Meal pattern of male rats maintained on histidine-, leucine-, or tyrosine-supplemented diet

Objective: Food intake is known to be affected by macronutrient composition of the diet, and protein manipulation has been reported to alter food intake, but the effect of individual amino acids on eating behavior has not been fully studied. This study investigated the effect of diet supplementation with three individual amino acids on meal pattern in male rats. Research Methods and Procedures: Thirty‐two Sprague‐Dawley rats were randomly divided into four equal groups and fed control diet or histidine (5%)‐, leucine (5%)‐, or tyrosine (5%)‐supplemented diet for 2 weeks and were monitored for their meal pattern. Results: Total food intake and feeding rate of the different groups were not affected, although other components of meal pattern were altered. Histidine supplementation reduced diurnal meal size by 42% (p < 0.05), whereas that of leucine increased nocturnal meal size by ～35% (p < 0.05). Tyrosine supplementation increased food intake of the nocturnal period and decreased that of the diurnal period. Both histidine and tyrosine supplementation elevated fasting plasma insulin levels and suppressed fasting glucose significantly. Discussion: Individual amino acids were found to alter meal pattern differently. Further investigations are required to dissect the involvement of central and peripheral factors in these alterations.     

Association of eating frequency with body fatness in pre- and postmenopausal women

Objective: To examine associations between eating frequency (EF) and body fatness in pre‐ and postmenopausal women, after excluding potential low‐energy reporters. Research Methods and Procedures: In this cross‐sectional study of 220 free‐living women, 64 pre‐ and 50 postmenopausal non‐low‐energy‐reporting women were further analyzed (age, 24 to 74 years; BMI, 18.5 to 38.6 kg/m²). Anthropometric and body composition measurements (DXA) were performed in all study participants. EF, energy, and macronutrient intake were assessed by 3‐day food record. Physical activity level and energy expenditure were assessed by self‐reported questionnaire. Results: No association between EF and adiposity indices was detected in premenopausal women. In contrast, EF was positively correlated with percentage body fat in postmenopausal women (r = 0.30, p = 0.03). EF was positively correlated with total energy intake in both groups and with total energy expenditure in premenopausal women only (r = 0.34, p = 0.02). Multivariate analysis revealed that, in postmenopausal women, EF was a significant predictor of body fatness (standardized β = 0.41, p = 0.01). Discussion: Frequent eating was not found to be related to adiposity in premenopausal women, but it was associated with increased body fat in postmenopausal women. Possible explanations could be that the frequent eating is not associated with a physically active lifestyle in postmenopausal women or that frequent eating predisposes women after menopause to a higher energy intake by increasing food stimuli and rendering it more difficult for them to control energy balance.     

Semi-lunar spawning cycle and mating tactics in the marine goby <Emphasis Type="Italic">Asterropteryx semipunctata</Emphasis>

The reproductive behaviors of the marine goby Asterropteryx semipunctata were studied at Sakurajima, Kagoshima, Japan. Spawning occurred from late June to early October with a peak at 3–4 days after the full and new moon. This semi-lunar cycle might be advantageous to reducing nest-egg mortality but may not to larvae dispersion. Large males maintained spawning nests, and females spawned a whole clutch at a nest but with multiple males during a season. Females were less likely to be choosy due probably to a predation risk and/or nesting male shortage. Smaller males adopted sneaking tactics, and some of them became nesting males.     

Volatiles induced by the larvae of the Asian corn borer (Ostrinia furnacalis) in maize plants affect behavior of conspecific larvae and female adults

Abstract  Effects of maize ( Zea mays L.) volatiles induced by larvae of the Asian corn borer, Ostrinia furnacalis (Guenée), on the orientation behaviors of Asian corn borer larvae and oviposition of the females were investigated. Nineteen volatile chemicals, with terpenes being the major components, were identified from maize plants attacked by third instar Asian corn borer larvae. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses revealed some electroantennographic differences between female and male Asian corn borer antennae in response to larvae-induced maize volatiles; female responded to ( E )-2-hexenal, nonanal, ( Z )-3-hexen-1-ol and three unknown compounds while the male only responded to ( E )-2-hexenal, nonanal and one unknown compound. In laboratory orientation bioassays, Asian corn borer neonate larvae were attracted to extracts collected from Asian corn borer-damaged plants as well as to synthetic farnesene, but were repelled by ( Z )-3-hexen-1-ol. In laboratory oviposition bioassays, gravid females laid fewer eggs on plants damaged by larvae than on mechanically damaged plants or undamaged plants. Adult Asian corn borer females deposited fewer eggs on wax paper treated with ( E )-2-hexenal or ( Z )-3-hexen-1-ol than on wax paper treated with hexane (control). The results suggest that Asian corn borer can affect the behaviors of conspecific larvae and adults by changing host plant volatiles.     

CCK-8 modulation of mesolimbic dopamine: Antagonism of amphetamine-stimulated behaviors

Rats (N=15) were implanted with cannulae above the dopaminergic A10 ventral tegmental area (VTA). Two weeks later, four measures of open field behavior were quantified for 10 minutes commencing 30 minutes after parenteral d-amphetamine (1.5 mg/kg) and directly after bilateral infusion of 1.5 μl of: (a) artificial CSF only (VEH), (b) 1.25 μg desulfated CCK (DS-CCK), or (c) 1.25 μg sulfated CCK (CCK). Additional rats with bilateral cannulae directed toward the A10 terminal zones of nucleus accumbens were similarly tested with either VEH (N=2) or sulfated CCK (N=2). With VTA infusions, both the number of occurrences and duration of rearing were significantly reduced in CCK rats, while neither the number of square crossings nor duration of forward locomotion were significantly modified from controls. With nuclei accumbens septi (NAS) infusions, CCK-8 reduced rearing behavior more than ambulatory behavior in this preliminary testing. With either VTA or NAS infusions, no significant differences from controls were found upon two derived measures of motoric performance, namely, “velocity” (number of squares crossed per second in locomotion) and “vertical stability” (seconds per rear). These results suggest a modulation of dopaminergically-mediated behavior by (sulfated) CCK-8 at the cell body region and terminal fields of the mesolimbic (A10) dopamine system.     

