实验恒河猴超声心动图的初步研究

分别采用二维、脉冲多普勒及M型超声心动图Teichholtz公式对1 0只健康成年实验恒河猴(Macacamulatta)的心脏结构、心脏血流动力学及左室收缩功能进行测定,并比较不同性别间各参数的差异,以建立正常健康成年恒河猴超声心动图相关生理学参数的基础正常值。结果表明,健康成年实验恒河猴超声心动图各项生理指标类似于人类新生儿的指标,雌、雄组间比较除室间隔舒张末期厚度有统计学差异外(P <0 0 5 ) ,其余指标均无统计学差异(P >0 0 5 )。     

Aggressive Play and Communication in Rhesus Monkeys (Macaca mulatta)

One adaptive function that has been suggested for social playin higher primates is the learning, refining, or practicingof communicative skills. Despite the absence of experimentaldata, a comparison of the structure of aggressive play and communicationmay shed light on this hypothesis. The great majority of rhesusmonkey agonistic interactions are mediated by stereotyped signals.Deprivation experiments have shown that appropriate interpretationand use of such signals requires early social experience. Suchexperience seemingly must have the following characteristics:(i) The relevant agonistic signals must occur, (ii) These signalsmust regularly be paired with other stimuli for appropriateresponses to signals to be learned. Signals must produce regularresponses in other monkeys for appropriate use to be learned.Aggressive play seems to be an unpromising context in whichto learn, refine, or practice agonistic signals. These signalsare not observed in play, and the signals that do occur arerestricted to play and are not regularly paired with unconditionedstimuli.     

猕猴精子优选及体外获能的研究

选择活率高的精子并进行体外获能是开展猕猴体外受精研究的必要程序, 是研究猕猴受精生物学的重要手段。本实验采用上浮法和Percoll 梯度离心法对猕猴精液进行了优选, 并对处理后的精子形态正常率、精子活率、密度及受精率作了比较, 发现二者差异不显著; 用dbcAMP 和咖啡因使精子获能, 发现只有两种获能剂同时存在才能使猕猴精子获能并使卵母细胞受精。结论为: 上浮法和Percoll 法都是有效的精子优选法, 对受精率的影响差异不显著; dbcAMP 和咖啡因在猕猴精子体外获能时缺一不可。     

Glycosylated Haemoglobin (Hb A1) in Normal Rhesus Monkeys (Macaca mulatta)

Glycosylated haemoglobins were measured in 23 healthy juvenile rhesus monkeys by the use of commercially available minicolumn chromatography (Quick Sep., Isolab Inc., Ohio, USA) to establish the normal range. Values obtained (mean ± 1 standard deviation (SD) 1.57 ± 0.68%) were significantly lower than that of 17 adult healthy human volunteers by the use of the same method of estimation (mean ± 1 SD of 5.34 ± 0.78%).     

A Behavioral Taxonomy of Loneliness in Humans and Rhesus Monkeys (Macaca mulatta)

Social relationships endow health and fitness benefits, but considerable variation exists in the extent to which individuals form and maintain salutary social relationships. The mental and physical health effects of social bonds are more strongly related to perceived isolation (loneliness) than to objective social network characteristics. We sought to develop an animal model to facilitate the experimental analysis of the development of, and the behavioral and biological consequences of, loneliness. In Study 1, using a population-based sample of older adults, we examined how loneliness was influenced both by social network size and by the extent to which individuals believed that their daily social interactions reflected their own choice. Results revealed three distinct clusters of individuals: (i) individuals with large networks who believed they had high choice were lowest in loneliness, (ii) individuals with small social networks who believed they had low choice were highest in loneliness, and (iii) the remaining two groups were intermediate and equivalent in loneliness. In Study 2, a similar three-group structure was identified in two separate samples of adult male rhesus monkeys (Macaca mulatta) living in large social groups: (i) those high in sociability who had complex social interaction with a broad range of social partners (putatively low in loneliness), (ii) those low in sociability who showed tentative interactions with certain classes of social partners (putatively high in loneliness), and (iii) those low in sociability who interacted overall at low levels with a broad range of social partners (putatively low or intermediate in loneliness). This taxonomy in monkeys was validated in subsequent experimental social probe studies. These results suggest that, in highly social nonhuman primate species, some animals may show a mismatch between social interest and social attainment that could serve as a useful animal model for experimental and mechanistic studies of loneliness.     

