Gliocyte and synapse analyses in cerebral ganglia of the Chinese mitten crab, Eriocheir sinensis: ultrastructural study

Lab-on-Chip Microsystems for Ex Vivo Network of Neurons Studies: A Review

Increasing population is suffering from neurological disorders nowadays, with no effective therapy available to treat them. Explicit knowledge of network of neurons (NoN) in the human brain is key to understanding the pathology of neurological diseases. Research in NoN developed slower than expected due to the complexity of the human brain and the ethical considerations for in vivo studies. However, advances in nanomaterials and micro-/nano-microfabrication have opened up the chances for a deeper understanding of NoN ex vivo, one step closer to in vivo studies. This review therefore summarizes the latest advances in lab-on-chip microsystems for ex vivo NoN studies by focusing on the advanced materials, techniques, and models for ex vivo NoN studies. The essential methods for constructing lab-on-chip models are microfluidics and microelectrode arrays. Through combination with functional biomaterials and biocompatible materials, the microfluidics and microelectrode arrays enable the development of various models for ex vivo NoN studies. This review also includes the state-of-the-art brain slide and organoid-on-chip models. The end of this review discusses the previous issues and future perspectives for NoN studies.

Ultrastructure of telocytes, a new type of interstitial cells in the myocardium of the Chinese giant salamander (Andrias davidianus)

Telocytes (TCs) are new interstitial cells, and they are involved in tissue regeneration, particularly in heart. Therefore, TCs are suggested to be promising cells in regenerative medicine. However, the information of location structural characteristics and functions of TCs is still limited. In this study, cardiac TCs of the Chinese giant salamanders (Andrias davidianus) were identified by transmission electron microscopy. TCs were located in the interstitium between cardiomyocytes (CM). TCs possessed distinctive ultrastructural characteristics, including one to two very long and thin moniliform telopodes (Tps), emerging points from the cell body, caveolae, dichotomous branchings, labyrinthic systems, neighbouring exosomes and homocellular contacts between Tps. TCs/Tps were frequently observed in close proximity to cardiomyocytes. Moreover, Tps established hetero-cellular contacts with cardiomyocytes. Our results confirm the presence of TCs in the myocardium of the A. davidianus. This will help us to better understand roles of TCs in amphibian hearts.

Histochemistry as a versatile research toolkit in biological research, not only an applied discipline in pathology

The impressive progress of histochemistry over the last 50 years has led to setting up specific and sensitive techniques to describe dynamic events, through the detection of specific molecules in the very place where they exist in live cells. The scientific field where histochemistry has most largely been applied is histopathology, with the aim to identify disease-specific molecular markers or to elucidate the etiopathological mechanisms. Numerous authors did however apply histochemistry to a variety of other research fields; their interests range from the microanatomy of animal and plant organisms to the cellular mechanisms of life. This is especially apparent browsing the contents of the histochemical journals where the articles on subjects other than pathology are the majority; these journals still keep a pivotal role in the field of cell and tissue biology, while being a forum for a diverse range of biologists whose scientific interests expand the research horizon of histochemistry to ever novel subjects. Thus, histochemistry can always receive inspiring stimuli toward a continuous methodological refinement.

Ultrastructural histochemistry in biomedical research: Alive and kicking

The high-resolution images provided by the electron microscopy has constituted a limitless source of information in any research field of life and materials science since the early Thirties of the last century. Browsing the scientific literature, electron microscopy was especially popular from the 1970’s to 80’s, whereas during the 90’s, with the advent of innovative molecular techniques, electron microscopy seemed to be downgraded to a subordinate role, as a merely descriptive technique. Ultra -structural histochemistry was crucial to promote the Renaissance of electron microscopy, when it became evident that a precise localization of molecules in the biological environment was necessary to fully understand their functional role. Nowadays, electron microscopy is still irreplaceable for ultrastructural morphology in basic and applied biomedical research, while the application of correlative light and electron microscopy and of refined ultrastructural histochemical techniques gives electron microscopy a central role in functional cell and tissue biology, as a really unique tool for high-resolution molecular biology in situ.

Is there still room for novelty, in histochemical papers?

Histochemistry continues to be widely applied in biomedical research, being nowadays mostly addressed to detect and locate single molecules or molecular complexes inside cells and tissues, and to relate structural organization and function at the high resolution of the more advanced microscopical techniques. In the attempt to see whether histochemical novelties may be found in the recent literature, the articles published in the European Journal of Histochemistry in the period 2014-2016 have been reviewed. In the majority of the published papers, standardized methods have been preferred by scientists to make their results reliably comparable with the data in the literature, but several papers (approximately one fourth of the published articles) described novel histochemical methods and procedures. It is worth noting that there is a growing interest for minimally-invasive in vivo techniques (magnetic resonance imaging, autofluorescence spectroscopy), which may parallel conventional histochemical analyses to acquire evidence not only on the morphological features of living organs and tissues, but also on their functional, biophysical and molecular characteristics. Thanks to this unceasing methodological refinement, histochemistry will continue to provide innovative applications in the biomedical field.