Clusters of nerve cell bodies enclosed within a common connective tissue envelope in the spinal ganglia of the lizard and rat

Abstract

A careful search for groups of nerve cell bodies enclosed within a common connective envelope was made in the spinal ganglia of the lizard and rat using a serial-section technique. Nerve cell bodies sharing a common connective envelope were found to be more common in the lizard (9.4%) than in the rat (5.6%). These nerve cell bodies were arranged in pairs, or, less frequently, in groups of three. At times, they appeared to be in immediate contact, with no intervening satellite cells; at others, they remained separated from one another by a satellite cell sheet. The clusters of nerve cell bodies enclosed within a common connective envelope probably result from the arrest of developmental processes in the spinal ganglion. It is possible that, as a result of the cell arrangement here described, certain neurons electrically influence other sensory neurons at the level of the ganglion.

Satellite glial cells in sensory ganglia: from form to function

“…These cells have been studied ultrastructurally in detail in sensory ganglia of various species [102,109,[126][127][128]130]. Pannese's 1981 monograph [126] on SGCs is an essential reading on this topic.…”

“…These units are separated by regions containing connective tissue. In some cases (5.6% in rat DRG) neurons form small groups containing two to three cells that are enclosed in a common connective tissue space [130]. These groups, or dclustersT, are more prevalent in young animals [131].…”

“…These groups, or dclustersT, are more prevalent in young animals [131]. The neurons in the cluster are in most cases separated from each other by SGC sheet, but occasionally this sheet is missing [130]. The SGC envelope usually consists of flat processes that lie close to the neuronal plasma membrane.…”

An Approach to Identify Nerve Injury-Evoked Changes that Contribute to the Development or Protect Against the Development of Sustained Neuropathic Pain

“…Each soma is completely surrounded by a layer of satellite glia cells ( Figure 1); and together the soma and satellite glia cells form a single anatomical and functional unit (Hanani, 2005;Pannese, 1981). These individual units can have one to three neuronal somata, and occasionally some of the somata within a unit are not surrounded by satellite glia cells (Pannese et al, 1991). The units are in turn separated by areas of connective tissue (Pannese et al, 1991).…”

“…These individual units can have one to three neuronal somata, and occasionally some of the somata within a unit are not surrounded by satellite glia cells (Pannese et al, 1991). The units are in turn separated by areas of connective tissue (Pannese et al, 1991). Following nerve injury satellite glial cells, as their glia counterparts in the CNS, undergo functional changes (release of cytokines and neurotrophins, changes in neurotransmitter-scavenging capacity) and hence they may also contribute to the initiation and maintenance of chronic pain (Gosselin et al, 2010;McMahon and Malcangio, 2009;Milligan and Watkins, 2009;Romero-Sandoval et al, 2008;Scholz and Woolf, 2007;Takeda et al, 2009;Watkins et al, 2001;Watkins and Maier, 2002).…”