Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Blindness leads to a major reorganization of neural pathways associated with touch. Because incoming somatosensory information influences motor output, it is plausible that motor plasticity occurs in the blind. In this work, we evaluated this issue at the peripheral level in enucleated rats. Whisker muscles in enucleated rats 160 days of age or older showed increased cytochrome oxidase activity, capillary density, motor plate size, and amplitude of evoked field potentials as compared with their control counterparts. Such differences were not observed at ages 10 and 60 days, the capillary density was the exception being greater in the enucleated rat at the latter age. Interestingly, there was a trend to increased neurotrophin-3 concentrations in the whisker pads of enucleated rats throughout postnatal development. Our results show that neonatal enucleation leads to late onset plasticity of the whisker's motor system.
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PMID:Late onset muscle plasticity in the whisker pad of enucleated rats. 1883 91

Prenatal stress exposure causes long-lasting impairments of the behavioral and neuroendocrine responses to later stressors of the offspring. Although mechanisms underlying these effects remain largely unknown, abnormalities in the neuronal plasticity might be responsible for neurobiological alterations. This study used the whisker-to-barrel pathway as a model system to investigate the effects of prenatal stress on lesion-induced plasticity of neurons. Pregnant rats were subjected to immobilization stress during the trigeminal neurogenesis period, corresponding to gestational days 12 to 17, for three hours a day. After birth, the middle row (C) whisker follicles of pups from the control and stressed groups were electrocauterized. Ten days later, tangentially sectioned cortical hemispheres were stained with cytochrome oxidase histochemistry to calculate the volumes of each barrel row (A-E) in both lesioned and intact sides of the cortex, using stereological methods. The adrenal to body weight ratios were significantly increased in stressed animals, when compared to the controls. The pattern and total volume of the barrel subfield remained unaltered, but the lesion-induced map plasticity index, calculated as the D/C ratio, decreased in stressed animals. In addition, the BDNF (Brain Derived Neurotrophic Factor), NT-3 (neurotrophin-3) and the cyclic AMP response element binding protein (CREB) phosphorylation levels in tissue homogenates of the barrel cortices were measured using the ELISA method. In prenatally stressed animals, the BDNF and NT-3 levels were reduced on the lesioned side, but significant CREB activation was observed on the intact side of the barrel cortex. Taken together, the results show that prenatal stress exposure negatively affects critical period plasticity by reducing the expansion of active barrels following peripheral whisker lesion. These changes arise independent of CREB phosphorylation and appear to be mediated by reduced levels of neurotrophins.
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PMID:Lesion-induced synaptic plasticity in the somatosensory cortex of prenatally stressed rats. 2183 67

The overproduction of reactive oxygen species (ROS) and reactive nitrogen species (RNS) has been known to contribute to the pathogenesis of noise-induced hearing loss. In this study, we discovered that in BALB/c mice pretreatment with methylene blue (MB) for 4 consecutive days significantly protected against cochlear injury by intense broad-band noise for 3 h. It decreased both compound threshold shift and permanent threshold shift and, further, reduced outer hair cell death in the cochlea. MB also reduced ROS and RNS formation after noise exposure. Furthermore, it protected against rotenone- and antimycin A-induced cell death and also reversed ATP generation in the in vitro UB-OC1 cell system. Likewise, MB effectively attenuated the noise-induced impairment of complex IV activity in the cochlea. In addition, it increased the neurotrophin-3 (NT-3) level, which could affect the synaptic connections between hair cells and spiral ganglion neurons in the noise-exposed cochlea, and also promoted the conservation of both efferent and afferent nerve terminals on the outer and inner hair cells. These findings suggest that the amelioration of impaired mitochondrial electron transport and the potentiation of NT-3 expression by treatment with MB have a significant therapeutic value in preventing ROS-mediated sensorineural hearing loss.
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PMID:Attenuation of noise-induced hearing loss using methylene blue. 2476 57