Macaca mulatta: A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.Monkey Diseases: Diseases of Old World and New World monkeys. This term includes diseases of baboons but not of chimpanzees or gorillas (= APE DISEASES).Macaca: A genus of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, consisting of 16 species inhabiting forests of Africa, Asia, and the islands of Borneo, Philippines, and Celebes.Macaca fascicularis: A species of the genus MACACA which typically lives near the coast in tidal creeks and mangrove swamps primarily on the islands of the Malay peninsula.Macaca nemestrina: A species of the genus MACACA which inhabits Malaya, Sumatra, and Borneo. It is one of the most arboreal species of Macaca. The tail is short and untwisted.Macaca radiata: A species of macaque monkey that mainly inhabits the forest of southern India. They are also called bonnet macaques or bonnet monkeys.Haplorhini: A suborder of PRIMATES consisting of six families: CEBIDAE (some New World monkeys), ATELIDAE (some New World monkeys), CERCOPITHECIDAE (Old World monkeys), HYLOBATIDAE (gibbons and siamangs), CALLITRICHINAE (marmosets and tamarins), and HOMINIDAE (humans and great apes).Primate Diseases: Diseases of animals within the order PRIMATES. This term includes diseases of Haplorhini and Strepsirhini.Animals, LaboratoryPlasmodium cynomolgi: A protozoan parasite that occurs naturally in the macaque. It is similar to PLASMODIUM VIVAX and produces a type of malaria similar to vivax malaria (MALARIA, VIVAX). This species has been found to give rise to both natural and experimental human infections.Sperm Agglutination: Agglutination of spermatozoa by antibodies or autoantibodies.Retroviruses, Simian: Classes of retroviruses for which monkeys or apes are hosts. Those isolated from the West African green monkey and the Asian rhesus macaque monkey are of particular interest because of their similarities to viruses causing cancer and acquired immunodeficiency syndrome (AIDS) in humans.Social Dominance: Social structure of a group as it relates to the relative social rank of dominance status of its members. (APA, Thesaurus of Psychological Index Terms, 8th ed.)Euthanasia, Animal: The killing of animals for reasons of mercy, to control disease transmission or maintain the health of animal populations, or for experimental purposes (ANIMAL EXPERIMENTATION).Housing, AnimalSpecies Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Simian Acquired Immunodeficiency Syndrome: Acquired defect of cellular immunity that occurs naturally in macaques infected with SRV serotypes, experimentally in monkeys inoculated with SRV or MASON-PFIZER MONKEY VIRUS; (MPMV), or in monkeys infected with SIMIAN IMMUNODEFICIENCY VIRUS.Cebus: A genus of the family CEBIDAE, subfamily CEBINAE, consisting of four species which are divided into two groups, the tufted and untufted. C. apella has tufts of hair over the eyes and sides of the head. The remaining species are without tufts - C. capucinus, C. nigrivultatus, and C. albifrons. Cebus inhabits the forests of Central and South America.Pan troglodytes: The common chimpanzee, a species of the genus Pan, family HOMINIDAE. It lives in Africa, primarily in the tropical rainforests. There are a number of recognized subspecies.Simian immunodeficiency virus: Species of the genus LENTIVIRUS, subgenus primate immunodeficiency viruses (IMMUNODEFICIENCY VIRUSES, PRIMATE), that induces acquired immunodeficiency syndrome in monkeys and apes (SAIDS). The genetic organization of SIV is virtually identical to HIV.Discrimination Learning: Learning that is manifested in the ability to respond differentially to various stimuli.Pitheciidae: A family of New World monkeys in the infraorder PLATYRRHINI consisting of two subfamilies: Callicebinae and Pitheciinae.Behavior, Animal: The observable response an animal makes to any situation.Atelinae: A subfamily in the family ATELIDAE, comprising three genera: woolly monkeys (Lagothrix), spider monkeys (Ateles), and woolly spider monkeys (Brachyteles).Sexual Maturation: Achievement of full sexual capacity in animals and in humans.Oesophagostomum: A genus of nematodes of the superfamily STRONGYLOIDEA, parasitic in the intestines of animals. The adults are usually free in the intestinal lumen; the larvae encyst in the wall.Clorazepate Dipotassium: A water-soluble benzodiazepine derivative effective in the treatment of anxiety. It has also muscle relaxant and anticonvulsant actions.Osteochondromatosis: A condition marked by the presence of multiple osteochondromas. (Dorland, 27th ed)Papio: A genus of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, consisting of five named species: PAPIO URSINUS (chacma baboon), PAPIO CYNOCEPHALUS (yellow baboon), PAPIO PAPIO (western baboon), PAPIO ANUBIS (or olive baboon), and PAPIO HAMADRYAS (hamadryas baboon). Members of the Papio genus inhabit open woodland, savannahs, grassland, and rocky hill country. Some authors consider MANDRILLUS a subgenus of Papio.Thermometry: Measurement of the temperature of a material, or of the body or an organ by various temperature sensing devices which measure changes in properties of the material that vary with temperature, such as ELASTICITY; MAGNETIC FIELDS; or LUMINESCENCE.PrimatesTupaia: A genus of tree shrews of the family TUPAIIDAE which consists of about 12 species. One of the most frequently encountered species is T. glis. Members of this genus inhabit rain forests and secondary growth areas in southeast Asia.Callosities: Localized hyperplasia of the horny layer of the epidermis due to pressure or friction. (Dorland, 27th ed)Herpesvirus 1, Cercopithecine: A species of SIMPLEXVIRUS that causes vesicular lesions of the mouth in monkeys. When the virus is transmitted to man it causes an acute encephalitis or encephalomyelitis, which is nearly always fatal.Testis: The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.Saimiri: A genus of the family CEBIDAE consisting of four species: S. boliviensis, S. orstedii (red-backed squirrel monkey), S. sciureus (common squirrel monkey), and S. ustus. They inhabit tropical rain forests in Central and South America. S. sciureus is used extensively in research studies.Microsporida: An order of parasitic FUNGI found mostly in ARTHROPODS; FISHES; and in some VERTEBRATES including humans. It comprises two suborders: Pansporoblastina and APANSPOROBLASTINA.Concept Formation: A cognitive process involving the formation of ideas generalized from the knowledge of qualities, aspects, and relations of objects.Grooming: An animal's cleaning and caring for the body surface. This includes preening, the cleaning and oiling of feathers with the bill or of hair with the tongue.Aging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.Models, Animal: Non-human animals, selected because of specific characteristics, for use in experimental research, teaching, or testing.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Kisspeptins: Intercellular signaling peptides that were originally characterized by their ability to suppress NEOPLASM METASTASIS. Kisspeptins have since been found to play an important role in the neuroendocrine regulation of REPRODUCTION.Varicellovirus: A genus of the family HERPESVIRIDAE, subfamily ALPHAHERPESVIRINAE. Its species include those causing CHICKENPOX and HERPES ZOSTER in humans (HERPESVIRUS 3, HUMAN), as well as several animal viruses.