Pain
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Comparative Study
Social networks and pain interference with daily activities in middle and old age.
Social networks have emerged as important in the development and progression of disability in aging cohorts. We have previously reported that pain that interferes with daily activities is common and increases incrementally from middle age into later life. The current study has investigated whether pain interference in this age group is related to social network characteristics. 5215 community-dwelling adults aged 50 years and over participating in the North Staffordshire Osteoarthritis Project (NorStOP) and identified as currently experiencing pain formed the sample for the present analysis. ⋯ The associations with close friends and children were reduced but remained significant after adjusting for sociodemographic factors. The association with close friends became non-significant after adjusting for depression suggesting this may form part of the pathway linking close friends networks and pain interference. Pain-related interference shows similar associations with social networks as all-cause disability and may benefit similarly from a public health perspective.
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Comparative Study
The effects of acute and chronic restraint stress on activation of ERK in the rostral ventromedial medulla and locus coeruleus.
Extracellular signal-regulated kinase (ERK) is a key molecule in numerous cellular and physiological processes in the CNS. Exposure to stressors causes substantial effects on the perception and response to pain. The rostral ventromedial medulla (RVM) and the locus coeruleus (LC) play crucial roles in descending pain modulation system. ⋯ Protein levels of tryptophan hydroxylase were significantly increased in the RVM region in the 3-week restraint rats. On the other hand, the chronic restraint stress significantly decreased p-ERK-IR in the LC [P<0.05]. These findings suggest that chronic restraint stress-induced activation of ERK in the RVM and the suppression in the LC may be involved in the modulation of the pain threshold by chronic stress.