Brain research
-
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 capsaicin injection into the whisker pad (WP), masseter muscle (MM), digastric muscle (DM) 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 MEK 1/2 inhibitor PD98059. ⋯ In the ipsilateral Pa5, many pERK-IR cells were observed following capsaicin injection into the SM. The number of swallows elicited by distilled water administration was significantly smaller after capsaicin injection into the WP, MM or DM but not SM compared to that of vehicle-injected rats. Various noxious inputs due to the masticatory or swallowing-related muscle inflammation may be differentially involved in muscle pain and swallowing reflex activity.
-
Autism has been hypothesized to reflect neuronal disconnection. Several recent reports implicate the key thalamic relay nuclei and cortico-thalamic connectivity in the pathophysiology of autism. Accordingly, we aimed to focus on evaluating the integrity of the thalamic radiation and sought to replicate prior white matter findings in Korean boys with high-functioning autism spectrum disorders (ASD) using Diffusion Tensor Imaging (DTI). ⋯ Our preliminary findings support evidence implicating disturbances in the thalamo-frontal connections in autism. These findings highlight the role of hypoconnectivity between the frontal cortex and thalamus in ASD.