Effects of visitors and cage changes on the behaviors of mangabeys

Three groups of golden-bellied mangabeys were studied to determine the effects of visitors and cage changes on their aggressive displays, grooming and sexual behavior, and play. Assessments of changes in behavior were made by comparing categorized observer comments. Animals moved to cages having more visitors increased their aggressive displays toward people, decreased their aggressive displays toward other species in neighboring cages, and increased their withingroup aggression. On the other hand, grooming, sexual behavior, and play increased after cage changes regardless of numbers of visitors. The view that it is the pattern of behavior changes in enrichment that is important in assessment of attempted enrichment was supported. Aggressive and affiliative behaviors are affected quite differently by different environmental stimuli in the zoo.     

Comparison of affiliative behaviors between old and recently established pairs of golden lion tamarin,Leontopithecus rosalia

To evaluate the changes in the relationship between male and femaleLeontopithecus rosalia over time, I compared the interactions in four well established pairs at the National Zoological Park, Washington, D.C., to those in four newly established pairs at the Conservation and Research Center of the National Zoological Park, Front Royal, Virginia, U.S.A. I recorded the frequency of approaches, withdrawals, food offerings, food takings, and resisting food transfers. Male and female adults were the focal animals and the observations totaled 206.5 hr. Males of newly established pairs interacted more with females than males of old established pairs. While males generally began and maintained the interactions significantly more than females, females of recently formed pairs were initiators of affiliative behaviors significantly more than females of old pairs. These results demonstrate a qualitative difference in the relationship between males and females when old and new pairs are compared.     

Orientation of male gypsy moths,Lymantria Dispar (L.), to pheromone sources: The role of olfactory and visual cues

The role of olfaction and vision in the close-ranging flying and walking orientation of male gypsy moths, Lymantria dispar(L.), to females was studied in the forest and in the laboratory. In the forest, feral males found an isolated pheromone source as readily as one supplemented with female visual cues; dead, acetonerinsed females deployed without pheromone received virtually no visitations. In flight tunnel choice experiments using cylinders as surrogate trees and pheromone in different spatial configurations, visual attributes of the female did not influence either the males' choice of landing site or the efficiency with which they located the female. Rather, the presence of pheromone on the cylinder was necessary to elicit orientation as well as landing and walking on the cylinder. When a female visual model was placed in various positions around a pheromone source, walking males oriented primarily to the chemical stimulus. There were, however, indications that males would alter their walking paths in response to female visual cues over short distances (<5 cm), but only if they continued to receive pheromone stimulation. When visual and chemical cues were abruptly uncoupled by altering the trajectory of the pheromone plume, most males responded to the loss of the odor cue rather than to visual cues from the female. Temporal pheromone stimulation patterns affected male walking orientation. When stimulated by pheromone, males oriented toward the source; loss of the odor cue prompted an arearestricted local search characterized by primarily vertical and oblique movements with frequent reversals in direction. Presumably these maneuvers enhance the likelihood of recontacting the plume or serendipitously encountering the female. The apparent lack of visual response to the female is discussed in light of morphological and behavioral evidence suggesting that gypsy moths were formerly nocturnal.     

Host activity and the risk of nest parasitism by brown-headed cowbirds

Proportions of nests parasitized by brown-headed cowbirds (Molothrus ater) vary greatly among host species, but factors underlyingthis variation remain poorly understood. Cowbirds are believedto find nests by watching host behavior. We tested the hypothesisthat the activity of hosts during nest building correlateswith the probability of parasitism among and within four sympatrichosts: dusky flycatchers (Empidonax oberholseri), warblingvireos (Vireo gilvus), yellow warblers (Dendroica petechia),and American redstarts (Setophaga ruticilla). Daily probabilityof parasitism varied substantially among these species, from3% for dusky flycatchers to more than four times that for warblingvireos. The four species did not differ in the proportion ofcowbirds fledged from their nests. Differences in nest placementdid not explain differences in probability of parasitism amongor within species. Parasitism frequencies increased among speciesthat made longer nest-building visits, had a greater propensityto perch during nest approach, spent more time near their nests,and had males that vocalized more often near nests. Within species, females that visited their nests less often, spent more timeon the nest per visit, and males that sang more and were activein a smaller area around their nests were more likely to beparasitized by cowbirds. These data support the hypothesisthat cowbirds use the activity of hosts during nest buildingto locate nests.     

神农架川金丝猴投食群的攻击行为及等级序列

为探讨人工补食条件下川金丝猴的攻击行为在维持社会等级中的作用,2007 年1 ～ 6 月,采用行为取样法
和全事件记录法对神农架自然保护区投食群的攻击行为及等级序列进行研究。我们共记录到8 种攻击行为,按
频次多少依次为:咕叫、抓打、追赶、瞪眼、瞪咕、驱赶、抢食、打架。攻击行为的发起者在性别间和年龄间
均存在显著差异,雄性多于雌性,年龄间按次数多少依次为:成年猴、亚成年猴、青年猴、少年猴;承受者在
性别间和年龄间差异均不显著。社会单元内与单元间攻击行为差异显著,前者多于后者。一雄多雌单元间的等
级高低依次为:长毛单元、白头单元、红头单元。基于单元内攻击行为较多,建议适当扩大投食场,给每只个
体分别投食,以减少因争食发生的攻击行为。