神经损伤与修复
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Figure 1｜NH and EE treatments display lifelong protective effects against neurodegeneration in the rat hippocampus.
Postnatal tactile and enriched sensory stimulation and recovery from brain damage: Altogether, massage therapy in preterm human infants, and enriched sensory stimulation (NH, EE) in rodents, appear to display potent and long-term positive effects on development, brain development and neuroplasticity. Do such neuroplasticity effects extend to positive neuroregeneration effects in brain-injured subjects? As said above, both NH and EE treatments are capable of preventing the age-related neuronal degeneration in the hippocampus (Figure 1), and this goes along with NH and EE complete prevention of age-related spatial learning/memory deficits (Meaney et al., 1988; Fernández-Teruel et al., 1997; Figure 1). It has been proposed that a likely mechanism mediating NH and EE prevention of age-related hippocampus-dependent impairments might involve the attenuation of the ‘‘glucocorticoid-glutamate-calcium’’ neurotoxic cascade (Fernández-Teruel et al., 2002). But, are these early sensory-enriched treatments able to reverse or attenuate neuronal damage produced by brain insults? Brain injury induced by perinatal hypoxia-ischemia (HI) is an early brain insult that is directly related to perinatal morbidity and various neuro-developmental deficits, and preterm infants are at increased risk of HI injury. Male human infants are more vulnerable than females to brain insult. In one study, male and female mice were submitted to HI (PND7) and NH treatment (PND1-21). Sensorimotor, behavioral, cognitive and brain neuropathological measures were taken at PND70–90 (Muntsant et al., 2019). Male mice appeared to be more vulnerable to HI-induced long-term memory impairment, and NH attenuated such a deficit more clearly in males than in females (Muntsant et al., 2019). NH treatment significantly attenuated HI-induced neuropathology in several brain regions (hippocampus, thalamus, caudate/putamen, neocortex, corpus callosum) in males, whereas the effect of NH was also significant but of lower magnitude in females (corpus callosum and neocortex). However, the neuropathological HI effects were statistically similar between both sexes, which could be because the authors did not use unbiased stereological quantification procedures (Muntsant et al., 2019).