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Vasectomy: Surgical removal of the ductus deferens, or a portion of it. It is done in association with prostatectomy, or to induce infertility. (Dorland, 28th ed)Plasmodium: A genus of protozoa that comprise the malaria parasites of mammals. Four species infect humans (although occasional infections with primate malarias may occur). These are PLASMODIUM FALCIPARUM; PLASMODIUM MALARIAE; PLASMODIUM OVALE, and PLASMODIUM VIVAX. Species causing infection in vertebrates other than man include: PLASMODIUM BERGHEI; PLASMODIUM CHABAUDI; P. vinckei, and PLASMODIUM YOELII in rodents; P. brasilianum, PLASMODIUM CYNOMOLGI; and PLASMODIUM KNOWLESI in monkeys; and PLASMODIUM GALLINACEUM in chickens.Luteinizing Hormone: A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.Callithrix: A genus of the subfamily CALLITRICHINAE occurring in forests of Brazil and Bolivia and containing seventeen species.Paternity: Establishing the father relationship of a man and a child.Stereotyped Behavior: Relatively invariant mode of behavior elicited or determined by a particular situation; may be verbal, postural, or expressive.Biometry: The use of statistical and mathematical methods to analyze biological observations and phenomena.Spermatogonia: Euploid male germ cells of an early stage of SPERMATOGENESIS, derived from prespermatogonia. With the onset of puberty, spermatogonia at the basement membrane of the seminiferous tubule proliferate by mitotic then meiotic divisions and give rise to the haploid SPERMATOCYTES.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Social Behavior: Any behavior caused by or affecting another individual, usually of the same species.Testosterone: A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.Gonadotropin-Releasing Hormone: A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Epididymis: The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.Association Learning: The principle that items experienced together enter into a connection, so that one tends to reinstate the other.Reaction Time: The time from the onset of a stimulus until a response is observed.Discrimination (Psychology): Differential response to different stimuli.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Hydroxyindoleacetic AcidOrchiectomy: The surgical removal of one or both testicles.Menstrual Cycle: The period from onset of one menstrual bleeding (MENSTRUATION) to the next in an ovulating woman or female primate. The menstrual cycle is regulated by endocrine interactions of the HYPOTHALAMUS; the PITUITARY GLAND; the ovaries; and the genital tract. The menstrual cycle is divided by OVULATION into two phases. Based on the endocrine status of the OVARY, there is a FOLLICULAR PHASE and a LUTEAL PHASE. Based on the response in the ENDOMETRIUM, the menstrual cycle is divided into a proliferative and a secretory phase.Choice Behavior: The act of making a selection among two or more alternatives, usually after a period of deliberation.Seminiferous Tubules: The convoluted tubules in the TESTIS where sperm are produced (SPERMATOGENESIS) and conveyed to the RETE TESTIS. Spermatogenic tubules are composed of developing germ cells and the supporting SERTOLI CELLS.Animals, Newborn: Refers to animals in the period of time just after birth.Hydrocortisone: The main glucocorticoid secreted by the ADRENAL CORTEX. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions.Pattern Recognition, Visual: Mental process to visually perceive a critical number of facts (the pattern), such as characters, shapes, displays, or designs.Visual Cortex: Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.Aggression: Behavior which may be manifested by destructive and attacking action which is verbal or physical, by covert attitudes of hostility or by obstructionism.Cryoprotective Agents: Substances that provide protection against the harmful effects of freezing temperatures.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.
