title: Functional crosstalk in culture between macrophages and trigeminal sensory neurons of a mouse genetic model of migraine.
abstract: BACKGROUND
  Enhanced activity of trigeminal ganglion neurons is thought to underlie neuronal sensitization facilitating the onset of chronic pain attacks, including migraine. Recurrent headache attacks might establish a chronic neuroinflammatory ganglion profile contributing to the hypersensitive phenotype. Since it is difficult to study this process in vivo, we investigated functional crosstalk between macrophages and sensory neurons in primary cultures from trigeminal sensory ganglia of wild-type (WT) or knock-in (KI) mice expressing the Cacna1a gene mutation (R192Q) found in familial hemiplegic migraine-type 1. After studying the number and morphology of resident macrophages in culture, the consequences of adding host macrophages on macrophage phagocytosis and membrane currents mediated by pain-transducing P2X3 receptors on sensory neurons were examined.
  
  
  RESULTS
  KI ganglion cultures constitutively contained a larger number of active macrophages, although no difference in P2X3 receptor expression was found. Co-culturing WT or KI ganglia with host macrophages (active as much as resident cells) strongly stimulated single cell phagocytosis. The same protocol had no effect on P2X3 receptor expression in WT or KI co-cultures, but it largely enhanced WT neuron currents that grew to the high amplitude constitutively seen for KI neurons. No further potentiation of KI neuronal currents was observed.
  
  
  CONCLUSIONS
  Trigeminal ganglion cultures from a genetic mouse model of migraine showed basal macrophage activation together with enhanced neuronal currents mediated by P2X3 receptors. This phenotype could be replicated in WT cultures by adding host macrophages, indicating an important functional crosstalk between macrophages and sensory neurons.
authors.affiliation: Department of Neuroscience and Italian Institute of Technology Unit, International School for Advanced Studies (SISSA), Via Bonomea 265, Trieste, 34136, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Franceschini
authors.forename: Asha
authors.initials: A
authors.lastname: Nair
authors.forename: Tanja
authors.initials: T
authors.lastname: Bele
authors.forename: Arn Mjm
authors.initials: AM
authors.lastname: van den Maagdenberg
authors.forename: Andrea
authors.initials: A
authors.lastname: Nistri
authors.forename: Elsa
authors.initials: E
authors.lastname: Fabbretti
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D020746:Calcium Channels, L-Type / Q000235:genetics; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002450:Cell Communication / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008840:Microfilament Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D018408:Patch-Clamp Techniques; D010587:Phagocytosis / Q000187:drug effects / Q000235:genetics; D058477:Receptors, Purinergic P2X3 / Q000235:genetics / Q000378:metabolism; D011984:Sensory Receptor Cells / Q000502:physiology*; D012668:Trigeminal Ganglion / Q000166:cytology*; D014404:Tubulin / Q000378:metabolism
chemical_list: C491049:Aif1 protein, mouse; C514350:CACNA1C protein, mouse; D020746:Calcium Channels, L-Type; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins; D058477:Receptors, Purinergic P2X3; D014404:Tubulin; C462941:beta3 tubulin, mouse; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate