Interommatidial sensilla of the praying mantis: Their central neural projections and role in head-cleaning behavior

The compound eye of the praying mantis is covered with approximately 600 bristles and campaniform sensilla. Their afferents project to the brain, and to the suboesophageal and prothoracic ganglia. Cutting the eye branch of the dorsal tegumentary nerve (DTN), the peripheral nerve innervating the corneal sensilla, makes it impossible to initiate head grooming by tactile stimulation of the eye. This stimulus is a strong releaser of grooming behavior in normal animals. Head grooming can be initiated, after cutting the eye branch of the DTN, by stimulation of the frons (the operation leaves the sensory innervation of this part of the cuticle intact). Frame-by-frame analysis of films of head grooming after cutting the nerve reveals a reduction of the speed at which the forelimb is brushed across the surface of the head and eye. The significance of this finding is discussed in terms of a putative feedback loop from the corneal sensilla to the motor neurons controlling the grooming movements.     

Description of the behavior of praying mantis with particular reference to grooming

Eighteen behavior patterns, encompassing most of the observable behavior of individually housed praying mantids, Sphodromantis lineola, were recorded using a point sampling technique. The data were sorted into four major behavioral categories: (1) food acquisition, (2) grooming, (3) inactivity, and (4) locomotion and miscellaneous. The mantids spent most of the time in an inactive state, which is consistent with their way of life as ambushing predators. Most of the animals' active time was spent in food acquisition (60%). Grooming behaviors comprised 16.7% of the active time; foreleg grooming represented 82% of grooming, while head grooming represented 14.3%. Analysis of the behavioral states in close temporal proximity to head grooming indicated that head grooming often follows foreleg grooming, occuring in bouts of about 1/2 to 1 min duration. Foreleg grooming is also closely associated with eating and seems to represent a pivotal behavior pattern between food acquisition and grooming, possibly sharing causal factors with both.     

Dopamine D1 activation shortens the duration of phases in stereotyped grooming sequences

Rats frequently emit grooming actions in a highly stereotyped, syntactic chain in which three distinct phases of facially directed forearm movements are sequentially emitted in a rule-governed pattern and followed by body-directed licking. The present study evaluated the effects of the full dopamine D1 agonist, SKF 81297, and the partial dopamine D1 agonist, SKF 38393, on the duration of individual phases of stereotyped grooming chains. We found that systemic administration of SKF 81297 significantly shortened grooming chain duration. An examination of the fine temporal structure of syntactic grooming chain actions showed that duration changes were correlated with decreased numbers of actions in phases I and IV of the chain. Phases II and III were not changed in duration, although there were some structural distortions introduced. The partial D1 agonist, SKF 38393, had no effect on duration or number of component actions in the grooming chain. Based on these results, we hypothesize that the timing of syntactic grooming phase transitions may involve a D1-mediated internal clock process that is altered by full D1 agonist activation. By this model, SKF 81297 increases the speed of the clock used for the temporal control of grooming actions, and thus shortens phase durations.     

Circadian Rhythmicity of Grooming Behavior During Pregnancy in a Marmoset (Callithrix jacchus) Family Group in Captivity

One family group of common marmoset ( Callithrix jacchus ) was observed in captivity under natural environmental conditions to describe the circadian pattern of grooming behavior during the pregnancy of the reproductive female. The animals were observed by focal sampling, from the beginning to the end of animal's active phase, during two non-consecutive days per week, from August to November 1996. The duration of self-grooming and social grooming behavior of each animal were totalled each hour. The time series obtained were analyzed by Cluster Analysis and by Sin gle Cosinor Analysis. The daily patterns of grooming behavior during pregnancy were divided by Cluster Analysis into two stages, one corresponding to the second half of the third month of pregnancy, and the other from the last half of the third month to the last week before parturition. The confidence intervals of acrophases overlapped in all stages. The acrophases values of the first stage occurred between 10:09 h and 11:00 h, and on the second stage between 8:51 h and 11:13 h. The daily pattern of grooming behavior of adult male and female showed a trend to increase in the first hours of the active phase. This trend to advance grooming behavior during the second stage of pregnancy may be due to an effect of the coming parturition itself or to seasonal influences.     