Biomedical Primate Research Centre: The Biomedical Primate Research Centre (BPRC) is Europe's largest primate animal testing research centre. It is a scientific research institute that performs research that contributes to the identification and development of new medicines against deadly diseases.Nephtheis fascicularisPlasmodium osmaniae: Plasmodium osmaniae is a parasite of the genus Plasmodium subgenus Vinckeia.Meta-Hydroxyphenylhydracrylic acidCirculation plan: A circulation plan is a schematic empirical projection/model of how pedestrians and/or vehicles flow through a given area, like, for example, a neighborhood or a Central Business District (CBD). Circulation plans are used by city planners and other officials to manage and monitor traffic and pedestrian patterns in such a way that they might discover how to make future improvements to the system.Anopheles introlatus: Anopheles introlatus (formerly Anopheles balabacensis introlatus) is the main vector for Plasmodium cynomolgi (a simian malaria) in Malaya.Animal euthanasia: Animal euthanasia (euthanasia from ; "good death") is the act of putting an animal to death or allowing it to die as by withholding extreme medical measures. Reasons for euthanasia include incurable (and especially painful) conditions or diseases,2000 Report of the AVMA Panel on Euthanasia lack of resources to continue supporting the animal, or laboratory test procedures.Gestation crate: A gestation crate, also known as a sow stall, is a metal enclosure used in intensive pig farming, in which a female breeding pig (sow) may be kept during pregnancy and for most of her adult life.Wilson G.Capuchin Friary, Crest: The Capuchin Friary in Crest in Drôme, France, is a house of Capuchin friars.The Chimps of Fauna Sanctuary: The Chimps of Fauna Sanctuary: A Canadian Story of Resilience and Recovery is a non-fiction book, written by Canadian writer Andrew Westoll, first published in May 2011 by Harper Collins. In the book, the author chronicles the time he spent volunteering at the Fauna Sanctuary, an animal refuge in Quebec for chimpanzees that had been used for biomedical research.Natural transfer: The natural transfer (hypothesis or theory), in reference to the HIV/AIDS pandemic, states that humans first received HIV by contact with primates, presumably from a fight with a Chimpanzee during hunting or consumption of primate meat, and became contaminated with simian immunodeficiency virus (SIV). According to the 'Hunter Theory', the virus was transmitted from a chimpanzee to a human when a bushmeat hunter was bitten or cut while hunting or butchering an animal.PitheciidaeDipotassium guanylateSynovial osteochondromatosisRectal thermometry: Rectal thermometry is an umbrella term covering the practice, widely used in modern medicine and science, of taking a mammal's temperature by inserting a thermometer into the aforementioned mammal's rectum via the anus. This is generally regarded as the most accurate means of temperature-taking, but some may consider it to be an invasive or humiliating procedure.Tupaia (navigator): Tupaia (also known as Tupaea) (c. 1725 – December, 26 1770) was a Polynesian navigator and arioi (a kind of priest), originally from the island of Ra'iatea in the Pacific Islands group known to Europeans as the Society Islands.Streptanthus breweri: Streptanthus breweri is a species of flowering plant in the mustard family known by the common name Brewer's jewelflower. It is endemic to California, where it can be found in the coastal mountain ranges from the Klamath Mountains south to the San Francisco Bay Area.Biosecurity in the United States: This is a list of biosecurity threats to the United States.Blood–testis barrier: The blood–testis barrier is a physical barrier between the blood vessels and the seminiferous tubules of the animal testes. The name "blood-testis barrier" is misleading in that it is not a blood-organ barrier in a strict sense, but is formed between Sertoli cells of the seminiferous tubule and as such isolates the further developed stages of germ cells from the blood.Grotto of the RedemptionPrint permanence: Print permanence refers to the longevity of printed material, especially photographs, and preservation issues. Over time, the optical density, color balance, lustre, and other qualities of a print will degrade.Charles Ottley Groom NapierVaricellovirus: Varicellovirus (var′i-sel′ō-vi′rŭs) is a genus of viruses belonging to subfamily Alphaherpesvirinae, a member of family Herpesviridae. Humans and mammals serve as natural hosts.Gross pathology: Gross pathology refers to macroscopic manifestations of disease in organs, tissues, and body cavities. The term is commonly used by anatomical pathologists to refer to diagnostically useful findings made during the gross examination portion of surgical specimen processing or an autopsy.Vasectomy: Table 26–1 = Table 3–2 Percentage of women experiencing an unintended pregnancy during