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Background: Medical students have been known to undergo tremendous stress during various stages of the MBBS course; some break down while others can cope with the same.Objective: The study aimed to assess medical students’ vulnerability to stress by identifying alterations in cardiovascular parametersunder stress and their resilience score. It was also aimed to find out the personal view of students in considering music therapy forimproving their stress coping ability or resilience.Methods: Orthostatic and mental stress were imparted in first-year medical students by quick change of posture and reading andpresenting an unknown scientific article within a fixed time, respectively. Cardiovascular parameters were measured by standardtechniques and sources of stress with stress coping strategies and resilience were done by a structured questionnaire. Music therapywas imparted after college hours with Mozart’s Symphony. All data were expressed as Mean +/- SEM and statistical significance wasassessed by using Student’s ‘T’ Test and correlation.Results: 100% of students considered academic factors as the primary source of stress, while 52-60% considered physical, emotionaland social factors. Talking to friends was rated to be the most efficient relieving strategy. The subjects were resilient to a considerableextent and their reaction time was within the normal range. Both orthostatic and mental stress caused increases in the cardiovascularparameters as compared to rest, with mental stress causing more significant changes. Subjective responses showed that 78.3% ratedmusic to be highly effective in improving coping ability.Conclusions: First-year medical students considered academic stress as the most important stress inducer in the first year of theirmedical course. Talking to friends was identified as the most effective stress relieving mode. Both orthostatic and mental stress induced significant increases in cardiovascular parameters, mental stress causing more change than the orthostatic one. The majority of students under study perceived and reported music therapy as an effective means of stress coping.

Transplantation of olfactory ensheathing cells, the glia of the primary olfactory nervous system, has been trialed for spinal cord injury repair with promising but variable outcomes in animals and humans. Olfactory ensheathing cells can be harvested either from the lamina propria beneath the neuroepithelium in the nasal cavity, or from the olfactory bulb in the brain. As these areas contain several other cell types, isolating and purifying olfactory ensheathing cells is a critical part of the process. It is largely unknown how contaminating cells such as fibroblasts, other glial cell types and supporting cells affect olfactory ensheathing cell function post-transplantation; these cells may also cause unwanted side-effects. It is also, however, possible that the presence of some of the contaminant cells can improve outcomes. Here, we reviewed the last decade of olfactory ensheathing cell transplantation studies in rodents, with a focus on olfactory ensheathing cell purity. We analyzed how purification methods and resultant cell purity differed between olfactory mucosa- and olfactory bulb-derived cell preparations. We analyzed how the studies reported on olfactory ensheathing cell purity and which criteria were used to define cells as olfactory ensheathing cells. Finally, we analyzed the correlation between cell purity and transplantation outcomes. We found that olfactory bulb-derived olfactory ensheathing cell preparations are typically purer than mucosa-derived preparations. We concluded that there is an association between high olfactory ensheathing cell purity and favourable outcomes, but the lack of olfactory ensheathing cell-specific markers severely hampers the field.

Olfactory ensheathing cells (OECs), the glial cells of the primary olfactory nervous system, support the natural regeneration of the olfactory nerve that occurs throughout life. OECs thus exhibit unique properties supporting neuronal survival and growth. Transplantation of OECs is emerging as a promising treatment for spinal cord injury; however, outcomes in both animals and humans are variable and the method needs improvement and standardization. A major reason for the discrepancy in functional outcomes is the variability in survival and integration of the transplanted cells, key factors for successful spinal cord regeneration. Here, we review the outcomes of OEC transplantation in rodent models over the last 10 years, with a focus on survival and integration of the transplanted cells. We identify the key factors influencing OEC survival: injury type, source of transplanted cells, co-transplantation with other cell types, number and concentration of cells, method of delivery, and time of transplantation after the injury. We found that two key issues are hampering optimization and standardization of OEC transplantation: lack of (1) reliable methods for identifying transplanted cells, and (2) three-dimensional systems for OEC delivery. To develop OEC transplantation as a successful and standardized therapy for spinal cord injury, we must address these issues and increase our understanding of the complex parameters influencing OEC survival.

