Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14049-900, Brazil.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2012 Sep;198(9):705-16. doi: 10.1007/s00359-012-0741-2. Epub 2012 Jul 3.
The caudomedial nidopallium (NCM) is a telencephalic area involved in auditory processing and memorization in songbirds, but the synaptic mechanisms associated with auditory processing in NCM are largely unknown. To identify potential changes in synaptic transmission induced by auditory stimulation in NCM, we used a slice preparation for path-clamp recordings of synaptic currents in the NCM of adult zebra finches (Taenopygia guttata) sacrificed after sound isolation followed by exposure to conspecific song or silence. Although post-synaptic GABAergic and glutamatergic currents in the NCM of control and song-exposed birds did not present any differences regarding their frequency, amplitude and duration after song exposure, we observed a higher probability of generation of bursting glutamatergic currents after blockade of GABAergic transmission in song-exposed birds as compared to controls. Both song-exposed males and females presented an increase in the probability of the expression of bursting glutamatergic currents, however bursting was more commonly seen in males where they appeared even without blocking GABAergic transmission. Our data show that song exposure changes the excitability of the glutamatergic neuronal network, increasing the probability of the generation of bursts of glutamatergic currents, but does not affect basic parameters of glutamatergic and GABAergic synaptic currents.
尾侧中隔核（NCM）是参与鸣禽听觉处理和记忆的端脑区域，但与 NCM 中的听觉处理相关的突触机制在很大程度上尚不清楚。为了确定听觉刺激在 NCM 中诱导的突触传递的潜在变化，我们使用切片制备方法，对在声音隔离后暴露于同种鸟鸣或静音后牺牲的成年斑胸草雀（Taenopygia guttata）的 NCM 中的突触电流进行路径钳记录。尽管 NCM 中的 GABA 能和谷氨酸能突触后电流在鸣禽暴露后在频率、幅度和持续时间方面没有任何差异，但与对照组相比，我们观察到在鸣禽暴露组中，阻断 GABA 能传递后，爆发性谷氨酸能电流的产生概率更高。与对照组相比，鸣禽暴露的雄性和雌性鸟类表达爆发性谷氨酸能电流的概率均增加，但在雄性中更为常见，即使不阻断 GABA 能传递，也会出现爆发。我们的数据表明，鸣禽暴露会改变谷氨酸能神经元网络的兴奋性，增加爆发性谷氨酸能电流的产生概率，但不会影响谷氨酸能和 GABA 能突触电流的基本参数。
