Lamb C F, Caprio J
Department of Zoology and Physiology, Louisiana State University, Baton Rouge 70803-1725.
J Comp Neurol. 1993 Nov 15;337(3):419-30. doi: 10.1002/cne.903370306.
Many teleosts possess an enlargement of the ventral diencephalon called the inferior lobe. In ostariophysine species (e.g., carps and catfishes), this region receives ascending fibers from the primary and secondary gustatory centers in the hindbrain. Extracellular unit activity was recorded from identified nuclei in the inferior lobe of the channel catfish to characterize taste and tactile responsiveness from the different nuclei associated with gustatory projections. Taste responses (to amino acids and nucleotides) were recorded from units in the nucleus centralis (nCLI), nucleus lobobulbaris (caudal portion--nLB, rostrolateral portion--rl nLB, and parvicellular portion--nLBp), and lateral thalamic nucleus (nLT), supporting the proposed gustatory role for these nuclei. Tactile responsiveness was distinct between different nuclei in the caudal inferior lobe. Units from the nCLI and nLB had lower spontaneous activity than those from other nuclei, and typically had receptive fields including the whole extraoral body surface, ipsilaterally. Units from the rl nLB and nLBp had receptive fields, often including both oral and extraoral surfaces, bilaterally, but rl nLB receptive fields typically included the whole body, while those from nLBp units were often restricted to the head and mouth. The apparent electrophysiological distinction between these nuclei, combined with their different connectivity patterns, suggest that the gustatory nuclei in the inferior lobe of channel catfish are involved in various different sensory processing mechanisms.
许多硬骨鱼的腹侧间脑有一个称为下叶的扩大区域。在骨鳔总目鱼类（如鲤鱼和鲶鱼）中，该区域接收来自后脑初级和次级味觉中枢的上行纤维。从沟鲶下叶的特定核团记录细胞外单位活动，以表征与味觉投射相关的不同核团的味觉和触觉反应性。从中央核（nCLI）、球叶核（尾部——nLB、 rostrolateral部分——rl nLB和小细胞部分——nLBp）以及外侧丘脑核（nLT）的单位记录到对氨基酸和核苷酸的味觉反应，支持了这些核团所提出的味觉作用。尾部下叶不同核团之间的触觉反应性有所不同。来自nCLI和nLB的单位比其他核团的单位具有更低的自发活动，并且通常具有包括同侧整个口外体表的感受野。来自rl nLB和nLBp的单位具有双侧感受野，通常包括口内和口外表面，但rl nLB的感受野通常包括整个身体，而nLBp单位的感受野通常仅限于头部和口部。这些核团之间明显的电生理差异，加上它们不同的连接模式，表明沟鲶下叶的味觉核团参与了各种不同的感觉处理机制。
