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The beetle suborder Adephaga is traditionally divided into two sections on the basis of habitat, terrestrial Geadephaga and aquatic Hydradephaga. Monophyly of both groups is uncertain, and the relationship of the two groups has implications for inferring habitat transitions within Adephaga. Here we examine phylogenetic relationships of these groups using evidence provided by DNA sequences from all four suborders of beetles, including 60 species of Adephaga, four Archostemata, three Myxophaga, and ten Polyphaga. We studied 18S ribosomal DNA and 28S ribosomal DNA, aligned with consideration of secondary structure, as well as the nuclear protein-coding gene wingless. Independent and combined Bayesian, likelihood, and parsimony analyses of all three genes supported placement of Trachypachidae in a monophyletic Geadephaga, although for analyses of 28S rDNA and some parsimony analyses only if Coleoptera is constrained to be monophyletic. Most analyses showed limited support for the monophyly of Hydradephaga. Outside of Adephaga, there is support from the ribosomal genes for a sister group relationship between Adephaga and Polyphaga. Within the small number of sampled Polyphaga, analyses of 18S rDNA, wingless, and the combined matrix supports monophyly of Polyphaga exclusive of Scirtoidea. Unconstrained analyses of the evolution of habitat suggest that Adephaga was ancestrally aquatic with one transition to terrestrial. However, in analyses constrained to disallow changes from aquatic to terrestrial habitat, the phylogenies imply two origins of aquatic habit within Adephaga.

OBJECTIVE—Chronic seizures in women can have adverse effects on reproductive function, such as polycystic ovarian syndrome (PCOS), but it has been difficult to dissociate the effects of epilepsy per se from the role of antiepileptic drugs (AEDs). To distinguish the effects of chronic seizures from AEDs, we used the laboratory rat, where an epileptic condition can be induced without concomitant AED treatment. METHODS—Adult female rats were administered the chemoconvulsant pilocarpine to initiate status epilepticus (SE), which was decreased in severity by the anticonvulsant diazepam. These rats developed spontaneous seizures in the ensuing weeks, and are therefore termed “epileptic.” Controls were saline-treated rats, or animals that were injected with pilocarpine but did not develop SE. Ovarian cyclicity and weight gain were evaluated for 2-3 months. Serum hormone levels were assayed from trunk blood, collected at the time of death. Paraformaldehyde-fixed ovaries were evaluated quantitatively. RESULTS—Rats that had pilocarpine-induced seizures had an increased incidence of acyclicity by the end of the study, even if SE did not occur. Ovarian cysts and weight gain were significantly greater in epileptic rats than controls, whether rats maintained cyclicity or not. Serum testosterone was elevated in epileptic rats, but estradiol, progesterone and prolactin were not. INTERPRETATIONS—The results suggest that an epileptic condition in the rat leads to increased body weight, cystic ovaries and elevated testosterone levels. Although caution is required when comparing female rats to women, the data suggest that epilepsy per se may be sufficient to induce abnormalities in the control of the ovary.

In adult female rats, robust hippocampal changes occur when estradiol rises on the morning of proestrus. Whether estradiol mediates these changes, however, remains unknown. To address this issue, we used sequential injections of estradiol to simulate two key components of the preovulatory surge: the rapid rise in estradiol on proestrous morning, and the slower rise during the preceding day, diestrus 2. Animals were examined mid-morning of simulated proestrus, and compared to vehicle-treated or intact rats. In both simulated and intact rats, CA1-evoked responses were potentiated in hippocampal slices, and presynaptic mechanisms appeared to contribute. In CA3, multiple population spikes were evoked in response to mossy fiber stimuli, and expression of brain-derived neurotrophic factor was increased. Simulation of proestrous morning also improved performance on object and place recognition tests, in comparison to vehicle treatment. Surprisingly, effects on CA1-evoked responses showed a dependence on estradiol during simulated diestrus 2, as well as a dependence on proestrous morning. Increasing estradiol above the physiological range on proestrous morning paradoxically decreased evoked responses in CA1. However, CA3 pyramidal cell activity increased further, and became synchronized. Together, the results confirm that physiological estradiol levels are sufficient to profoundly affect hippocampal function. In addition: (i) changes on proestrous morning appear to depend on slow increases in estradiol during the preceding day; (ii) effects are extremely sensitive to the peak serum level on proestrous morning; and (iii) there are striking subfield differences within the hippocampus.

