Discrimination among odorants by single neurons of the rat olfactory bulb.
Discrimination among odorants by single neurons of the rat olfactory bulb.
复制标题
DOI：
10.1152/jn.1989.61.6.1161
复制
发表时间：
1989-06
影响因子：
2.5
通讯作者：
D. Wellis;John W. Scott;Theresa A. Harrison
中科院分区：
文献类型：
--
作者：
D. Wellis;John W. Scott;Theresa A. Harrison
1.用嗅觉刺激和电刺激嗅神经时大鼠嗅球、二尖瓣和簇状细胞进行细胞内和细胞外记录。通过注射辣根过氧化物酶和/或逆行激活来鉴定神经元。如前所述，在循环人工嗅觉范例中呈现多种浓度的至少一种气味物质，使得气味反应的研究成为可能。这一方法被扩展到多种气味物质，以比较它们的浓度-响应曲线。这种方法避免了由于不同气味作为刺激物的有效浓度不相等而导致的解释问题，这些问题是以前气味质量影响研究的特征。将细胞内事件和对电刺激的反应与气味诱导的尖峰序列活动进行比较，使我们能够开始描绘参与产生气味诱导反应的局部电路。2.本研究中72个细胞的浓度-反应曲线与以前报道的嗅球输出神经元的浓度-反应曲线相似，显示出棘波活动的时间模式随着气味浓度的阶跃变化而发生有序变化。然而，其中8个神经元对低浓度的气味表现出抑制反应，但对相同气味的高浓度却表现出类似潜伏期的兴奋反应。这些数据强调，要研究气味质量变化引起的模式变化，还必须仔细研究刺激强度的影响。这些数据还提供了证据，表明气味引起的时间模式本身可能并不是气味质量识别的代码。3.包括阈值以下浓度在内的对多种气味的完整浓度-反应曲线表明，尽管对不同气味的反应可以随着浓度而系统地演变，但对不同气味的反应可以通过非常不同的模式演变。例如，在一些细胞中，对不同气味的反应模式在形式上是互补的。这些结果表明，嗅球神经元的模式反应可以反映气味质量和强度的变化。4.用细胞内记录的方法比较气味刺激时棘波的时间模式与膜电位的变化。在某些情况下，棘波模式与明显的突触后电位密切相关。然而，也有几个明显的例外。在五个细胞中，在连续10次嗅觉的第一次嗅觉中可以看到显著的超极化，这与尖峰活动的暂停有关。在以下内容中
1. Intracellular and extracellular recordings were made from rat olfactory bulb mitral and tufted cells during odor stimulation and during electrical stimulation of the olfactory nerve. Neurons were identified by horseradish peroxidase injections and/or antidromic activation. The presentation of multiple concentrations of at least one odorant in a cyclic artificial sniff paradigm, as reported previously (10), allowed the study of odor responses. This approach was extended to multiple odorants to compare their concentration-response profiles. This procedure avoids the problems of interpretation resulting from nonequivalence of the effective concentrations of different odorants used as stimuli that have characterized previous studies of odor quality effects. Comparisons of intracellular events and responses to electrical stimulation with the odor-induced spike train activity allow us to begin to delineate the local circuitry involved in generating odor-induced responses. 2. The concentration-response profiles of the 72 cells in the present study are comparable to those previously reported for output neurons of the olfactory bulb, showing ordered changes in the temporal patterning of spike activity with step changes in odor concentration. However, eight of the neurons exhibited inhibitory responses to lower concentrations, but excitation, at similar latency, to higher concentrations of the same odorant. These data emphasize that to study pattern changes induced by changing odor quality the influence of stimulus intensity must also be carefully examined. The data also provide evidence that the temporal pattern evoked by an odorant is probably not in itself the code for odor quality recognition. 3. Complete concentration-response profiles, including subthreshold concentrations, to more than one odorant show that, although responses to the different odorant can evolve systematically with concentration, the responses to different odorants can evolve through very different patterns. For example, in some cells, the response patterns to different odors were complementary in form. These results demonstrate that the patterned responses of olfactory bulb neurons can reflect changes in odor quality as well as intensity. 4. Intracellular recording was employed to compare the temporal patterning of spikes during odor stimulation with membrane potential changes. In some cases, the spike pattern was closely correlated with apparent postsynaptic potentials. However, there were several clear exceptions. In five cells, a prominent hyperpolarization, seen in the first sniff of a series of 10 consecutive sniffs, was associated with pauses in spike activity. In the following