Brain research
-
Subarachnoid hemorrhage (SAH) which is mostly caused by aneurysm rupture causes a lot of death every year. Convincing evidence can be made that inflammation contributes to the poor outcome caused by SAH. Toll like receptors (TLRs), nuclear factor-kappaB (NF-κB), Interleukin 1β (IL-1β) and tumor necrosis factor-α (TNF-α) are involved in the damaging inflammation process after SAH. ⋯ Our results demonstrated MyD88 expression was increased after SAH, and peaked on day 1 and day 5, which showed a parallel time course to the up-regulation of IL-1β, there was a highly positive relationship between them. Immunohistochemistry and immunofluorescence results indicated up-regulated MyD88 was mainly located in neurons while over expressed MyD88 could also be found in astrocytes and microglia. These results might have important implications during the administration of specific MyD88 antagonists in order to prevent or reduce inflammatory response following SAH.
-
Impaired spinal GABAergic inhibitory function is known to be pivotal in neuropathic pain (NPP). At present, data concerning time-dependent alterations in cell type and cell death in the spinal dorsal horn are highly controversial, likely related to the experimental NPP model used. In this study, we examined the expression of autophagy using a L5 spinal nerve ligation (SNL)-induced neuropathic pain rat model. ⋯ Double immunohistochemical analysis further confirmed increases in LC3 and Beclin 1 in mostly neurons and a few astrocytes following SNL. LC3 and Beclin 1 expressions were upregulated in GABAergic interneurons of spinal dorsal horn after SNL, while the loss of GABAergic interneurons did not change significantly. Our results suggest that autophagic disruption in GABAergic interneurons and astrocytes following peripheral nerve injury might be involved in the induction and maintenance of neuropathic pain.
-
To study the effects of 2,2',4,4',5,5'-hexa-brominated diphenyl ether (BDE-153) exposure during lactation on the learning and memory abilities, spontaneous behavior and brain cells of adult rats and to elicit basic information on PBDE's developmental neurotoxicity. ⋯ Lactation exposure to BDE-153 damaged adult rats' learning and memory abilities, disrupted their spontaneous behavior (hypoactivity) and induced hippocampus neuron apoptosis.
-
Recent findings implicate the calcium-permeable transient receptor potential (TRP) melastatin subtype 2 (TRPM2) and canonical subtype 3 (TRPC3) channels in the pathogenesis of bipolar disorder (BD). As both channels are involved in calcium and oxidative stress signaling, thought to be disrupted in BD, we sought to determine the effects of elevated oxidative stress on their expression and function. Primary rat cortical neurons and astrocytes were treated with oxidative stressors for 1 (acute) and 4 days (chronic). ⋯ Unlike neurons, rotenone treatment incurred no changes in astrocyte TRPC3 levels. These findings demonstrate that TRPC3 and TRPM2 channel expression and/or function is sensitive to the redox status of rat primary neurons and that these changes are time dependent. This provides a critical mechanistic link between altered oxidative stress markers, dysfunction of these TRP channels and calcium dyshomeostasis in BD.
-
This study was done to investigate whether chronic intermittent hypoxia (CIH) induced changes in leptin and leptin receptor protein levels, and known downstream mediators of leptin receptor signaling in the carotid body. Rats were subjected to CIH (120s normoxia, 80s hypoxia) or normoxia for 8h/day to either short term (7 days) or long term CIH exposure (95 days). After both 7 and 95 days of CIH, carotid body leptin protein expression was decreased, while protein levels of the long form leptin receptor (OB-Rb) were elevated. ⋯ However, OB-Rb or Ob-R100 protein levels were not changed in the normoxic or CIH group at either time point. Furthermore, pSTAT3 protein levels were found to be significantly higher, while SOCS3 levels were significantly lower in the 95 day CIH group compared to the 7 day CIH group. Taken together, these data indicate that CIH induces changes in leptin and leptin downstream signaling proteins within the carotid bodies which may contribute to alterations in carotid chemoreceptor sensitivity.