Postnatal development stages

Schuller U, Kho AT, Zhao Q, Ma Q, Rowitch DH (2006) Cerebellar transcriptome reveals cell-type and stage-specific expression during postnatal development and tumorigenesis. Mol CeU... 

Fride, E. (2008). Multiple roles for the endocannabinoid system during the earliest stages of life Pre-and postnatal development. J. Neuroendocrinol. 20(Suppl. 1), 75-81. 

Janeczko, K., Spatiotemporal patterns of the astroglial proliferation in the rat brain injured at the postmitotic stage of postnatal development. A combined immunocy-tochemical and autoradiographic study, Brain Res., 485, 236, 1989. 

This report has briefly summarized what we now know about thyroid hormone transport to the central nervous system. The data are still sketchy and much remains to be done. Obviously the brain is a complex organ and major differences in thyroid hormone transport and metabolism are to be expected in its constituent parts, so study of different brain regions as well as different cell types is required. We also need to distinguish between findings in the mature brain and those during fetal and postnatal development. Thyroid hormones play a very different role in these stages of the organism, and possible variations in hormone delivery to cells may contribute to these differences. Finally, in the malnutrition that often accompanies iodine deficiency, we need to ask whether PA synthesis in the choroid plexus is compromised, as it is in the liver. If so, important effects in thyroid hormone delivery to the brain may be expected. 

As discussed earlier in the chapter, embiyonic tissues and organs of several animal models have exhibited traces of liquid-crystals during embryonic development stage that did not persist postnatally. In liver and yolk sac, massive liquid-ciystals are present from embryogenesis to early post-natal development. In this section, we will summarize the characteristics of liquid-crystals in different tissues in comparison to the liquid-crystals found in human diseases (Table 1). 

These components would normally be evaluated in a rodent species (preferably rats) and, in addition, embryo-fetal development would be evaluated in a second species, typically the rabbit. The most probable option in the ICH guideline is the case where three rodent studies would be conducted that separately addressed each of the components listed above. These study designs are described below. The day of insemination or detection of evidence of mating is considered Day 0 of gestation and the day of birth is considered postpartum and postnatal Day 0. Figure 8.1 presents line charts for the ICH Stage-Study Designs. 

Col Hal null mice have fibril diameter abnormalities in the early postnatal stage but the adult showed no significant differences. Type XIV collagen might function early in development regulating the entry of fibril intermediates into lateral fibril growth. ... 

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