the first year of typical use and the first year of perfect use of contraception, and the percentage continuing use at the end of the first year. United States.Plasmodium vinckei: Plasmodium vinckei is a parasite of the genus Plasmodium subgenus Vinckeia.MarmosetMisattributed paternity: Misattributed paternity is the situation when a child’s putative father is not the child's biological father. Overall, the incidence of misattributed paternity ranges from about 1% to 2%, though it may be considerably higher in certain populations.A-scan ultrasound biometry: A-scan ultrasound biometry, commonly referred to as an A-scan, is routine type of diagnostic test used in ophthalmology. The A-scan provides data on the length of the eye, which is a major determinant in common sight disorders.Prenatal nutrition: Nutrition and weight management before and during :pregnancy has a profound effect on the development of infants. This is a rather critical time for healthy fetal development as infants rely heavily on maternal stores and nutrient for optimal growth and health outcome later in life.Coles PhillipsGenetics of social behavior: The genetics of social behavior is an area of research that attempts to address the question of the role that genes play in modulating the neural circuits in the brain which influence social behavior. Model genetic species, such as D.Prenatal testosterone transfer: Prenatal Testosterone Transfer (also known as prenatal androgen transfer or prenatal hormone transfer) refers to the phenomenon in which testosterone synthesized by a developing male fetus transfers to one or more developing fetuses within the womb and influences development. This typically results in the partial masculinization of specific aspects of female behavior, cognition, and morphology, though some studies have found that testosterone transfer can cause an exaggerated masculinization in males.Gonadotropin-releasing hormone analogue: A gonadotropin-releasing hormone analogue (GnRH analogue or analog), also known as a luteinizing hormone releasing hormone agonist (LHRH agonist) or LHRH analogue is a synthetic peptide drug modeled after the human hypothalamic gonadotropin-releasing hormone (GnRH). A GnRH analogue is designed to interact with the GnRH receptor and modify the release of pituitary gonadotropins FSH and LH for therapeutic purposes.Gross examinationEpididymis: The epididymis (; plural: epididymides or ) is a tube that connects a testicle to a vas deferens in the male reproductive system. It is present in all male reptiles, birds, and mammals.Statistical relational learning: Statistical relational learning (SRL) is a subdiscipline of artificial intelligence and machine learning that is concerned with domain models that exhibit both uncertainty (which can be dealt with using statistical methods) and complex, relational structure. Typically, the knowledge representation formalisms developed in SRL use (a subset of) first-order logic to describe relational properties of a domain in a general manner (universal quantification) and draw upon probabilistic graphical models (such as Bayesian networks or Markov networks) to model the uncertainty; some also build upon the methods of inductive logic programming.Temporal analysis of products: Temporal Analysis of Products (TAP), (TAP-2), (TAP-3) is an experimental technique for studyingSeminiferous tubule: Seminiferous tubules are located within the testes, and are the specific location of meiosis, and the subsequent creation of male gametes, namely spermatozoa.Alcohol and cortisol: Recent research has looked into the effects of alcohol on the amount of cortisol that is produced in the human body. Continuous consumption of alcohol over an extended period of time has been shown to raise cortisol levels in the body.Dog aggression: Dog aggression is a term used by dog owners and breeders to describe canine-to-canine antipathy. Aggression itself is usually defined by canine behaviorists as "the intent to do harm".Cryoprotectant: A cryoprotectant is a substance used to protect biological tissue from freezing damage (i.e.HSD2 neurons: HSD2 neurons are a small group of neurons in the brainstem which are uniquely sensitive to the mineralocorticosteroid hormone aldosterone, through expression of HSD11B2. They are located within the caudal medulla oblongata, in the nucleus of the solitary tract (NTS).Branching order of bacterial phyla (Gupta, 2001): There are several models of the Branching order of bacterial phyla, one of these was proposed in 2001 by Gupta based on conserved indels or protein, termed "protein signatures", an alternative approach to molecular phylogeny. Some problematic exceptions and conflicts are present to these conserved indels, however, they are in agreement with several groupings of classes and phyla.
(1/10531) Cerebellar Purkinje cell simple spike discharge encodes movement velocity in primates during visuomotor arm tracking.