Reproductive cyclicity has a significant influence on the regulation of circadian rhythms in rodents. Studies have suggested that there are changes in body temperature rhythms between the follicular and luteal phases in human females. This study examined the effects of menstrual cyclicity on physiological and behavioral circadian rhythms in female rhesus monkeys (Macaca mulatta), an acknowledged biomedical model. Seven unrestrained subjects were implanted with a biotelemetry transmitter to measure body temperature and heart rate and an accelerometer was used to measure physical activity. Water was available ad libitum and drinking was measured via an electronic circuit attached to a water lixit. A video-based task system, the Psychomotor Test System, provided environmental enrichment and delivered a pelletized diet. Mean, phase, and amplitude of each rhythm were calculated. Estrogen and progesterone conjugates were assayed and quantified from daily urine samples to identify follicular and luteal phases of the menstrual cycle. Average circadian variables were then compared between these phases. Heart rate was significantly (P< or =0.05) delayed in the luteal phase. Albeit non-significant, analysis showed a trend toward decreased circadian amplitude of body temperature in the luteal phase.

A centrifuge in space provides the only method to create environments between 0-1G to understand the interactions between biological systems and gravity. Current designs for an on-board centrifuge are short radius. However, the rotation rate to achieve +G increases as radius decreases, also enhancing irregularities in +G fields produced by centrifuge geometry and operation. Both centrifuge radius and rotation rate play a role in the adaptive response to altered G. This study examined the adaptation profiles of adult female mice to 8 weeks of chronic centrifugation. A rotation rate that would result in a 1.0 G environment in space was used to produce the maximum +G environment for this study. The +G field was either presented immediately upon centrifugation onset (acute) or in 4 equal increases (stepped) at two-week intervals. Data were collected from: experimental (short 0.67 m diameter), force control (large 4.5 m diameter), cage control (the experimental cage) and vivarium control groups. Each group had...

The effects of division of labour on response behaviour to food in the red imported fire ant, Solenopsis invicta Buren, were examined to determine if caste members differ in amount of food taken, in rate of food transfer, or in internal distribution of food; and to see if food availability, time, or temporal subcaste pairing affect feeding behaviour. To measure differences in behaviour we fed radioiodinated albumin mixed with egg yolk to colonies containing larvae, queens, and (a) foragers and nurses, or (b) foragers and reserves, or (c) nurses and reserves. Samples were taken over a 72-h period and radioactivity in the head, thorax and abdomen of each worker was determined. There were significant differences between nurses, foragers and reserves in quantity of food consumed, rate of transfer, and internal distribution of radioactivity. These differences were related to their respective roles of foraging, food storage and transfer, and brood tending. The quantity of food taken per subcaste was dependent on the total amount of food in the colony, with transfer rates differing between subcastes as the quantity of food in the colony increased. The rate at which protein was transferred between subcastes was slower in the reserves than that in either foragers or nurses. Therefore, reserves may serve as a temporary store of protein for the colony.

Trophallactic behaviour of temporal subcastes in Solenopsis invicta Buren colonies was studied in two separate experiments. First, radiolabeled honey was presented to small colonies containing larvae, queens and marked workers; radioactivity in the head, thorax and abdomen of each ant was measured after 0.25, 1, 6, 12, 24, 48 and 72 h. The quantity of honey per subcaste was dependent on the total amount of honey collected. As more honey entered the colony, the quantity in foragers, queens and reserves increased more rapidly than that in nurses or larvae. The internal distribution of radioactivity in the head, thorax or abdomen indicated that differences between subcaste members in either the rate of food exchange or digestion existed. In a second experiment behavioural observations were made on marked workers in colonies before and after the presentation of honey. Reserves spent significantly more time engaged in trophallaxis than either foragers or nurses, both as active donors and active receivers. Based on number of encounters, nurses were more likely to receive honey while reserves and foragers were more likely to donate honey. The duration of encounters involving nurses tended to be shorter than those involving reserves or foragers.