Sneaky Monkeys: An Audience Effect of Male Rhesus Macaques (Macaca mulatta) on Sexual Behavior

Males and females have different sexual interests and subsequently may show conflicting sexual strategies. While dominant males try to monopolize females, promiscuity benefits females and subordinate males. One way to escape monopolization by dominant males is to copulate in their absence. We tested this inhibitory effect of males on the sexual behavior of their group members in captive group‐living Rhesus macaques. Copulations between females and nonalpha males almost exclusively took place when the alpha male was out of sight. Furthermore, the inhibiting effect was not unique for the alpha male. An upcoming nonalpha male also inhibited copulations of its group members, and three other nonalpha males inhibited female copulation solicitations. Females adjusted their behavior to the presence of bystander males, as they initiated and accepted initiations more often in absence than in presence of bystander males. Although not significant, in males, a similar pattern was found. The observed reduction in mating behavior in presence of bystander males is in accordance with an “audience effect,” in which the behavior is modulated in relation to the presence or absence of third parties. This audience effect may serve as an important mechanism to reduce (aggressive) interruptions of subordinate male copulations.     

Development of a Cerebrospinal Fluid Lateral Reservoir Model in Rhesus Monkeys (Macaca mulatta)

Rapid, serial, and humane collection of cerebrospinal fluid (CSF) in nonhuman primates (NHP) is an essential element of numerous research studies and is currently accomplished via two different models. The CSF reservoir model (FR) combines a catheter in the 4th ventricle with a flexible silastic reservoir to permit circulating CSF flow. The CSF lateral port model (LP) consists of a lateral ventricular catheter and an IV port that provides static access to CSF and volume restrictions on sample collection. The FR model is associated with an intensive, prolonged recovery and frequent postsurgical hydrocephalus and nonpatency, whereas the LP model is associated with an easier recovery. To maximize the advantages of both systems, we developed the CSF lateral reservoir model (LR), which combines the beneficial features of the 2 previous models but avoids their limitations by using a reservoir for circulating CSF flow combined with catheter placement in the lateral ventricle. Nine adult male rhesus monkeys were utilized in this study. Pre-surgical MRI was performed to determine the coordinates of the lateral ventricle and location of choroid plexus (CP). The coordinates were determined to avoid the CP and major blood vessels. The predetermined coordinates were 100% accurate, according to MRI validation. The LR system functioned successfully in 67% of cases for 221 d, and 44% remain functional at 426 to 510 d postoperatively. Compared with established models, our LR model markedly reduced postoperative complications and recovery time. Development of the LR model was successful in rhesus macaques and is a useful alternative to the FR and LP methods of CSF collection from nonhuman primates.Abbreviations: CP, choroid plexus; FR, CSF 4th ventricular reservoir model; LP, CSF lateral port model; LR, CSF lateral reservoir model; SER, successful establishment rateSerial ventricular CSF sampling in NHP is a frequent and critical requirement for a wide variety of studies and is predominantly accomplished by using either of 2 models. The 4th ventricle (FR) model, previously referred to as an Ommaya reservoir,⁶ and lateral port (LP) models² are closed, indwelling, subcutaneous systems that allow for serial, rapid, and humane collection of CSF, as well as intraventricular drug administration, in unanesthetized and restrained NHP.The FR model (Figure 1 A) consists of a catheter that is placed in the 4th ventricle and attached to a silastic reservoir that is implanted subcutaneously over the occipital bone. The silastic reservoir is depressed repetitively prior to and after sampling to circulate the CSF throughout the ventricles and catheter system to provide an unbiased sample without volume loss to dead space. The reservoir is accessed percutaneously to obtain a CSF sample via aspiration or to administer drug. The FR model initially was developed in 1977⁶ and continues to be used for pharmacokinetic studies. This system continues to demonstrate a low rate of successful establishment, but once established, the FR model remains patent for prolonged periods without evidence of neurologic