Figures & data
Figure 1. The blood–brain barrier (BBB). Molecules cross the BBB either transcellulary or paracellularly between the cells through the junctions.
Figure 2. Schematic illustration for the time-course of BBB development. Modified from ref. Citation6.
Figure 3. The blood-testis barrier (BTB) is formed by tight junction protein between Sertoli cells.
Figure 4. A simplified diagram illustrating the morphological differences between the blood‐testis barrier (BTB) and the blood‐brain barrier (BBB). (A) In the BTB, tight junctions (TJs) coexist with basal ectoplasmic specializations (ES), basal tubulobulbar complexes (TBC), and desmosome‐like junctions. (B) In the BBB TJs are restricted to the apical surface of the endothelium, sealing the intercellular space, with adherens junctions (AJ) located immediately below. Modified from ref. Citation30.
Figure 5. Microbial impact on host physiology. Microbiota in the intestinal tract exerts profound effects on host physiology, both locally and at distant sites. Locally, these bacteria enhance gut immunity and motility as well as reducing intestinal permeability. At distant sites, such as the lungs, they regulate immune defense against viral infection. In the case of the brain, they may influence behavior by decreasing synaptic connectively and increasing anxiety and perception of pain. Moreover, they modulate hepatic metabolism in a manner that decreases energy expenditure and promote adiposity. In addition, absence of gut microbiota leads to more bone mass in association with fewer osteoclasts per surface area of bone.
