Neuroscience
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Ischemia-reperfusion (I/R) injury often follows cardiovascular aberrations that predispose the patient to be neurological and cognitive abnormalities. Pharmacological postconditioning (pPoCo) aims to mitigate I/R origin cerebral infarction and neurobehavioral impairment. Protocatechuic acid (PCA) is a natural polyphenol possessing anti-oxidant and anti-inflammatory activities. ⋯ Histopathology revealed a decrease in total infarct area (TTC staining) and cortical neuron density by I/R surgery that was attenuated by PCA. Trigonelline antagonized beneficial effects of PCA pPoCo and attenuated Nrf2 pathway in I/R mice model. PCA pPoCo dose-dependently improves neurobehavioral functions against global I/R injury via the Nrf2 mechanism.
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In certain biologically relevant computing scenarios, a neuron "pools" the outputs of multiple independent functional subunits, firing if any one of them crosses threshold. Recent studies suggest that active dendrites could provide the thresholding mechanism, so that both the thresholding and pooling operations could take place within a single neuron. A pooling neuron faces a difficult task, however. ⋯ In a similar vein, we used a compartmental model to study how a neuron's performance at the BSP task is affected by different spine density layouts and other biological variables. We found BSP performance was optimized when dendrites have (1) a decreasing spine density gradient (true for many types of pyramidal neurons); (2) low-to-medium resistance spine necks; (3) strong NMDA currents; (4) fast spiking Na+ channels; and (5) powerful hyperpolarizing inhibition. Our findings provide a normative account that links several neuronal properties within the context of a behaviorally relevant task, and may provide new insights into nature's subtle strategies for optimizing the computing capabilities of neural tissue.