Pathophysiological, lesion, and electrophysiological studies suggest that the cerebellar cortex is important for controlling the direction and speed of movement. The relationship of cerebellar Purkinje cell discharge to the control of arm movement parameters, however, remains unclear. The goal of this study was to examine how movement direction and speed and their interaction-velocity-modulate Purkinje cell simple spike discharge in an arm movement task in which direction and speed were independently controlled. The simple spike discharge of 154 Purkinje cells was recorded in two monkeys during the performance of two visuomotor tasks that required the animals to track targets that moved in one of eight directions and at one of four speeds. Single-parameter regression analyses revealed that a large proportion of cells had discharge modulation related to movement direction and speed. Most cells with significant directional tuning, however, were modulated at one speed, and most cells with speed-related discharge were modulated along one direction; this suggested that the patterns of simple spike discharge were not adequately described by single-parameter models. Therefore, a regression surface was fitted to the data, which showed that the discharge could be tuned to specific direction-speed combinations (preferred velocities). The overall variability in simple spike discharge was well described by the surface model, and the velocities corresponding to maximal and minimal discharge rates were distributed uniformly throughout the workspace. Simple spike discharge therefore appears to integrate information about both the direction and speed of arm movements, thereby encoding movement velocity. (+info)
(2/10531) Onset of nucleolar and extranucleolar transcription and expression of fibrillarin in macaque embryos developing in vitro.
Specific aims were to characterize the onset of nucleolar and extranucleolar transcription and expression of the nucleolar protein fibrillarin during preimplantation development in vitro in macaque embryos using autoradiographic and immunocytochemical techniques. Autoradiography was performed on whole embryos cultured with [3H]uridine for assessment of nucleolar (rRNA) and extranucleolar (mRNA) transcription. Expression of fibrillarin was immunocytochemically assessed in whole embryos using a primary antibody against fibrillarin and a fluorescein isothiocyanate-conjugated secondary antibody. Extranucleolar incorporation of [3H]uridine was first detected in 2-cell embryos cultured 6-10 h with [3H]uridine. Culture with alpha-amanitin prevented incorporation of label in 2-cell embryos, and treatment with ribonuclease reduced the signal to background levels, indicating that [3H]uridine was incorporated into mRNA and not rRNA or DNA. Nucleolar incorporation of [3H]uridine was not evident in pronucleate-stage or 2- to 5-cell embryos, but it was detected in one 6-cell embryo and in all 8-cell to blastocyst-stage embryos. Fibrillarin was first expressed in some 6- to 7-cell embryos, but it was consistently expressed in all 8-cell embryos. Fibrillarin was localized to the perimeter of the nucleolar precursor bodies, forming a ring that completely encapsulated these structures. Fibrillarin was not expressed in 8- to 16-cell embryos cultured with alpha-amanitin, indicating that it is transcribed, rather than recruited, at the 8-cell stage. In conclusion, in in vitro-fertilized macaque embryos developing in vitro, extranucleolar synthesis of mRNA is initiated at the 2-cell stage while the onset of nucleolar transcription occurs at the 6- to 8-cell stage, coincident with expression of fibrillarin. (+info)
(3/10531) Association of simian virus 40 with a central nervous system lesion distinct from progressive multifocal leukoencephalopathy in macaques with AIDS.
The primate polyomavirus SV40 is known to cause interstitial nephritis in primary infections and progressive multifocal leukoencephalopathy (PML) upon reactivation of a latent infection in SIV-infected macaques. We now describe a second central nervous system manifestation of SV40: a meningoencephalitis affecting cerebral gray matter, without demyelination, distinct from PML. Meningoencephalitis appears also to be a primary manifestation of SV40 infection and can be seen in conjunction with SV40-induced interstitial nephritis and pneumonitis. The difference in the lesions of meningoencephalitis and PML does not appear to be due to cellular tropism, as both oligodendrocytes and astrocytes are infected in PML and meningoencephalitis, as determined by in situ hybridization or immunohistochemistry for SV40 coupled with immunohistochemistry for cellular determinants. This is further supported by examination of SV40 nucleic acid sequences from the ori-enhancer and large-T-antigen regions, which reveals no tissue-or lesion-specific variation in SV40 sequences. (+info)
(4/10531) Loss of D2 receptor binding with age in rhesus monkeys: importance of correction for differences in striatal size.
