LOCALIZATION OF INTERLEUKIN-1-BETA MESSENGER-RNA IN THE CEREBRAL GANGLION OF THE PROTOCHORDATE, STYELA-PLICATA

There is evidence that interleukin 1 beta (IL-1 beta) plays an importa nt role in several biological functions in mammals where it is synthes ized by cells of haematological, dermal and neural origin. Moreover, p roduction of cytokine-like molecules has been demonstrated in some blo od cells of non-mammalian vertebrates and invertebrates in which also nerve cells are demonstrated to be IL-1 beta immunoreactive. The purpo se of the present study is to demonstrate the IL-1 beta mRNA expressio n in nerve cells of the ascidian Styela plicata by use of non-isotopic in situ hybridization technique. The expression of IL-1 beta messenge r was demonstrated in monopolar neurons in the cortical layer of the c erebral ganglion. The neuronal expression of cytokine-like molecules i n tunicates suggests that IL-1 beta is an ancestral and functionally c onserved molecule, and that a neuroimmune axis appeared early during t he metazoan phylogeny. (C) 1997 Elsevier Science Ireland Ltd.