Tanabe T, Iino M, Takagi S F
J Neurophysiol. 1975 Sep;38(5):1284-96. doi: 10.1152/jn.1975.38.5.1284.
In the orbitofrontal olfactory area (LPOF) which was delineated in a previous paper, the capacity for odor discrimination was studied and compared with that in the anterior pyriform cortex (AP), the medial portion of the amygdala (MA), and the olfactory bulb (OB). Unanesthetized monkeys were used and eight odors were applied. 1. In the OB, 12.5% of the cells responded to only one odor, and the cells which responded to five odors were most numerous (25%). The total of the cells which responded to two, three, and four odors was 52%, which was less than the total of the cells responding to three, four, and five odors (67.5%). A small number oc cells responded to all eight odors (2.5%). The responses were classified as an increase (+type), a decrease (-type), or no change (no-type) in the rate of spike discharge. 2. In the AP and MA, no difference in the response patterns was found. The cells which responded to only one odor were 12.3% of the total, and the cells which responded to three different kinds of odors were most numerous (34.3%). The total of the cells responding to two, three, and four odors was 80%, much more than that in the OB. In addition, no cell responded to all eight odors. Concerning the response types, an increase followed by a decrease, or vice versa, in the rate of spike discharges (mixed-type) was observed which did not appear in the OB. Thus, an advance was found in the processing of olfactory information when compared with the OB. 3. A most striking finding in the LPOF was that 50% of the cells responded to only one odor. The cells which responded to two, three, and four odors decreased in this order, and no cell responded to more than five odors. These cells never responded to light or sound. 4. Using three very similar odors and five very different odors, it was apparent that the ability to discriminate odors of the same category is far more advanced in the LPOF than in the lower olfactory areas; and, in contrast, the lower olfactory areas also play a significant role in the discrimination of odors which belong to different categories. 5. It was concluded that the capacity for odor discrimination definitely improves along the olfactory nervous system from the lower to the higher areas. It is highly probable that a fine and sepcific discrimination of odors is performed in the LPOF.
在先前一篇论文中划定的眶额嗅觉区（LPOF），对气味辨别能力进行了研究，并与梨状前皮质（AP）、杏仁核内侧部分（MA）和嗅球（OB）中的气味辨别能力进行了比较。使用未麻醉的猴子，并施加了八种气味。1. 在嗅球中，12.5%的细胞仅对一种气味有反应，对五种气味有反应的细胞数量最多（25%）。对两种、三种和四种气味有反应的细胞总数为52%，低于对三种、四种和五种气味有反应的细胞总数（67.5%）。少数细胞对所有八种气味都有反应（2.5%）。反应分为放电率增加（+型）、放电率降低（-型）或无变化（无型）。2. 在梨状前皮质和杏仁核内侧部分，未发现反应模式有差异。仅对一种气味有反应的细胞占总数的12.3%，对三种不同气味有反应的细胞数量最多（34.3%）。对两种、三种和四种气味有反应的细胞总数为80%，远多于嗅球中的细胞总数。此外，没有细胞对所有八种气味都有反应。关于反应类型，观察到放电率先增加后降低或反之（混合型），这在嗅球中未出现。因此，与嗅球相比，在嗅觉信息处理方面有了进步。3. 在眶额嗅觉区最显著的发现是，50%的细胞仅对一种气味有反应。对两种、三种和四种气味有反应的细胞按此顺序减少，没有细胞对超过五种气味有反应。这些细胞对光或声音均无反应。4. 使用三种非常相似的气味和五种非常不同的气味，很明显，眶额嗅觉区对同一类气味的辨别能力比低级嗅觉区域先进得多；相反，低级嗅觉区域在辨别不同类气味方面也起着重要作用。5. 得出的结论是，气味辨别能力确实从低级到高级沿着嗅觉神经系统得到改善。很可能在眶额嗅觉区进行了精细而特异的气味辨别。
