NORADRENERGIC AND PEPTIDERGIC INNERVATION OF LYMPHOID ORGANS IN THE BELUGA, DELPHINAPTERUS-LEUCAS - AN ANATOMICAL LINK BETWEEN THE NERVOUS AND IMMUNE-SYSTEMS
Ta. Romano et al., NORADRENERGIC AND PEPTIDERGIC INNERVATION OF LYMPHOID ORGANS IN THE BELUGA, DELPHINAPTERUS-LEUCAS - AN ANATOMICAL LINK BETWEEN THE NERVOUS AND IMMUNE-SYSTEMS, Journal of morphology, 221(3), 1994, pp. 243-259
The presence of peptidergic and noradrenergic sympathetic nerve fibers
in specific compartments of both primary and secondary lymphoid organ
s of the rodent is well established. These nerve fibers directly conta
ct lymphocytes and macrophages, as well as vascular and trabecular smo
oth muscle. We investigated the noradrenergic and neuropeptide-Y inner
vation of lymphoid organs in the cetacean, Delphinapterus leucas (belu
ga whale). The spleen, thymus, tonsil, gut-associated lymphoid tissue,
and assorted lymph nodes were collected from five belugas, obtained d
uring sanctioned hunts, and processed for catecholamine fluorescence h
istochemistry and for tyrosine hydroxylase and neuropeptide-Y immunocy
tochemistry. Innervation studies revealed fluorescent nerve fibers, ty
rosine hydroxylase, and neuropeptide-Y positive nerve fibers in parenc
hymal lymphoid compartments, where they were closely associated with c
ells of the immune system, and in vascular and trabecular compartments
. In lymphoid zones, tyrosine hydroxylase and neuropeptide-Y positive
nerve fibers were observed in the periarteriolar lymphatic sheath and
marginal zone of the spleen; in the outermost portion of the cortex, t
he corticomedullary zone, and medulla of the lymph nodes; in the paraf
ollicular zones, and diffuse lymphocyte layer below the epithelium of
the tonsil; in the outermost portion of some thymic lobules; and in th
e lamina propria of the gut. These findings are similar to those descr
ibed for other mammals and substantiate an anatomical link between the
nervous and immune systems in the beluga, whereby central nervous sys
tem activity may influence autonomic outflow to lymphoid organs and ef
fect immunologic reactivity. (C) 1994 Wiley-Liss, Inc.