This study was carried out to determine if exposure to hot environmental temperatures had a direct, detrimental effect on sperm quality. For this the effect of whole-body heat exposure on epididymal spermatozoa of laboratory mice was investigated. C57BL/6 mice (n = 7) were housed in a microclimate chamber at 37ºC-38ºC for 8 h per day for three consecutive days, while control mice (n = 7) were kept at 23ºC-24ºC. Cauda epididymal spermatozoa were obtained 16 h after the last heat treatment. The results showed that sperm numbers were similar in the two groups (P = 0.23), but after heat treatment, a significant reduction in the percentage of motile sperm was present (P < 0.0001). Membrane changes of the spermatozoa were investigated by staining with phycoerythrin (PE)-conjugated Annexin V, which detects exteriorization of phosphotidylserine from the inner to the outer leaflet of the sperm plasma membrane, and 7-aminoactinomycin D (7-AAD), which binds to the sperm nucleus when the plasma membrane is damaged. The percentage of spermatozoa showing positive staining with Annexin V-PE or 7-AAD or both, was significantly higher (P < 0.05) in heat-exposed mice compared with controls. These results show that whole-body heat exposure to 37ºC-38ºC induces membrane changes in the epididymal spermatozoa of mice, which may lead to apoptosis.

Allied health professionals require an understanding of anatomy for purposes such as planning radiotherapy, or treating muscle imbalance. In practice, they will rarely see the structure they are treating, but seeing it during their education is invaluable. To reveal deep structures in the human body, neighbouring structures are unavoidably removed as a donated human body is dissected. Academic and clinical staff approached the challenge for students' understanding of the male reproductive and urinary system, which is indeed disrupted by dissection. An existing radiotherapy planning instrument Virtual Environment for Radiotherapy Training was used to create videos of real patients' internal structures. Structures difficult to see in dissection, models and images were transformed from magnetic resonance and computerised tomography scans into videos that appeared three-dimensional, for use by students learning anatomy. Qualitative evaluation of these anatomy videos suggested that they can be accessed at students' convenience and can be customised with captions, pauses or quizzes. Quantitative evaluation suggested that offering assessment-related incentives may not result in all students choosing to access the videos, but that those who did performed better on both labelling and short answer explanations of related content on immediate and short-term testing.

This study investigated the effects of high temperatures on male germ cell development and epididymal sperm motility of laboratory mice. In Experiment 1, adult males (n=16) were exposed to whole-body heat of 37-38°C for 8h day(-1) for 3 consecutive days, whereas controls (n=4) were left at 23-24°C. In Experiment 2, adult mice (n=6) were exposed to 37-38°C for a single 8-h period with controls (n=6) left at 23-24°C. Experiment 2 was conducted as a continuation of previous study that showed changes in spermatozoa 16h after exposure to heat of 37-38°C for 8h day(-1) for 3 consecutive days. In the present study, in Experiment 1, high temperature reduced testes weights 16h and 14 days after exposure, whereas by Day 21 testes weights were similar to those in the control group (P=0.18). At 16h, 7 and 14 days after exposure, an increase in germ cell apoptosis was noticeable in early and late stages (I-VI and XI-XII) of the cycle of the seminiferous epithelium. However, apoptosis in intermediate stages (VII-X) was evident 16h after heat exposure (P<0.05), without any change at other time periods. By 21 days, there were no significant differences between heat-treated groups and controls. Considerably more caspase-3-positive germ cells occurred in heat-treated mice 16h after heat exposure compared with the control group (P<0.0001), whereas 8h after heat in Experiment 2, sperm motility was reduced with a higher percentage of spermatozoa showing membrane damage. In conclusion, the present study shows that whole-body heat of 37-38°C induces stage-specific germ cell apoptosis and membrane changes in spermatozoa; this may result in reduced fertility at particular times of exposure after heating.

In most mammalian species, the temperature of scrotal testes is several degrees lower than that of core body temperature due to the presence of a counter-current heat exchange between the coiled testicular artery and the pampiniform plexus of veins. Here we ask: have hopping mice developed a highly efficient cooling mechanism within their scrotal sac and/or germ cell resistance to high environmental temperatures? To investigate this, adult male sexually mature Notomys alexis were used to determine: (1) the temperature of the testes; (2) the extent of coiling of the testicular artery; (3) the effect of artificially induced cryptorchidism on spermatogenesis up to three weeks after surgery; and (4) the effect of whole body heat exposure of 37−38°C for 8 h per day for three consecutive days on germ cell apoptosis. The results showed that in hopping mice the testicular artery, unlike that in most other mammalian species, is not coiled although the temperature in the scrotum was found to be ~2°C lower than that of the abdomen. In cryptorchid males, 21 days after surgery, testes weights were reduced in three of five individuals but there was no statistically significant decrease after 16 h exposure to whole body heat (P = 0.07). Nevertheless, some impairment of spermatogenesis was evident in both the cryptorchid testes and in the testes after whole body heating. These results show that in hopping mice developing male germ cells are susceptible to degeneration when testes are exposed to high environmental temperatures. Thus adaptations of Notomys alexis to the arid zone have not involved any special adaptations for male germ cell survival in a hot environment. Behavioural adaptations may play a pivotal role in maintaining maximal male fertility in such extreme environmental conditions.

Introduction: The aim of the present study was to determine the immediate effects of whole body heating on sperm numbers, motility and apoptosis. Material and Methods: C57BL/6 mice (n=7) were exposed to 37-38oC (8 hours/day), for three consecutive days while control mice (n=7) were kept at 23-24oC. Caudal epididymal spermatozoa were collected from control and heat treated mice 16 hours after the last heat treatment to determine the sperm number and motility using a Neubauer haemocytometer and sperm apoptotic changes by dual colorflow cytometry using Annexin V/PE (Annexin V conjugated with phycoerythrin) and 7AAD (7-amino-actinomycin D) stains. Results: There were no significant differences (p>0.05) in sperm numbers between heat treated and control mice, however heating did result in a significant reduction in sperm motility (p<0.05). Apoptosis staining identified four different subpopulations of spermatozoa: (a) live spermatozoa (Annexin V-/7AAD-), (b) early apoptotic spermatozoa with exteriorized phosphotidylserine (PS) receptor and intact plasmalemma (Annexin V+/7AAD-), (c) late apoptotic spermatozoa with PS receptor translocation and leaky plasmalemma (Annexin V+/7AAD+) and (d) dead spermatozoa with damaged plasmalemma with no detectable PS receptor (Annexin V-/7AAD+). Heating resulted in significant reduction in the percentage of live spermatozoa (p<0.05), an increase in early apoptotic (p<0.05), late apoptotic (p<0.05), and dead spermatozoa (p<0.05). Conclusion: This study shows that mice exposed to whole body heat exposure of 37-38oC for 8 hours per day for three consecutive days exhibited early and late apoptotic changes to epididymal spermatozoa. These findings suggest possible adverse effects of exposure to high temperature on the viability of human spermatozoa in the epididymides. In addition, these findings reinforce the importance of temperature during sperm preparation procedures in infertility clinics, and research laboratories.

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