Reproductive endocrine patterns were characterized in female ocelots (Leopardus pardalis; n = 3), tigrinas (Leopardus tigrinus; n = 2), and margays (Leopardus wiedii; n = 2) housed in captivity in southern Brazil. Females were maintained as singletons and exposed to natural fluctuations in photoperiod. Cyclic changes in ovarian steroids were monitored by analyzing estrogen and progestogen metabolites in fecal samples collected five times weekly for 14 to 18 months. Based on intervals between fecal estrogen peaks, mean (+/- SEM) duration of the estrous cycle was 18.4 +/- 1.6 days for the ocelots (range, 7-31 days; n = 75 cycles), 16.7 +/- 1.3 days for the tigrinas (range, 11-27 days; n = 23 cycles), and 17.6 +/- 1.5 days for the margays (range, 11-25 days; n = 32 cycles). Fecal progestogen analyses combined with two laparoscopic observations of the ovaries confirmed that ocelots and tigrinas did not ovulate spontaneously. In contrast, non-mating-induced luteal phases of 40.1 +/- 6.3 days in duration (range, 30-60 days) were observed frequently in both margays. There was no evidence of gonadal seasonality in margays in either follicular or luteal activity. In ocelots, cyclic changes in estrogen excretion were observed during each month of the year; however, only one female cycled continuously. In the other two ocelots, periods of acyclicity of several months' duration were observed. It was not possible to conclude whether tigrinas were aseasonal because estrous cyclicity was observed in only one of two individuals. In the female that cycled, a 3-month period of acyclicity was observed in the late fall/early winter. These data demonstrate similarities among three felid species of the genus Leopardus, including evidence they are polyestrous but experience unexplained periods of ovarian inactivity. Only the margays differed by exhibiting occasional spontaneous, non-mating-induced ovulations. Historically, these species have not bred well in captivity. However, it is hoped that understanding the biological similarities and differences among them could lead to improved management strategies that may one day result in increased reproductive success. Zoo Biol 20:103-116, 2001. Copyright 2001 Wiley-Liss, Inc.

Society has been increasingly exposed to low-frequency electromagnetic fields (EMF), mainly from electricity distribution networks and electro-electronic devices. Aiming to clarify the extension of possible interactions between EMF and testicular development, this study evaluated the effects of exposure to 60 Hz and 1 mT EMF in the maturation of testicular components. Wistar rats were exposed to EMF three times per day for 30 min, between the 13th day of gestation and the 21st postnatal day. Results showed a decrease in the following parameters: tubular diameter and seminiferous tubules area; seminiferous epithelium height; total volume of seminiferous tubule; tubular lumen; seminiferous epithelium; and Leydig cells. On the other hand, an increase was observed in connective tissue cells and blood vessels volume. Plasma testosterone, Sertoli cells population, tubular length and gonadosomatic index did not change when exposed to EMF. Histomorphometric analysis showed that exposure to EMF can promote a delay in testicular development.

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Reproductive evaluations were conducted on 185 male cats representing eight endemic Latin American species that were maintained in 44 zoos and private facilities in 12 Latin American countries. Reproductive assessments (testicular measures, ejaculate quality, and blood testosterone/cortisol concentration) were used to establish normative values for large-and small-sized cats in Latin American collections. Data also were analyzed using multiple regression to study the impact of proven breeder status, diet, and various animal housing combinations. Most felids (495%) in the survey were of wild-born origin, and o20% had produced offspring in captivity. Larger felids had bigger testes and produced more semen, but tended to produce low-sperm-density ejaculates. The ejaculates of small felids were more sperm-concentrated, but contained fewer total spermatozoa. Sperm motility was unrelated to species size, and certain species (puma, margay, tigrina, and jaguarundi) consistently produced few (o40%) normal sperm forms. Across species, 450% of males had low sperm counts (o1 million total sperm per ejaculate). Among large cats (jaguars and pumas), proven breeders had larger (Po0.05) testes, greater semen volume, and more normal sperm than nonbreeders. Males on adequate diets had higher (Po0.05) circulating cortisol. Among small-sized felids, proven breeders had higher (Po0.05) testosterone, and males housed alone or paired with a conspecific female had more (Po0.05) total sperm per ejaculate and greater (Po0.05) seminal and testicular volumes. Fifty-nine ejaculates (potentially representing B100 artificial insemination (AI) or 26,000 in vitro fertilization (IVF) procedures) were cryopreserved for a felid genome resource bank. In conclusion, breeding success and reproductive traits for many endemic felids in Latin American zoos appear to be suboptimal, and likely would benefit from improvements in diet and exhibitry. Technology transfer and continued training of zoo staff and scientists in Latin American countries are essential if these zoos are to achieve their tremendous conservation potential for felids and other threatened endemic species.

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Sleep disorders increase pain sensitivity and the risk of developing painful conditions; however, the underlying mechanisms are poorly understood. It has been suggested that nucleus accumbens (NAc) influences sleep-wake cycle by means of a balance between adenosine activity at A2A receptors and dopamine activity at D2 receptors. Because the NAc also plays an important role in pain modulation, we hypothesized that the NAc and its A2A and D2 receptors mediate the pronociceptive effect of rapid eye movement (REM) sleep deprivation (SD). We found that 24 hours of REM-SD induced an intense pronociceptive effect in Wistar rats, which decreases progressively over a sleep rebound period. Although the level of fecal glucocorticoid metabolites increased with SD within group, it did not differ between sleep-deprived group and control group, indicating a stress response with similar magnitude between groups. The pronociceptive effect of REM-SD was prevented by excitotoxic lesion (N-Methyl-D-aspartate, 5.5 μg) of NAc and reverted by its acute blockade (Qx-314, 2%). The administration of an A2A receptor antagonist (SCH-58261, 7 ng) or a D2 receptor agonist (piribedil, 6 μg) into the NAc increased home cage activity and blocked the pronociceptive effect of REM-SD. Complementarily, an A2A receptor agonist (CGS-21680, 24 ng) impaired the reversal of the pronociceptive effect and decreased home cage activity, as it did a D2 receptor antagonist (raclopride, 5 μg). Rapid eye movement SD did not affect the expression of c-Fos protein in NAc. These data suggest that SD increases pain by increasing NAc adenosinergic A2A activity and by decreasing NAc dopaminergic D2 activity.

The population exposure to electromagnetic fields (EMF) has been growing in recent decades. The generation, distribution and use of electric energy can generate low-frequency electromagnetic fields. The present study investigates the effects of EMF (60 Hz and 1 mT) on spermatogenesis of rats during different periods of maturation. Wistar rats were exposed to EMF from day 13 of gestation to postnatal day 21 or 90 in three daily applications of 30 min. Plasma testosterone concentration was not changed by EMF exposure; however, histopathological and histomorphometrical analyses of the testes showed testicular degeneration in a subset of animals exposed to EMF. The magnitude of the degenerative process varied between those individuals affected, indicating different individual sensitivity to EMF. The main alterations observed through transmission electron microscopy were highly electron-dense mitochondria with loss of their organization and cristae. Exposure to 60 Hz and 1 mT EMF can disturb spermatogenesis and may produce subfertility or infertility.

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