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The postnatal development of the human hippocampal formation establishes the time and place at which we start autobiographical memories. However, data concerning the maturation of the neurochemical phenotypes characteristic of interneurons in the human hippocampus are scarce. We have studied the perinatal and postnatal changes of the dentate gyrus (DG) interneuron populations at three rostrocaudal levels. Immunohistochemically identified neurons and fibers for somatostatin (SOM-12 and SOM-28) and neuropeptide Y (NPY) and the co-localization of SOM-28 and NPY were analyzed. In total, 13 cases were investigated from late pregnancy (1 case), perinatal period (6 cases), first year (1 case), early infancy (3 cases), and late infancy (2 cases). Overall, the pattern of distribution of these peptides in the DG was similar to that of the adult. The distribution of cells was charted, and the cell density (number of positive cells/mm(2)) was calculated. The highest density corresponded to the polymorphic cell layer and was higher at pre- and perinatal periods. At increasing ages, neuron density modifications revealed a decrease from 5 postnatal months onward. In contrast, by late infancy, two immunoreactive bands for SOM-28 and NPY in the molecular layer were much better defined. Double-immunohistochemistry showed that NPY-positive neurons co-localized with SOM-28, whereas some fibers contained only one or other of the neuropeptides. Thus, this peptidergic population, presumably inhibitory, probably has a role in DG maturation and its subsequent functional activity in memory processing.

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Since the past decade, there has been growing interest to grant nanoparticles with diffusion properties across mucosae. In this sense, the nonionic block copolymer Pluronic F127 (PF127) has emerged as a promising coating agent to formulate mucus-penetrating particles. In the journey to find efficient coating agents, researchers have focused more on the effect of the coating agent architecture rather than on the role of the physicochemical properties of the nanoparticle used as the substrate. The current knowledge about mucodiffusive particles is in general based on model-like nanoparticles, such as polystyrene or poly(lactic-co-glycolic) acid nanoparticles, but there is a lack of information about the potential of PF127 on other colloidal systems. This work aims to shed some light on this issue by selecting three oils, palm (solid), coconut (semisolid), and wheat germ (liquid), with different physicochemical properties to formulate PF127-coated nanoemulsions. The obtained nanoemulsions were characterized, and their colloidal stability was tested. Their diffusion capacity was determined by particle tracking after challenging the nanoemulsions across an intestinal porcine mucus layer. In accordance with the evidence of model-like nanoparticles, our results state that PF127 allows mucodiffusion, but its effectiveness as a coating agent clearly depends on the physicochemical properties of the nanostructure core over which PF127 is placed. Among other physicochemical properties, the results certainly showed that the hydrophobic character of the nanostructure core emerges as a critical factor in the formulation of successful PF127 coatings.

The prevalence of neurodegenerative disorders is increasing; however, an effective neuroprotective treatment is still remaining. Nutrition plays an important role in neuroprotection as recently shown by epidemiological and biochemical studies which identified food components as promising therapeutic agents. Neuroprotection includes mechanisms such as activation of specific receptors, changes in enzymatic neuronal activity, and synthesis and secretion of different bioactive molecules. All these mechanisms are focused on preventing neuronal damage and alleviating the consequences of massive cell loss. Some neuropathological disorders selectively affect to particular neuronal populations, thus is important to know their neurochemical and anatomical properties in order to design effective therapies. Although the design of such treatments would be specific to neuronal groups sensible to damage, the effect would have an impact in the whole nervous system. The difficult overcoming of the blood brain barrier has hampered the development of efficient therapies for prevention or protection. This structure is a physical, enzymatic, and influx barrier that efficiently protects the brain from exogenous molecules. Therefore, the development of new strategies, like nanocarriers, that help to promote the access of neuroprotective molecules to the brain, is needed for providing more effective therapies for the disorders of the central nervous system (CNS). In order both to trace the success of these nanoplatforms on the release of the bioactive cargo in the CNS and determinate the concentration at trace levels of targets biomolecules by analytical chemistry and concretely separation instrumental techniques, constitute an essential tool. Currently, these techniques are used for the determination and identification of natural neuroprotective molecules in complex matrixes at different concentration levels. Separation techniques such as chromatography and capillary electrophoresis (CE), using optical and/or mass spectrometry (MS) detectors, provide multiples combinations for the quantitative and qualitative analysis at basal levels or higher concentrations of bioactive analytes in biological samples. Bearing this in mind, the development of food neuroprotective molecules as brain therapeutic agents is a complex task that requires the intimate collaboration and engagement of different disciplines for a successful outcome. In this sense, this work reviews the new advances achieved in the area toward a better understanding of the current state of the art and highlights promising approaches for brain neuroprotection.