A potent leukocyte chemotactic and activating cytokine, interleukin-8 (IL-8), is produced by numerous types of cells in response to inflammatory stimuli. Accumulating evidence indicate that the transcription of IL-8 gene requires the activation of either the combination of NF-kappa B and AP-1 or that of NF-kappa B and NF-IL6, depending on the type of cells. Alternatively, the activation of NF-kappa B is indispensable for IL-8 gene activation in any types of cells examined. On the other hand, an immunosuppressant, FK506, and a glucocorticoid inhibit the gene transcription as well as the production of IL-8. Molecular analyses of IL-8 gene repression by these agents revealed that both affected the activity of the transcription factor(s) bound to the NF-kappa B site, albeit in different ways, thereby suppressing IL-8 gene transcription. Collectively, IL-8 production seems to be controlled mainly at the activation step of the transcription factor(s) bound to the NF-kappa B site.

Various hypotheses regarding the homology of the teleostean telencephalon with that of other vertebrates have been proposed to date. However, a firm conclusion on this issue has yet to be drawn. We propose here a new hypothesis with a new eversion model. Our hodological data and the analysis of dorsal telencephalic organization in adult cyprinids suggest that: (1) the area dorsalis pars posterior corresponds to the lateral pallium; (2) ventral region of area dorsalis pars lateralis to the medial pallium; (3) pars medialis, dorsal region of pars lateralis, pars dorsalis, and pars centralis of the area dorsalis to the dorsal pallium, and (4) nucleus taenia to the ventral pallium. We propose in a three dimensional model that the eversion process occurs not only dorsolaterally but also caudolaterally. We consider that the caudally directed component dominates for ventral zones of the pallium, or the lateral and ventral pallia; and the periventricular surface of these zones shift caudally, laterally, and then rostrally in teleosts with pronounced telencephalic eversion. This new model fits well with the putative homology based on hodology and the organization of telencephalic divisions in the adult brain.

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Fiber connections of the lateral valvular nucleus were investigated in a percomorph teleost, the tilapia (Oreochromis niloticus), by tract-tracing methods. Following tracer injections into the lateral valvular nucleus, neurons were labeled in the ipsilateral dorsal part of dorsal telencephalic area, corpus glomerulosum pars anterior, dorsomedial thalamic nucleus, central nucleus of the inferior lobe, mammillary body, semicircular torus, valvular and cerebellar corpus, in the bilateral rostral regions of the central part of dorsal telencephalic area, dorsal region of the medial part of dorsal telencephalic area, habenula, anterior tuberal nucleus, posterior tuberal nucleus, and spinal cord, and in the contralateral lateral funicular nucleus. Labeled fibers and terminals were found in the ipsilateral cerebellar corpus and bilateral valvula of the cerebellum. Tracers were injected into portions of the telencephalon, pretectum, inferior lobe, and cerebellum to confirm reciprocally connections with the lateral valvular nucleus and to determine afferent terminal morphology in the lateral valvular nucleus. Telencephalic fibers terminated mainly in a dorsolateral portion of the lateral valvular nucleus. Terminals from the corpus glomerulosum pars anterior, central nucleus of the inferior lobe, and mammillary body showed more diffuse distributions and were not confined to particular portions of the lateral valvular nucleus. Labeled terminals in the lateral valvular nucleus were cup-shaped or of beaded morphology. These results indicate that the lateral valvular nucleus receives projections from various sources including the telencephalon, pretectum, and inferior lobe to relay information to the valvular and cerebellar corpus. In addition, the corpus glomerulosum pars anterior in tilapia is considered to be homologous to the magnocellular part of superficial pretectal nucleus in cyprinids.

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