Primate

About: Primate is a research topic. Over the lifetime, 1250 publications have been published within this topic receiving 67388 citations. The topic is also known as: the primate order & primates.

BMAL1 knockout macaque monkeys display reduced sleep and psychiatric disorders

Abstract: Circadian disruption is a risk factor for metabolic, psychiatric and age-related disorders, and non-human primate models could help to develop therapeutic treatments. Here, we report the generation of BMAL1 knockout cynomolgus monkeys for circadian-related disorders by CRISPR/Cas9 editing of monkey embryos. These monkeys showed higher nocturnal locomotion and reduced sleep, which was further exacerbated by a constant light regimen. Physiological circadian disruption was reflected by the markedly dampened and arrhythmic blood hormonal levels. Furthermore, BMAL1-deficient monkeys exhibited anxiety and depression, consistent with their stably elevated blood cortisol, and defective sensory processing in auditory oddball tests found in schizophrenia patients. Ablation of BMAL1 up-regulated transcriptional programs toward inflammatory and stress responses, with transcription networks associated with human sleep deprivation, major depressive disorders, and aging. Thus, BMAL1 knockout monkeys are potentially useful for studying the physiological consequences of circadian disturbance, and for developing therapies for circadian and psychiatric disorders.

Prenatal stress alters brain biogenic amine levels in primates

Abstract: In this study, we assessed behavioral responses to social separation at 8 months of age and cerebrospinal fluid (CSF) concentrations of biogenic amines and metabolites at 8 and 18 months of age in 12 rhesus monkeys derived from either stressed or undisturbed pregnancies. Compared to controls from undisturbed pregnancies, prenatal stress-derived monkeys had higher concentrations of 3-methoxy-4-hydroxyphenylglycol (MHPG), and 3,4-dihydroxyphenylacetic acid in CSF than controls. Norepinephrine and MHPG response to stress were both correlated between 8 and 18 months of age. There were few group differences in behavior during social separation; however, several behavioral differences between groups were found when monkeys were reunited with cage mates. Prenatally stressed monkeys spent more time clinging to their surrogates and exploring (including eating and drinking), while controls showed more locomotion and social play with their cage mates. Collectively, our findings suggest that chronic unpredictable psychological stress during pregnancy has long-lasting effects on noradrenergic and dopaminergic activity and behavior in the offspring of gestationally stressed primate mothers.

A complete skeleton of the giant South American primate Protopithecus

Abstract: A COMPLETE skeleton of a large-bodied New World monkey has been found in Pleistocene cave deposits in the Brazilian state of Bahia. It demonstrates an unprecedented combination of body size, locomotor and cranial morphology. Skeletal features indicate an animal of approximately 25 kg, more than twice the mass of any living South American monkey. We refer the specimen to Protopithecus brasiliensis Lund, 1838, a large Pleistocene primate originally represented by only a proximal femur and distal humerus1–4. The skeleton resembles species of two distinct New World monkey lineages. The cranium is modified for an enlarged vocal sac typical of living howler monkeys5–7, and the postcranium includes suspensory and brachiating components of locomotion as seen in living spider and woolly spider monkeys8. This skeleton confirms that adaptive diversity in neotropical primates was greater in the recent past, and that current interpretations of how their distinctive adaptations evolved should be revised.

Ranging Behavior of Two Species of Guenons (Cercopithecus lhoesti and C. mitis doggetti ) in the Nyungwe Forest Reserve, Rwanda

Abstract: I studied the ranging behavior of one group of L'Hoest's monkeys (Cercopithecus lhoesti) and one group of blue monkeys (C. mitis doggetti) in the Nyungwe Forest Reserve, Rwanda. This study is the first to examine the ranging behavior of the more terrestrial L'Hoest's monkeys. Fruits composed 47% of blue monkey diet and 24% of the L'Hoest's monkey diet; terrestrial herbaceous vegetation composed 35% of the diet of the latter. While overall abundance of fruit resources in the home range and overall proportion of fruit in the diet were not related to ranging behavior in either group, temporal and spatial availability of specific fruit species was related. Measures of ranging behavior indicated a more concentrated ranging pattern when fruit resources were scarce and dietary diversity increased and when fruit resources were abundant and the groups focused on a few abundant fruit species. Current hypotheses concerning primate ranging behavior suggest that frugivorous species are expected to have greater day ranges and larger home ranges than folivorous species, and invertebrate consumption is expected to produce a more wide-ranging pattern. However, the L'Hoest's monkey group, which was more folivorous and consumed fewer invertebrates, traveled greater daily distances, had a more diverse and longer ranging pattern, and had larger home range areas than the blue monkey group in every month of the study. Both species were highly selective of forest habitats; L'Hoest's monkeys used secondary forest, while blue monkeys preferred primary forest.