The glial cells of the primary olfactory nervous system, olfactory ensheathing cells (OECs), are unusual in that they rarely form tumors. Only 11 cases, all of which were benign, have been reported to date. In fact, the existence of OEC tumors has been debated as the tumors closely resemble schwannomas (Schwann cell tumors), and there is no definite method for distinguishing the two tumor types. OEC transplantation is a promising therapeutic approach for nervous system injuries, and the fact that OECs are not prone to tumorigenesis is therefore vital. However, why OECs are so resistant to neoplastic transformation remains unknown. The primary olfactory nervous system is a highly dynamic region which continuously undergoes regeneration and neurogenesis throughout life. OECs have key roles in this process, providing structural and neurotrophic support as well as phagocytosing the axonal debris resulting from turnover of neurons. The olfactory mucosa and underlying tissue is also frequently exposed to infectious agents, and OECs have key innate immune roles preventing microbes from invading the central nervous system. It is possible that the unique biological functions of OECs, as well as the dynamic nature of the primary olfactory nervous system, relate to the low incidence of OEC tumors. Here, we summarize the known case reports of OEC tumors, discuss the difficulties of correctly diagnosing them, and examine the possible reasons for their rare incidence. Understanding why OECs rarely form tumors may open avenues for new strategies to combat tumorigenesis in other regions of the nervous system.

Spinal cord injury (SCI) largely leads to irreversible and permanent loss of function, most commonly as a result of trauma. Several treatment options, such as cell transplantation methods, are being researched to overcome the debilitating disabilities arising from SCI. Most pre-clinical animal trials are conducted in rodent models of SCI. While rat models of SCI have been widely used, mouse models have received less attention, even though mouse models can have significant advantages over rat models. The small size of mice equates to lower animal maintenance costs than for rats, and the availability of numerous transgenic mouse models is advantageous for many types of studies. Inducing repeatable and precise injury in the animals is the primary challenge for SCI research, which in small rodents requires high-precision surgery. The transection-type injury model has been a commonly used injury model over the last decade for transplantation-based therapeutic research, however a standardized method for inducing a complete transection-type injury in mice does not exist. We have developed a surgical protocol for inducing a complete transection type injury in C57BL/6 mice at thoracic vertebral level 10 (T10). The procedure uses a small tip drill instead of rongeurs to precisely remove the lamina, after which a thin blade with rounded cutting edge is used to induce the spinal cord transection. This method leads to reproducible transection-type injury in small rodents with minimal collateral muscle and bone damage and therefore minimizes confounding factors, specifically where behavioral functional outcomes are analyzed.

Cell transplantation constitutes an important avenue for development of new treatments for spinal cord injury (SCI). These therapies are aimed at supporting neural repair and/or replacing lost cells at the injury site. To date, various cell types have been trialed, with most studies focusing on different types of stem cells or glial cells. Here, we review commonly used cell transplantation approaches for spinal cord injury (SCI) repair, with focus on transplantation of olfactory ensheathing cells (OECs), the glial cells of the primary olfactory nervous system. OECs are promising candidates for promotion of neural repair given that they support continuous regeneration of the olfactory nerve that occurs throughout life. Further, OECs can be accessed from the nasal mucosa (olfactory neuroepithelium) at the roof of the nasal cavity and can be autologously transplanted. OEC transplantation has been trialed in many animal models of SCI, as well as in human clinical trials. While several studies have been promising, outcomes are variable and the method needs improvement to enhance aspects such as cell survival, integration, and migration. As a case study, we include the approaches used by our team (the Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia) to address the current problems with OEC transplantation and discuss how the therapeutic potential of OEC transplantation can be improved. Our approach includes discovery research to improve our knowledge of OEC biology, identifying natural and synthetic compounds to stimulate the neural repair properties of OECs, and designing three-dimensional cell constructs to create stable and transplantable cell structures.

Olfactory ensheathing cells (OECs) are crucial players in the continuous regeneration of the olfactory nervous system that occurs through out life and are thought to have unique growth-promoting properties. For this reason, OEC transplantation has been thoroughly explored for the potential to promote neural repair after both central and peripheral nervous system injuries. Numerous studies have shown that OEC transplantation is safe and can promote recovery after spinal cord injury (SCI), both in animal models and in human clinical trials. To date, a variety of injury types and time-points after injury, as well as different delivery methods, have been tested. Outcomes have been encouraging (in rodent models including, for example, restoration of locomotion, breathing and climbing ability along with induction of axonal sprouting and some axonal regeneration) but highly variable (Barnett and Riddell, 2007; Gomez et al., 2018). In their natural environment of the primary olfactory nervous system (the olfactory nerve and outer layer of the olfactory bulb), OECs provide structural support for olfactory axons and secrete a range of growth and guidance factors as well as basement membrane components. OECs also phagocytose debris arising from degenerating axons (Ekberg and St John, 2014). In the injured spinal cord, OECs (in addition to these functions) also exhibit a unique capacity for migration into scar tissue and for integration with astrocytes (Barnett and Riddell, 2007; Gomez et al., 2018). For these neural repair effects to occur, it is essential that the transplanted cells survive over time. The key factor for success is thus that the OECs must not only arrive at the right place within the injury site, but must also over time integrate and interact with the injured tissue.