sequelae or bleeding from the choroid plexus (CP) in rhesus macaques. The decreased establishment rate of this model is attributed, at least in part, to postsurgical development of hydrocephalus, given that the catheter, which is routed through the aqueduct of Magendie to the 4th ventricle, can obstruct the flow of CSF. In addition, maintaining catheter patency is problematic due to CP bleeding during the recovery period. Postsurgical care and recovery after creating the FR are extensive, frequently requiring prolonged analgesics and steroid administration, with many days needed for complete recovery.Open in a separate windowFigure 1.Evolution of CSF ventricular models, with flow dynamics. (A) Sagittal diagram of original FR (Ommaya) model, with placement in the 4th ventricle. Developed in 1977. Arrows indicate the circulating flow of CSF. (B) Original LP model, with catheter placement in the lateral ventricle and attachment to an IV access port. Developed in 1990. Arrows indicate the static, unidirectional flow of CSF. (C) The LR model, a composite of the 2 earlier CSF models. Arrows indicate the circulating flow of CSF.The LP model (Figure 1 B) consists of a catheter that is implanted in the lateral ventricle and attached to a subcutaneous intravenous access port. The port is accessed percutaneously to obtain the CSF sample or to administer a drug. The LP is a static model, because the CSF is not circulated or mixed through the ventricles, and CSF is obtained via unidirectional flow. The LP model was developed in 1990 for intrathecal drug administration³ and has been used subsequently for CSF collection⁴ by several investigators. CSF sampling with the LP model is restrictive: the volume of the system (that is, the dead space) must be removed at each collection to obtain an unbiased sample, collection is accomplished via gravitational flow and not aspiration, and the collection frequency is dependent on the rate of CSF replacement. In addition, the potential for sample contamination from blood due to CP bleeding remains problematic for the duration of LP implantation. However, the use of the lateral ventricle avoids the postsurgical complication of hydrocephalus. This system demonstrated a high rate of successful establishment with a reduction in the necessary analgesic and steroid administration as well as days to complete recovery, as compared with the FR model. Analysis of our clinical records from 2003 to 2013 revealed a successful establishment rate (SER) of 39% for the FR model; 33% of these systems remained functional for 3 to 7.5 y (

Rhesus Monkeys (Macaca mulatta) Detect Rhythmic Groups in Music,but Not the Beat

It was recently shown that rhythmic entrainment, long considered a human-specific mechanism, can be demonstrated in a selected group of bird species, and, somewhat surprisingly, not in more closely related species such as nonhuman primates. This observation supports the vocal learning hypothesis that suggests rhythmic entrainment to be a by-product of the vocal learning mechanisms that are shared by several bird and mammal species, including humans, but that are only weakly developed, or missing entirely, in nonhuman primates. To test this hypothesis we measured auditory event-related potentials (ERPs) in two rhesus monkeys (Macaca mulatta), probing a well-documented component in humans, the mismatch negativity (MMN) to study rhythmic expectation. We demonstrate for the first time in rhesus monkeys that, in response to infrequent deviants in pitch that were presented in a continuous sound stream using an oddball paradigm, a comparable ERP component can be detected with negative deflections in early latencies (Experiment 1). Subsequently we tested whether rhesus monkeys can detect gaps (omissions at random positions in the sound stream; Experiment 2) and, using more complex stimuli, also the beat (omissions at the first position of a musical unit, i.e. the ‘downbeat’; Experiment 3). In contrast to what has been shown in human adults and newborns (using identical stimuli and experimental paradigm), the results suggest that rhesus monkeys are not able to detect the beat in music. These findings are in support of the hypothesis that beat induction (the cognitive mechanism that supports the perception of a regular pulse from a varying rhythm) is species-specific and absent in nonhuman primates. In addition, the findings support the auditory timing dissociation hypothesis, with rhesus monkeys being sensitive to rhythmic grouping (detecting the start of a rhythmic group), but not to the induced beat (detecting a regularity from a varying rhythm).     