Circadian Rhythmicity of Grooming Behavior During Pregnancy in a Marmoset (Callithrix jacchus) Family Group in Captivity

One family group of common marmoset (Callithrix jacchus) was observed in captivity under natural environmental conditions to describe the circadian pattern of grooming behavior during the pregnancy of the reproductive female. The animals were observed by focal sampling, from the beginning to the end of animal's active phase, during two non-consecutive days per week, from August to November 1996. The duration of self-grooming and social grooming behavior of each animal were totalled each hour. The time series obtained were analyzed by Cluster Analysis and by Sin gle Cosinor Analysis. The daily patterns of grooming behavior during pregnancy were divided by Cluster Analysis into two stages, one corresponding to the second half of the third month of pregnancy, and the other from the last half of the third month to the last week before parturition. The confidence intervals of acrophases overlapped in all stages. The acrophases values of the first stage occurred between 10:09 h and 11:00 h, and on the second stage between 8:51 h and 11:13 h. The daily pattern of grooming behavior of adult male and female showed a trend to increase in the first hours of the active phase. This trend to advance grooming behavior during the second stage of pregnancy may be due to an effect of the coming parturition itself or to seasonal influences.     

Regulatory mechanisms underlying novelty-induced grooming in the laboratory rat

Bouts of pelage cleaning can be readily evoked in laboratory rodents under conditions of exposure to novelty. Such novelty-induced grooming is described as stereotyped and rostro-caudal in its progression. The patterned structure of novelty-induced grooming makes it particularly attractive for research on the organizational and motivational underpinnings of co-ordinated behaviour. Micro-characteristics of stereotyped novelty-induced grooming bouts were studied in 27 female Wistar rats that were exposed to a novel arena with shelters for a period of 15 min. The order of grooming acts within the initial bouts was rostro-caudal, but subsequent bouts became progressively disorganized in their sequencing. The observed pattern of progressive bout disorganization may be attributed to the gradual dearousal from stress. Differences between consecutive bouts in their micro-characteristics suggest that at least some grooming actions emitted within the context of those bouts operate as relatively independent units of behaviour. Those unitary component actions appear to be integrated into protracted pelage cleaning sequences by a separate mechanism. Similar endogenous mechanisms have been proposed for other co-ordinated motor actions, which suggests that the organizational principles identified in the context of novelty-induced grooming may represent general principles that govern co-ordinated behaviour.     

Market powers predict reciprocal grooming in golden snub-nosed monkeys (Rhinopithecus roxellana)

Social grooming is a common form of affiliative behavior in primates. Biological market theory suggests that grooming can be traded either for grooming or other social commodities and services. When no other services are exchanged, grooming is predicted to be approximately reciprocated within a dyad. In contrast, the amount of reciprocal grooming should decrease as other offered services increase. We studied grooming patterns between polygamous male and female in golden snub-nosed monkeys (Rhinopithecus roxellana) from the Qinling Mountains of central China and found that about 29.7% of grooming bouts were reciprocated. However, the durations of grooming bouts offered and returned was asymmetrical within dyads. In bisexual dyads, more grooming was initiated by females than males, which became more pronounced as the number of females per one-male unit increased. The rate of copulation per day for each female was positively correlated with the total duration of grooming time females invested in males.. Females without an infant (non-mothers) directed more grooming towards females with an infant (mothers) and were significantly more likely to be non-reciprocated. There was a significant negative relationship between non-mother and mother grooming duration and the rate of infants per female in each one-male unit. High-ranking females also received more grooming from low-ranking females than vice versa. The rate of food-related aggressive interactions was per day for low-ranking females was negatively correlated with the duration of grooming that low-ranking females gave to high-ranking females. Our results showed that grooming reciprocation in R. roxellana was discrepancy. This investment-reciprocity rate could be explained by the exchange of other social services in lieu of grooming.     

Hemopoietic regulatory factors in human hemopoietic failures

There are two distinct hemopoietic activities in human serum that do not have the properties of the known hemopoietic lymphokines. These two activities appear not to be produced by immune competent cells. "Direct" stimulatory activity acts in primary target cultures of normal marrow. There does not appear to be a feedback mechanism between bone marrow failure and "direct" activity; it appears to reflect ongoing disease. Indirect "releaser" activity stimulates peripheral blood cells to produce hemopoietic growth factors. It is invariably elevated when release of hemopoietic growth factors is poor, indicating that a feedback mechanism exists. The peripheral blood cells of young patients, particularly young girls, respond poorly to autologous "releaser" stimulation. Results of treatment with ALG in this group are poor. However, all patients with aplastic anemia appear capable of producing adequate amounts "releaser" factor.     

