Neuronal activity of mitral-tufted cells in awake rats during passive and active odorant stimulation
Neuronal activity of mitral-tufted cells in awake rats during passive and active odorant stimulation
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DOI：
10.1152/jn.00095.2008
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发表时间：
2008-07-01
影响因子：
2.5
通讯作者：
Maldonado, Pedro E.
中科院分区：
文献类型：
--
作者：
Fuentes, Romulo A.;Aguilar, Marcelo I.;Maldonado, Pedro E.
气味剂诱导哺乳动物嗅球 (OB) 中二尖瓣/簇状 (MT) 细胞放电速率的特异性调节，诱导嵌入振荡局部场电位 (LFP) 中的神经元放电的时间模式。虽然大多数研究都检查了麻醉动物，但我们对 OB 单个单位的放电率和时间模式以及清醒行为哺乳动物的群体活动知之甚少。我们检查了行为大鼠在两项嗅觉任务中 MT 细胞和 LFP 信号的放电率和振荡活动：被动暴露（PE）和两种选择（TA）选择辨别。 MT 抑制反应在 TA 任务中占主导地位 (76.5%)，而 MT 兴奋反应在 PE 任务中占主导地位 (59.2%)。在 PE 和 TA 任务期间，分别有 79.0% 和 68.9% 的 MT 细胞出现 12 至 100 Hz 范围内的节律性放电。 PE 任务中出现的大多数气味剂都会以 > 50 Hz 的频率增加节律性放电，而在 TA 中，四种气味剂中的一种会产生 < 40 Hz 的适度增量。在 TA 任务期间，LFP 振荡明显受到气味剂的调节，在以 20 Hz 为中心的频率下增加其振荡功率，并在 > 50 Hz 的频率下降低功率。我们的结果表明，清醒动物中 MT 细胞的放电率反应受到行为调节，而抑制是这种调节的一个显着特征。单单位和多单位放电中振荡模式的发生也与刺激和行为背景有关，而神经元群的振荡模式表现出对气味刺激的强烈依赖性。
Odorants induce specific modulation of mitral/tufted (MT) cells' firing rate in the mammalian olfactory bulb (OB), inducing temporal patterns of neuronal discharge embedded in an oscillatory local field potential (LFP). While most studies have examined anesthetized animals, little is known about the firing rate and temporal patterns of OB single units and population activity in awake behaving mammals. We examined the firing rate and oscillatory activity of MT cells and LFP signals in behaving rats during two olfactory tasks: passive exposure (PE) and two-alternative (TA) choice discrimination. MT inhibitory responses are predominant in the TA task (76.5%), whereas MT excitatory responses predominate in the PE task (59.2%). Rhythmic discharge in the 12- to 100-Hz range was found in 79.0 and 68.9% of MT cells during PE and TA tasks, respectively. Most odorants presented in PE task increase rhythmic discharges at frequencies > 50 Hz, whereas in TA, one of four odorants produced a modest increment < 40 Hz. LFP oscillations were clearly modulated by odorants during the TA task, increasing their oscillatory power at frequencies centered at 20 Hz and decreasing power at frequencies > 50 Hz. Our results indicate that firing rate responses of MT cells in awake animals are behaviorally modulated with inhibition being a prominent feature of this modulation. The occurrence of oscillatory patterns in single- and multiunitary discharge is also related to stimulation and behavioral context, while the oscillatory patterns of the neuronal population showed a strong dependence on odorant stimulation.