Absence of Naturally Acquired Tetanus Antitoxin in the Free-Ranging Cayo Santiago Rhesus Monkeys (Macaca mulatta)

Tetanus is enzootic in the free-ranging rhesus monkey colony on Cayo Santiago. The disease accounts for 25% of all mortalities in the population. The high prevalence of tetanus provided a unique opportunity to study the potential roles of geophagia, wounding, and clinical tetanus infections on the development of naturally acquired tetanus antitoxin in rhesus macaques. Eighty-six unvaccinated monkeys, including six that recovered from tetanus, were serosurveyed using a mouse toxin neutralization test. None of the animals had detectable antitoxin titers (<0.001 AU/ml), suggesting that natural immunity to tetanus is either rare or nonexistent in the Cayo Santiago colony.     

Extraintestinal Campylobacteriosis in Rhesus Macaques (Macaca mulatta)

Two cases of clinical disease associated with extraintestinal Campylobacter infection were recently encountered in rhesus macaques (Macaca mulatta). The first case was that of a 3-y-old, male, rhesus macaque experimentally infected with SIV, who presented with abdominal pain and a midabdominal mass and was euthanized. Pathology findings included an abscess within the median liver lobe, fibrinopurulent peritonitis, and intestinal serositis with isolation of Campylobacter fetus from the blood, liver, and the hepatic abscess. The second case was that of a 1-mo-old, female, rhesus macaque who died with no apparent history of illness. Gross pathology findings included thin body condition and diarrheic staining of the perineum; histologically, acute multifocal hepatitis with intralesional bacteria was noted. Campylobacter coli was isolated from the liver and colon. Extraintestinal Campylobacter infection is uncommon in humans, usually occurring in immunocompromised subjects and most commonly manifesting as bacteremia. Extraintestinal Campylobacter infections in animals are rare but have been associated with bacteremia and cholecystitis. The macaques presented here were either immunocompromised due to SIV infection (case 1) or more vulnerable due to young age (case 2). These factors likely contributed to the extraintestinal spread of Campylobacter.Campylobacter spp. are curved or spiral, gram-negative, microaerobic, typically motile bacteria with a single flagellum at one or both ends of the cell.²⁵ Campylobacter is one of the most common bacterial causes of gastroenteritis in humans worldwide.³ The Centers for Disease Control and Prevention estimate it to affect more than 1.3 million people in the United States each year.¹¹ Campylobacter spp. colonize the intestinal tract of primates, other mammals, birds, reptiles, and shellfish, but infection is not always associated with clinical signs of disease.^2,23 Contaminated or undercooked poultry represents the largest potential source of human infection.²² Campylobacteriosis is a zoonosis, and other significant sources of human infection include livestock, wildlife, pets, and contaminated water.²² The species most commonly isolated from humans and nonhuman primates are C. jejuni and C. coli; other species like C. fetus are less commonly found.^2,4,9,23 Extraintestinal campylobacteriosis in humans usually occurs in immunocompromised or elderly persons with underlying medical problems and most commonly manifests as bacteremia.²³ There have been a few reports of extraintestinal Campylobacter infections in animals, including bacteremia and cholecystitis in 2 dogs.^17,30     

Osteochondromatosis in a Rhesus macaque (Macaca mulatta)

A 5-y-old, male, rhesus macaque (Macaca mulatta) presented with a prominent mass slightly anteriomedial to the right stifle. On exam, multiple radiopaque masses were identified protruding from the mid- and distal femur. Lateral and anteroposterior radiographs of the right stifle region revealed multiple exophytic masses arising from the femur, with mild bony reaction of the proximal tibia. Histologic examination of biopsy tissue revealed woven and lamellar bone with granulation tissue and skeletal muscle. Because the macaque was exhibiting no lameness or signs of pain, we decided to monitor the progression of the masses. Minimal change was noted during the time prior to study termination at 6.5 y of age. Necropsy revealed that the bony masses were cartilage-capped lesions arising near the growth plate of the distal femur and midshaft of the femur and tibia. Histologic examination revealed chondro-osseous exophytic growths that blended imperceptibly with the cortex and spongiosa of the femur, consistent with a final diagnosis of multiple osteochondromas.     

