CHEMOGENETIC MODULATION OF SATELLITE GLIAL CELLS IN FEMALE MICE REGULATES MIGRAINE-LIKE BEHAVIOURAL FEATURES

Satellite glial cells (SGCs) are the most abundant cells in sensory and parasympathetic ganglia. They maintain close interactions with neurons through neuron–glia communication and are essential for preserving a proper neuronal environment. Recently, some studies have associated SGCs of the trigeminal ganglion (TG) with migraine pathophysiology and progression.
We hypothesized that SGCs modulation plays a role in migraine pathophysiology.
To modulate TG SGCs, 2.0 µL of AAV-6/2-mFabp7-hM3D(Gq)_mCherry and AAV-6/2-mFabp7-hM4D(Gi)_mCherry were stereotactically injected into the left and right TG at three different coordinates in C57BL/6J female mice. The activating vector was used in naive mice to observe the effects of SGCs activation. The inactivating vector was injected prior to the induction of the chronic migraine mice model, which was achieved with nitroglycerin (10mg/kg) injections every other day over nine days.
Migraine-like behavioural features were assessed using orofacial mechanical allodynia von Frey test and light aversion test; and depression-like features using open field and tail suspension tests. Data were analyzed using mixed-effects models with correction for multiple comparisons.
SGCs activation increased orofacial mechanical allodynia when compared to baselines (P=0.0025). This increase was also seen in the chronic migraine model (P=0.0046) and was attenuated after SGCs inactivation (P>0.01). No differences were observed in light aversion, open field and tail suspension tests.
SGCs modulate orofacial mechanical allodynia, supporting a role for peripheral glia in migraine. Further studies and refinement of existing methodologies are needed to clarify the contribution of these cells within sensory ganglia and to migraine pathophysiology.