Movie 1 (MPEG4, 1.2MB) STII medaka, 12 dpf, left lateral view. Lacking dermal and visceral pigmentation, internal organs are readily visible through the body wall, and amenable to in vivo observation/imaging. Note peristalsis in the gut on a temporal scale. Liver (L), Gut (Gt), Otic Vesicle (Ov), Spleen (Sp), Air/Swim Bladder (AB), Heart (H)
Movie 2 (MOV, 4.2 MB) Example of 3D reconstruction of hepatic parenchyma from in vivo confocal image stack: bile preductules and preductular epithelial cells, STII medaka, 24 dpf. Shown are the 3D characteristics of bile preductular epithelia (BPDEC) and bile preductules (BPD), the latter a unique morphological feature created by junctional complexes between hepatocytes and BPDECs. Hepatocytes, which occupy the negative/empty space, are not rendered for visual clarity. A canaliculus (C, green) is shown joining a bile preductule (BPD, green). The background grayscale image is a single optical section from a confocal image stack. To our knowledge this was the first rendering of this bile preductule junctional complex in 3D, the evaluation of which provided novel insights into parenchymal organization. The movie given here, extracted from an Amira 3D reconstruction, is limited to rotation in a single plane. Actual 3D reconstructions can be rotated in any plane, at virtually any magnification, allowing detailed study of hepatobiliary structure/function relationships.
Movie 3 (MOV, 8MB) Example of 3D reconstruction of parenchyma from in vivo confocal image stacks: relationship of sinusoids to intrahepatic biliary passageways, STII medaka, 30 dpf. Sinusoids (S) are denoted in red, canaliculi (C) in green. All space between sinusoids and surrounding canaliculi (empty) is hepatocellular space, not rendered for visual clarity. Morphometric and volumetric analyses of 3D reconstructions assisted elucidation of parenchymal architecture, and relationship of canaliculi to sinusoids. These types of investigations revealed medaka hepatic parenchyma to be more akin to a muralium like structure (as opposed to tubular architecture). Grayscale confocal image can be seen in the background. The movie given here, extracted from an Amira 3D reconstruction, is limited to rotation in a single plane. Actual 3D reconstructions can be rotated in any plane, at virtually any magnification, allowing detailed study of hepatobiliary structure/function relationships.
Movie 4 (MOV, 5.5 MB) Example of 3D reconstruction of parenchyma from in vivo confocal image stacks: relationship of sinusoids to intrahepatic biliary passageways, STII medaka, 30 dpf. Sinusoids (S) are denoted in red, canaliculi (C) in green. All space between sinusoids and surrounding canaliculi (empty) is hepatocellular space, not rendered for visual clarity. Morphometric and volumetric analyses of 3D reconstructions assisted elucidation of parenchymal architecture, and relationship of canaliculi to sinusoids. These types of investigations revealed medaka hepatic parenchyma to be more akin to a muralium like structure (as opposed to tubular architecture). Grayscale confocal image can be seen in the background. The movie given here, extracted from an Amira 3D reconstruction, is limited to rotation in a single plane. Actual 3D reconstructions can be rotated in any plane, at virtually any magnification, allowing detailed study of hepatobiliary structure/function relationships.
Movie 5 (MOV, 4.6MB) Example of 3D reconstruction of hepatobiliary architecture from in vivo confocal image stack: sinusoids and parenchymal architecture, STII medaka, 30 dpf. Sinusoids (S) are denoted in red. All space between sinusoids (empty) is hepatocellular space, not rendered for visual clarity. Morphometric and volumetric analyses of 3D reconstructions allowed elucidation of parenchymal architecture, and revealed medaka parenchyma more akin to a muralium like structure (as opposed to tubular architecture). Background grayscale image is a single frame from a confocal image stack from which the 3D model was generated. The movie given here, extracted from an Amira 3D reconstruction, is limited to rotation in a single plane. Actual 3D reconstructions can be rotated in any plane, at virtually any magnification, allowing detailed study of hepatobiliary structure/function relationships. STII medaka, 30 dpf.
These findings, which describe similarities and differences between mammalian and medaka hepatobiliary systems in response to a reference hepatotoxicant (ANIT), in conjunction with our prior in vivo work characterizing normalcy, illustrate the importance of our comparative understanding of the vertebrate liver, and the significance of this understanding on the interpretation and communication of xenobiotic induced injury in piscine livers. From these and previous findings it is apparent that appreciating the spectrum of responses of the piscine liver to xenobiotics that target the this organ system, particularly in a comparative sense, requires more attention to bile preductular epithelial cells, bile preductules, and their relationship to the interconnected intrahepatic biliary network. This is becoming increasingly important given that toxicity screening in embryos and eleutheroembryos is a key factor in the regulatory evaluation of chemicals of environmental concern (e.g. REACh protocol; regulatory framework for Registration, Evaluation, Authorization and Restriction of Chemicals) (ECHA 2007), and that the liver is a key target organ of toxicity.
Our in vivo xenobiotic response work also showed for the first time in vivo evaluation of toxicity in the STII medaka, and demonstrate the ability to study and image, with high resolution, normalcy and toxicity in living individuals; a valuable diagnostic and investigatory tool. Given the described coupling of in vivo and ex vivo investigations, this suggests the future ability to integrate molecular mechanisms of disease and toxicity to system level phenotypes, a current research aim in this laboratory. (End)