Dominance in assamese macaques (Macaca assamensis)

A field study of 64 assamese macaques (Macaca assamensis) was conducted at a temple site in Assam, India. Focal and all occurrence scan techniques were used to collect data on agonistic, grooming, and sexual behavior. More than 1,000 hr of data were summarized into agonistic dominance, grooming, and mounting matrices. Rank hierarchies were constructed for all three and compared. We also directly compared each cell in each matrix with the corresponding cells in the other matrices. A nearly linear agonistic dominance hierarchy was found, but it did not correlate with the directionality of mounting or grooming. Adult males mounted females, generally were dominant to females and groomed females more often than they were groomed by females. Younger males groomed older males and were also generally subordinate to older males. These age and sex effects produced some inter‐correlations among grooming, mounting, and dominance but only for specific age‐sex classes. Theoretical models of social exchange were not considered useful in predicting the complex patterns of grooming, mounting, and dominance seen in the present group. Whereas such models may "explain" existing data for some groups and have gained widespread acceptance, they must be empirically tested. Am. J. Primatol. 48:283–289, 1999. © 1999 Wiley‐Liss, Inc.     

Maternal Anxiety in Rhesus Macaques (Macaca mulatta)

Visual monitoring and scratching were used as behavioral indicators of maternal and social anxiety in small captive groups of rhesus macaques. Young infants were especially at risk from other group members during the first weeks of locomotion away from their mothers. Mothers received aggression from other individuals irrespective of their infants' presence or absence. The rate at which mothers scratched themselves increased significantly when their infants moved away from them and when the infants approached or were approached by individuals who frequently harassed them. The rate of maternal scratching and the rate of glancing at the infant and at other individuals when the infant was away decreased as infants grew older and became less vulnerable to harassment. In contrast, the rate of maternal scratching and visual monitoring of other individuals when the infant was in contact remained stable across the first 12 wk of lactation. The rate of maternal scratching increased when the mother-infant pair was in spatial proximity to the adult male or higher ranking adult females. Although visual monitoring and scratching showed a similar sensitivity to social variables, it is speculated that they might reflect different components of anxiety, namely, anticipation of danger and uncertainty due to motivational conflict. The results of this investigation indicate that a macaque mother's emotional reactivity to a perceived danger for herself and her infant can be measured quite accurately using the rates of visual monitoring and scratching and that the latter represent reliable tools to investigate the emotional correlates of maternal behavior in nonhuman primates.     

Mineralized Trichobezoars in a Rhesus Macaque (Macaca mulatta)

A five-year-old female rhesus macaque (Macaca mulatta) presented with a thin body condition and multiple palpable mid-abdominal masses. Mineralized cecal trichobezoars were removed surgically. Thirteen months later, similar masses recurred and were confirmed with radiographs. This is the first case report of a mineralized cecal trichobezoar in a rhesus macaque.     

Neonatal temperament and neuromotor differences are predictive of adolescent alcohol intake in rhesus monkeys (Macaca mulatta)

