directly. This variability in adult birdsong is associated with the activity of NMDA receptors in LMAN-RA synapses, but the detailed mechanism is unclear. The control of gain refers to modulation of a neuron's responsiveness to input and is critically important for normal sensory, cognitive, and motor functions. Here, we observed the change of gain in RA projection neurons after exogenous NMDA was applied to activate NMDA receptors using the whole-cell current clamp recording. We found that NMDA substantially increased the slope (gain) of the firing rate-current relationship in RA projection neurons. The AMPA receptor-dependent excitability played a crucial role in the modulation of gain by NMDA. These results suggested that NMDA receptors may regulate the dynamics of RA projection neurons by input-output gain.
Key Laboratory of Ecology and Environmental Science in Higher Education of Guangdong Province, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
Su-Qun
SQ
Liao
Guo-Qiang
GQ
Hou
Xuan
X
Pan
Cong-Shu
CS
Liao
Dong-Feng
DF
Li
D000200:Action Potentials / Q000502:physiology; D000367:Age Factors; D000818:Animals; D046369:Finches; D008297:Male; D016202:N-Methylaspartate / Q000378:metabolism / Q000502:physiology*; D009415:Nerve Net / Q000378:metabolism / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D016548:Prosencephalon / Q000166:cytology* / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000819:agonists / Q000502:physiology; D020308:Songbirds; D014828:Vocalization, Animal / Q000502:physiology
D016194:Receptors, N-Methyl-D-Aspartate; D016202:N-Methylaspartate