Stress in Morphine-Addicted Rats: Antistressor Properties of Comenic Acid

In chronic experiments carried out on 128 rats we demonstrated that the withdrawal syndrome revealed in morphine-addicted animals is combined with the development of stress. This was reflected in an increase in the total duration of grooming behavior and in changes in its temporal pattern. In morphine-addicted animals, only the initial and final phases of the seven successive grooming phases remained clearly pronounced, whereas intermediate stages were lost. A recycling of the initial grooming stage, which could result in self-inflicted damage to the skin, was observed. Under conditions of complete discontinuation of morphine, disturbances of grooming were even intensified, and during 18 days after discontinuation of the drug such disturbances gradually disappeared. Injections of comenic acid against the background of discontinuation of morphine significantly accelerated the process of normalization of both the duration and pattern of grooming (9 days after discontinuation of the drug). In intact rats, comenic acid did not induce noticeable disturbances of grooming. We conclude that comenic acid possesses antistressor properties under conditions of the withdrawal syndrome.     

Effects of conduction delays on the existence and stability of one to one phase locking between two pulse-coupled oscillators

Gamma oscillations can synchronize with near zero phase lag over multiple cortical regions and between hemispheres, and between two distal sites in hippocampal slices. How synchronization can take place over long distances in a stable manner is considered an open question. The phase resetting curve (PRC) keeps track of how much an input advances or delays the next spike, depending upon where in the cycle it is received. We use PRCs under the assumption of pulsatile coupling to derive existence and stability criteria for 1:1 phase-locking that arises via bidirectional pulse coupling of two limit cycle oscillators with a conduction delay of any duration for any 1:1 firing pattern. The coupling can be strong as long as the effect of one input dissipates before the next input is received. We show the form that the generic synchronous and anti-phase solutions take in a system of two identical, identically pulse-coupled oscillators with identical delays. The stability criterion has a simple form that depends only on the slopes of the PRCs at the phases at which inputs are received and on the number of cycles required to complete the delayed feedback loop. The number of cycles required to complete the delayed feedback loop depends upon both the value of the delay and the firing pattern. We successfully tested the predictions of our methods on networks of model neurons. The criteria can easily be extended to include the effect of an input on the cycle after the one in which it is received.     

Age‐related activity patterns are moderated by diet in Queensland fruit flies Bactrocera tryoni

Life‐history parameters and the fitness of tephritid flies are closely linked to diet. Studies of locomotor behaviour can provide insights to these links, although little is known about how locomotor behaviour is influenced by diet. In the present study, video recordings of Queensland fruit flies Bactrocera tryoni Froggatt (Diptera: Tephritidae) (‘Q‐flies’) that are maintained individually in cages are used to determine how diet affects the activity patterns (flight, walking, grooming, inactivity) of males and females at ages ranging from 4 to 30 days. The frequency and total duration of activities over 10‐min trials are affected by diet, age and sex. Supplementation of diet with hydrolysed yeast results in a higher frequency and duration of flight in flies of all ages and both sexes. The effect of diet on other activities varies with age. Q‐flies fed sugar only increase walking frequency steadily from 4 to 30 days post‐eclosion, whereas flies fed sugar + yeast have higher walking frequencies at 4 and 10 days than flies fed sugar only, although they then exhibit a sharp decline at 30 days post‐eclosion. The frequency and duration of inactivity remain consistent in flies fed sugar + yeast, whereas flies fed sugar only exhibit a marked increase in inactivity from 4 to 30 days post‐eclosion. Compared with older flies, 4 day‐old Q‐flies fed sugar only spend considerably more time grooming. The potential of activity monitoring as a quality control test for flies that are mass‐reared for use in sterile insect technique programmes is discussed.     

Effects of thyroxine on the development of self-grooming behavior in rats

The effects of intraperitoneal thyroxine administration (1 microgram/body weight) on postnatal days 1-3 and the subsequent alterations upon the development of six self-grooming components were measured postnatally in male Wistar rats between days 1-60. Observations on self-grooming components showed that thyroxine-treated rats did not show consistent significant differences in the duration of grooming movements of short displacement directed to the forepaws and head throughout the study, as compared to controls. By contrast, after weaning, the duration of grooming movements of long displacement directed to the fur, genital area, and body scratching were significantly increased. The findings suggest that early thyroxine treatment may primarily interfere with the neural circuitry that modulate long displacement grooming movements, rather than with the substrates controlling short displacement grooming activities. Thus, the hormone might be acting upon neural modulatory systems of self-grooming having different vulnerability in relation to the level of maturity of the brain circuits underlying each grooming component.     

