Figure 9

Mechanisms underlying neuron-glia interaction in trigeminal ganglia. Satellite glial cells ensheath trigeminal neurons constituting a functional unit into the trigeminal ganglion, as represented in the schematic. It has been demonstrated (dashed arrows) that trigeminal neurons release CGRP and NO within the ganglia during activation. CGRP was shown to increase IL1β secretion by trigeminal satellite cells (dashed arrows). Thus, IL-1β and the NO donor DETA/NO (red) were tested on satellite cells. DETA/NO better mimics neuronal NO release generated by nNOS. Both stimuli increase glial COX activity, even though via different molecular mechanisms (arrows). Conditioned media harvested from glial cells challenged with both stimuli promote neuronal sensitization. Compounds exogenously added to trigeminal satellite cells in different experimental paradigms are indicated in red.