Schoppa Nathan E, Urban Nathan N
Department of Physiology and Biophysics, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, MS3607 Campus Box C-240, Denver, CO 80262, USA.
Trends Neurosci. 2003 Sep;26(9):501-6. doi: 10.1016/S0166-2236(03)00228-5.
Odors elicit a well-organized pattern of activation in glomeruli across the surface of the olfactory bulb. However, the mechanisms by which this map is transformed into an odor code by the bulb circuitry remain unclear. Recent physiological studies in bulb slices have identified several synaptic processes that could be involved in sharpening odorant signals. Mitral cells within a single odorant receptor-specific network can be synchronized by dendrodendritic excitatory interactions in a glomerulus, whereas mitral cells in different networks engage in long-lasting lateral inhibition mediated by dendrodendritic synapses with interneurons. The emerging picture is one in which groups of mitral cells use a unique set of mechanisms to accomplish computational functions similar to those performed by analogous modular structures in other sensory systems.
气味会在嗅球表面的肾小球中引发一种组织有序的激活模式。然而，嗅球回路将这种图谱转化为气味编码的机制仍不清楚。最近对嗅球切片的生理学研究已经确定了几个可能参与增强气味信号的突触过程。单个气味受体特异性网络内的二尖瓣细胞可以通过肾小球中的树突 - 树突兴奋性相互作用而同步，而不同网络中的二尖瓣细胞则通过与中间神经元的树突 - 树突突触介导的持久侧向抑制来发挥作用。新出现的情况是，二尖瓣细胞群使用一组独特的机制来完成与其他感觉系统中类似模块化结构所执行的计算功能相似的功能。
