Many phosphorylated extracellular signal-regulated kinase (pERK)-immunoreactive (IR) cells are expressed in the trigeminal spinal subnucleus caudalis (Vc), upper cervical spinal cord (C1-C2), nucleus tractus solitarii (NTS) and paratrigeminal nucleus (Pa5) after @entity2951 injection into the whisker pad (WP), masseter muscle (MM), @entity121 ( @entity121 ) or sternohyoideus muscle (SM). The pERK-IR cells also showed NeuN immunoreactivity, indicating that ERK phosphorylation occurs in neurons. The pERK-IR cells were significantly reduced after intrathecal injection of @entity19871 inhibitor @entity4286 . The pERK-IR cells expressed bilaterally in the Vc and C1-C2 after @entity2951 injection into the unilateral @entity121 or SM, whereas unilaterally in the Vc and C1-C2 after unilateral WP or MM injection. After @entity2951 injection into the WP or MM, the pERK-IR cell expression in the Vc was restricted rostrocaudally within a narrow area. However, the distribution of pERK-IR cells was more wide spread without a clear peak in the Vc and C1-C2 after @entity2951 injection into the @entity121 or SM. In the NTS, the unimodal pERK-IR cell expression peaked at 0-720 m rostral from the obex following @entity2951 injection into WP, MM, @entity121 or SM. In the ipsilateral Pa5, many pERK-IR cells were observed following @entity2951 injection into the SM. The number of swallows elicited by distilled water administration was significantly smaller after @entity2951 injection into the WP, MM or @entity121 but not SM compared to that of vehicle-injected @entity35 . Various noxious inputs due to the masticatory or swallowing-related @entity121 may be differentially involved in @entity925 and swallowing reflex activity.

Organization of pERK-immunoreactive cells in trigeminal spinal nucleus caudalis, upper cervical cord, NTS and Pa5 following @entity2951 injection into masticatory and swallowing-related muscles in XXXX .

@entity35 :: ('10116', 'Species') :: ['rats'] @entity2951 :: ('MESH:D002211', 'Chemical') :: ['capsaicin'] @entity19871 :: ('170851;58960', 'Gene') :: ['MEK 1/2'] @entity4286 :: ('MESH:C093973', 'Chemical') :: ['PD98059'] @entity925 :: ('MESH:D063806', 'Disease') :: ['muscle pain'] @entity121 :: ('MESH:D009135', 'Disease') :: ['DM', 'muscle inflammation', 'digastric muscle']
@entity35 :: (10116,Species) :: ['rats']