Delayed feedback and multiple attractors in a host–parasitoid system

 Continuous-time, age structured, host–parasitoid models exhibit three types of cyclic dynamics: Lotka–Volterra-like consumer-resource cycles, discrete generation cycles, and “delayed feedback cycles” that occur if the gain to the parasitoid population (defined by the number of new female parasitoid offspring produced per host attacked) increases with the age of the host attacked. The delayed feedback comes about in the following way: an increase in the instantaneous density of searching female parasitoids increases the mortality rate on younger hosts, which reduces the density of future older and more productive hosts, and hence reduces the future per head recruitment rate of searching female parasitoids. Delayed feedback cycles have previously been found in studies that assume a step-function for the gain function. Here, we formulate a general host–parasitoid model with an arbitrary gain function, and show that stable, delayed feedback cycles are a general phenomenon, occurring with a wide range of gain functions, and strongest when the gain is an accelerating function of host age. We show by examples that locally stable, delayed feedback cycles commonly occur with parameter values that also yield a single, locally stable equilibrium, and hence their occurrence depends on initial conditions. A simplified model reveals that the mechanism responsible for the delayed feedback cycles in our host–parasitoid models is similar to that producing cycles and initial-condition-dependent dynamics in a single species model with age-dependent cannibalism. Received: 24 October 1997 / Revised version: 13 June 1998     

Supply and Demand Determine the Market Value of Access to Infants in the Golden Snub-Nosed Monkey (Rhinopithecus roxellana)

According to a biological market paradigm, trading decisions between partners will be influenced by the current ‘exchange rate’ of commodities (good and services), which is affected by supply and demand, and the trader’s ability to outbid competitors. In several species of nonhuman primates, newborn infants are attractive to female group members and may become a desired commodity that can be traded for grooming within a biological market place. We investigated whether grooming was interchanged for infant handling in female golden snub-nosed monkeys (Rhinopithecus roxellana) inhabiting the Qinling Mountains of central China. R. roxellana exhibit a multilevel social organization characterized by over 100 troop members organized into 6–11 one-male units each composed one adult male and several adult females and their offspring. Behavioral data were collected over the course of 28 months on grooming patterns between mothers with infants less than 6 months old (N = 36) and other adult female troop members. Our results provide strong evidence for the interchange of grooming for access to infants. Grooming for infant access was more likely to be initiated by potential handlers (nonmothers) and less likely reciprocated by mothers. Moreover, grooming bout duration was inversely related to the number of infants per female present in each one-male unit indicating the possibility of a supply and demand market effect. The rank difference between mothers and handlers was negatively correlated with grooming duration. With increasing infant age, the duration of grooming provided by handlers was shorter suggesting that the ‘value’ of older infants had decreased. Finally, frequent grooming partners were allowed to handle and maintain access to infants longer than infrequent groomers. These results support the contention that grooming and infant handling may be traded in R. roxellana and that the price individuals paid for access to infants fluctuated with supply and demand.     

Antifouling adaptations of marine shrimp (Decapoda: Caridea): gill cleaning mechanisms and grooming of brooded embryos

Gills in the branchial chambers of caridean shrimps, as well as the brooded embryos in females, are subject to fouling by particulate debris and epizoites. Important mechanisms for cleaning the gills are brushing of the gills by the grooming or cleaning chelipeds in some species, while in others, setae from the bases of the thoracic legs brush up among the gills during movement of the limbs (epipodsetobranch complexes). Setae of cleaning chelipeds and of epipod-setobranch complexes show similar ultrastructural adaptions for scraping gill surfaces. Ablation of the cleaning chelipeds of the shrimp Heptacarpus pictus results in severe fouling of the gills in experimentals, while those of controls remain clean. Embryos brooded by female carideans are often brushed and jostled by the grooming chelipeds. In H. pictus , removal of the cleaning chelae results in heavier microbial and sediment fouling than in controls.     

Analysis of mechanical grooming at various frequencies on a large scale test panel coated with a fouling-release coating

A mechanical grooming test was performed on large scale steel test panels coated with a fouling-release (FR) coating (International Intersleek 900), at four different frequencies, during the high fouling season in Port Canaveral, Florida. Grooming at frequencies of three or two times per week was effective at removing heavy biofilm growth and significantly reduced macrofouling settlement. Mechanical grooming at lower frequencies of weekly or bi-weekly removed heavy biofilm growth but was much less effective at reducing macrofouling settlement. The results indicated that frequent mechanical grooming could reduce the fouling rating of ships coated with FR coatings. The reduction in the fouling rating of ships’ hulls by frequent grooming could offer significant reductions in drag, fuel consumption, and the emission of exhaust gases. Frequent grooming could also eliminate the need for hull cleaning and increase the time between dry docking which would reduce the operational costs for many vessel operators.     

