We are encouraged to identify lymphocyte-specific signaling pathways leading to IRF4 activation, which potentially opens new avenues for targeting IRF4 networks for future clinical treatments. Organelles are subcellular compartments or macromolecular complexes with distinct structures and functions. As some of the most architecturally-complex cells, neurons contain some highly-specialized organelles. An obvious example is the photondetecting modified primary cilium of retinal photoreceptors. Another neuron-specific membranous organelle is the dendritic lamellar body, putatively related to dendrodendritic gap junctions in the olive. One of several organelles lacking a limiting membrane is the nematosome, a nucleolus-like cytoplasmic inclusion of unknown composition and function found in all rat noradrenergic sympathetic ganglion neurons, and in many other neural and embryonic tissues of various species. Other nemastosome-like inclusions contain proteins associated with Prothionamide synaptic plasticity and neurite outgrowth. A serendipitous observation led us to another, surprisingly large non-membranous toroidal organelle in sympathetic ganglion neurons. We call this structure the ��loukoumasome�� from the Greek loukoumas and soma. We report on its composition, its distribution amongst sympathetic ganglia and amongst subclasses of sympathetic neurons, and on its subcellular localization and relationship with other organelles. It expresses non-muscle heavy chain myosin and centrosome-associated proteins, but is not itself a modified centrosome. It is found throughout the sympathetic chain, but exclusively within neurons expressing neuropeptide Y and calbindin-D28k. It is found throughout the cell body Tedizolid Phosphate cytoplasm, as well as within the initial axon segment where it is linear rather than toroidal. Intriguingly, the loukoumasome associates with the nematosome, and with the centrosome and its primary cilium. These characteristics call to mind a dynamic organelle travelling non-randomly between cytoplasmic compartments, possibly facilitating communication between them.