Convergence of multimodal sensory input onto higher-level neurons of the crayfish olfactory pathway.
Convergence of multimodal sensory input onto higher-level neurons of the crayfish olfactory pathway.
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多模式感觉输入汇聚到小龙虾嗅觉通路的高级神经元上。
DOI：
10.1152/jn.2000.84.6.3043
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
MellonJr,D
中科院分区：
文献类型：
--
作者：
MellonJr,D
克氏原虾外侧原大脑中间神经元(LPI)的细胞内电生理研究表明，多模式感觉信息汇聚到甲壳类中枢嗅觉通路的这些高级细胞上。嗅觉或电击的触角刺激在一些LPI中产生兴奋抑制序列，触角的电刺激或流体动力刺激也是如此。对同侧复眼的光刺激在LPI中产生兴奋性反应，通常以一连串脉冲爆发的形式出现，这些脉冲爆发的时间与这些神经元的自发振荡活动的峰值同步。对嗅叶、触角传入输入的终止点或副叶的局部电刺激，在高级视觉和触觉输入汇聚的地方，也会在LPI中产生短暂的兴奋和延迟的、长时间的抑制。这两个阶段的活动都被认为是通过中脑投射神经元传递到外侧前脑的，中脑投射神经元在嗅叶和副叶有广泛的树突分支。兴奋性通路被认为是直接与靶LPI突触，而抑制通路可能是间接的，并通过前脑外侧区的GABA能中间神经元介导。有证据表明，突触前和突触后抑制都会抑制LPI的活动。初步观察表明，毗邻半椭圆形小体的一小群神经元对LPI活性有抑制作用。LPI活性的多模式抑制和兴奋性调制可能在小龙虾嗅觉系统中气味的上下文识别中发挥作用。
Intracellular electrophysiological studies of lateral protocerebral interneurons (LPIs) in the crayfishProcambarus clarkiihave revealed convergence of multimodal sensory information onto these higher-level cells of the crustacean central olfactory pathway. Antennular stimulation by odors or electrical shocks generates excitatory-inhibitory sequences in some LPIs as does electrical or hydrodynamic stimulation of the antennae. Photic stimulation of the ipsilateral compound eye generates excitatory responses in LPIs, usually in the form of trains of impulse bursts that are timed to the peaks of the spontaneous oscillatory activity that characterizes these neurons. Focal electrical stimulation of the olfactory lobe, the termination point of antennular afferent input, or the accessory lobe, where higher-level visual and tactile inputs converge, also generates brief excitation and a delayed, prolonged inhibition in LPIs. Both phases of this activity are thought to be transmitted to the lateral protocerebrum via deutocerebral projection neurons, which have extensive dendritic arborizations in the olfactory lobe and the accessory lobe. The excitatory pathway is thought to synapse directly with target LPIs, whereas the inhibitory pathway is probably indirect and mediated through GABAergic interneurons within the lateral protocerebrum. There is evidence that both presynaptic and postsynaptic inhibition suppress activity in LPIs. Preliminary observations suggest that a small cluster of neurons adjacent to the hemi-ellipsoid body are inhibitory to LPI activity. Multimodal inhibitory and excitatory modulation of LPI activity may play a part in the contextual identification of odors in the crayfish olfactory system.