A probabilistic model for the ultradian timing of REM sleep in mice

A salient feature of mammalian sleep is the alternation between rapid eye movement (REM) and non-REM (NREM) sleep. However, how these two sleep stages influence each other and thereby regulate the timing of REM sleep episodes is still largely unresolved. Here, we developed a statistical model that specifies the relationship between REM and subsequent NREM sleep to quantify how REM sleep affects the following NREM sleep duration and its electrophysiological features in mice. We show that a lognormal mixture model well describes how the preceding REM sleep duration influences the amount of NREM sleep till the next REM sleep episode. The model supports the existence of two different types of sleep cycles: Short cycles form closely interspaced sequences of REM sleep episodes, whereas during long cycles, REM sleep is first followed by an interval of NREM sleep during which transitions to REM sleep are extremely unlikely. This refractory period is characterized by low power in the theta and sigma range of the electroencephalogram (EEG), low spindle rate and frequent microarousals, and its duration proportionally increases with the preceding REM sleep duration. Using our model, we estimated the propensity for REM sleep at the transition from NREM to REM sleep and found that entering REM sleep with higher propensity resulted in longer REM sleep episodes with reduced EEG power. Compared with the light phase, the buildup of REM sleep propensity was slower during the dark phase. Our data-driven modeling approach uncovered basic principles underlying the timing and duration of REM sleep episodes in mice and provides a flexible framework to describe the ultradian regulation of REM sleep in health and disease.     

Studies on the excitability of the central program generator in the spinal cord of the terrapin Pseudemys scripta elegans

We present observations on the multicyclic scratch reflex in spinal terrapins as produced by electrical stimuli applied to the shell at the specific regions at which a mechanical stimulus produces the reflex. EMGs and hip and knee movements are recorded. The responses to the electrical stimuli are similar to the responses to mechanical stimuli. There is a three phase EMG pattern (Stein and Grossman, 1980), to which the movement pattern is related (Bakker and Crowe, 1982). A response may consist of a series of up to 25 movement cycles with a total time course of up to about 30 sec. The initial cycles of a response are relatively fast (less than 1 sec), but the cycles at the expiration of the response may have a duration of 2-3 sec. A single electrical stimulus pulse is often insufficient to trigger a series response. Instead, a weak EMG burst of a few tenths of a second duration, together with a slight movement, is often seen. However, a second pulse can set the cycle series in motion even after an interval of 40 sec between the pulses. A further booster stimulus pulse given while a reflex response is taking place can increase the speed of the movement. If the booster pulse is given just after cessation of reflex activity it can restart the activity, but this second cycle series is often shorter than the first one. The results indicate that the excitability of the central program generator is not constant. Long duration changes in the excitability are produced within the spinal cord.     

The energetic grooming costs imposed by a parasitic mite (Spinturnix myoti) upon its bat host (Myotis myotis)

Parasites often exert severe negative effects upon their host's fitness. Natural selection has therefore prompted the evolution of anti-parasite mechanisms such as grooming. Grooming is efficient at reducing parasitic loads in both birds and mammals, but the energetic costs it entails have not been properly quantified. We measured both the energetic metabolism and behaviour of greater mouse-eared bats submitted to three different parasite loads (no, 20 and 40 mites) during whole daily cycles. Mites greatly affected their time and energy budgets. They caused increased grooming activity, reduced the overall time devoted to resting and provoked a dramatic shortening of resting bout duration. Correspondingly, the bats' overall metabolism (oxygen consumption) increased drastically with parasite intensity and, during the course of experiments, the bats lost more weight when infested with 40 rather than 20 or no parasites. The short-term energetic constraints induced by anti-parasite grooming are probably associated with long-term detrimental effects such as a decrease in survival and overall reproductive value.     

Effect of genotype and emotional stress on hygienic grooming in inbred mice

Body care behavior (grooming) is an adaptation aimed at removing litter particles, pathogenic microbes and parasites from animal fur and skin. Moreover, it serves as an indicator of animal health. It was observed that chronic stress suppressed fur cleaning. In this article, a technique of direct measurement of fur cleaning using the cleaning dynamics of a fluorescent spot applied on animal's back is described. Significant effects of genotype and emotional stress on the dynamics of fur cleaning are shown. Mice of C57BL/6, CBA and CC57BR strains clean green fluorescent spot rapidly (1-2 h) whereas animals of AKR strain clean it slowly (up to 24 h). Behavioral restriction for 30 min substantially reduced fur cleaning in AKR, CBA and CC57BR, but not in C57BL/6. The stress-induced attenuation of Hygienic grooming is a new index of sensitivity (resistance) to stress.