Identifying predictors of teenage alcohol use disorder (AUDs) is a major health initiative, with studies suggesting that there are distinct personality-related traits that underlie patterns of alcohol intake. As temperament is biologically based, identifiable early in life, and stable across time, it is considered the foundation of personality. As such, we hypothesized that neonatal temperament traits would predict anxiety-mediated adolescent alcohol consumption. To test this, N = 145 rhesus macaque (Macaca mulatta) infants (14 days of age), reared in a neonatal nursery (n = 82) or in a control condition with their mothers (n = 63) were assessed with a widely used standardized nonhuman primate testing battery, the Infant Behavioral Assessment Scale (IBAS), modeled after the Brazelton Neonatal Assessment Scale, evaluating visual orienting, temperament, motor maturity and, more recently, sensory sensitivity. As adolescents (3–4 years of age), these same subjects were allowed unfettered access to a sweetened-alcohol solution for 1 hr/day, 4 days/week, over 5–7 weeks. Subjects were allowed to self-administer alcohol while housed alone (n = 70) or socially in their home cage (n = 55). Linear regressions showed that alcohol intake was predicted by neonatal orienting ability (β = −.35; p = .01), state control (β = −.19; p = .04), and motor maturity (β = −.24; p = .01). Poor neonatal orienting, state control (ease of consolability), and motor maturity were associated with higher adolescent alcohol intake in rhesus monkeys. These findings suggest that neonatal temperament is predictive of patterns of adolescent alcohol intake. To the extent that these results generalize to humans, they provide evidence that early-life temperament and neurodevelopment may be important risk factors for adolescent AUDs and that the IBAS may be used as an assessment tool for identifying such risk.     

Rhesus Monkeys (Macaca mulatta) Do Recognize Themselves in the Mirror: Implications for the Evolution of Self-Recognition

Self-recognition in front of a mirror is used as an indicator of self-awareness. Along with humans, some chimpanzees and orangutans have been shown to be self-aware using the mark test. Monkeys are conspicuously absent from this list because they fail the mark test and show persistent signs of social responses to mirrors despite prolonged exposure, which has been interpreted as evidence of a cognitive divide between hominoids and other species. In stark contrast with those reports, the rhesus monkeys in this study, who had been prepared for electrophysiological recordings with a head implant, showed consistent self-directed behaviors in front of the mirror and showed social responses that subsided quickly during the first experimental session. The self-directed behaviors, which were performed in front of the mirror and did not take place in its absence, included extensive observation of the implant and genital areas that cannot be observed directly without a mirror. We hypothesize that the head implant, a most salient mark, prompted the monkeys to overcome gaze aversion inhibition or lack of interest in order to look and examine themselves in front of the mirror. The results of this study demonstrate that rhesus monkeys do recognize themselves in the mirror and, therefore, have some form of self-awareness. Accordingly, instead of a cognitive divide, they support the notion of an evolutionary continuity of mental functions.     

Evidence in Female Rhesus Monkeys (Macaca mulatta) that Nighttime Caloric Intake is not Associated with Weight Gain

Objective: To evaluate the hypothesis that nighttime consumption of calories leads to an increased propensity to gain weight. Research Methods and Procedures: Sixteen female rhesus monkeys (Macaca mulatta) were ovariectomized and placed on a high‐fat diet to promote weight gain, and we examined whether monkeys that ate a high percentage of calories at night were more likely to gain weight than monkeys that ate the majority of calories during the day. Results: Within 6 weeks post‐ovariectomy, calorie intake and body weight increased significantly (129 ± 14%, p = 0.04; 103 ± 0.91%, p = 0.02, respectively). Subsequent placement on high‐fat diet led to further significant increases in calorie intake and body weight (368 ± 56%, p = 0.001; 113 ± 4.0%, p = 0.03, respectively). However, there was no correlation between the increase in calorie intake and weight gain (p = 0.34). Considerable individual variation existed in the percentage of calories consumed at night (6% to 64% total daily caloric intake). However, the percentage of calorie intake occurring at night was not correlated with body weight (r = 0.04; p = 0.87) or weight gain (r = 0.07; p = 0.79) over the course of the study. Additionally, monkeys that showed the greatest nighttime calorie intake did not gain more weight (p = 0.94) than monkeys that showed the least nighttime calorie intake. Discussion: These results show that eating at night is not associated with an increased propensity to gain weight, suggesting that individuals trying to lose weight should not rely on decreasing evening calorie intake as a primary strategy for promoting weight loss.