The relation between striatal dopamine D2 receptor binding and aging was investigated in rhesus monkeys with PET. Monkeys (n = 18, 39 to 360 months of age) were scanned with 11C-raclopride; binding potential in the striatum was estimated graphically. Because our magnetic resonance imaging analysis revealed a concomitant relation between size of striatum and age, the dynamic positron emission tomography (PET) data were corrected for possible partial volume (PV) artifacts before parameter estimation. The age-related decline in binding potential was 1% per year and was smaller than the apparent effect if the age-related change in size was ignored. This is the first in vivo demonstration of a decline in dopamine receptor binding in nonhuman primates. The rate of decline in binding potential is consistent with in vitro findings in monkeys but smaller than what has been measured previously in humans using PET. Previous PET studies in humans, however, have not corrected for PV error, although a decline in striatal size with age has been demonstrated. The results of this study suggest that PV correction must be applied to PET data to accurately detect small changes in receptor binding that may occur in parallel with structural changes in the brain. (+info)
(5/10531) MST neuronal responses to heading direction during pursuit eye movements.
As you move through the environment, you see a radial pattern of visual motion with a focus of expansion (FOE) that indicates your heading direction. When self-movement is combined with smooth pursuit eye movements, the turning of the eye distorts the retinal image of the FOE but somehow you still can perceive heading. We studied neurons in the medial superior temporal area (MST) of monkey visual cortex, recording responses to FOE stimuli presented during fixation and smooth pursuit eye movements. Almost all neurons showed significant changes in their FOE selective responses during pursuit eye movements. However, the vector average of all the neuronal responses indicated the direction of the FOE during both fixation and pursuit. Furthermore, the amplitude of the net vector increased with increasing FOE eccentricity. We conclude that neuronal population encoding in MST might contribute to pursuit-tolerant heading perception. (+info)
(6/10531) Eye movement deficits following ibotenic acid lesions of the nucleus prepositus hypoglossi in monkeys II. Pursuit, vestibular, and optokinetic responses.
The eyes are moved by a combination of neural commands that code eye velocity and eye position. The eye position signal is supposed to be derived from velocity-coded command signals by mathematical integration via a single oculomotor neural integrator. For horizontal eye movements, the neural integrator is thought to reside in the rostral nucleus prepositus hypoglossi (nph) and project directly to the abducens nuclei. In a previous study, permanent, serial ibotenic acid lesions of the nph in three rhesus macaques compromised the neural integrator for fixation but saccades were not affected. In the present study, to determine further whether the nph is the neural substrate for a single oculomotor neural integrator, the effects of those lesions on smooth pursuit, the vestibulo-ocular reflex (VOR), vestibular nystagmus (VN), and optokinetic nystagmus (OKN) are documented. The lesions were correlated with long-lasting deficits in eye movements, indicated most clearly by the animals' inability to maintain steady gaze in the dark. However, smooth pursuit and sinusoidal VOR in the dark, like the saccades in the previous study, were affected minimally. The gain of horizontal smooth pursuit (eye movement/target movement) decreased slightly (<25%) and phase lead increased slightly for all frequencies (0.3-1.0 Hz, +/-10 degrees target tracking), most noticeably for higher frequencies (0.8-0.7 and approximately 20 degrees for 1.0-Hz tracking). Vertical smooth pursuit was not affected significantly. Surprisingly, horizontal sinusoidal VOR gain and phase also were not affected significantly. Lesions had complex effects on both VN and OKN. The plateau of per- and postrotatory VN was shortened substantially ( approximately 50%), whereas the initial response and the time constant of decay decreased slightly. The initial OKN response also decreased slightly, and the charging phase was prolonged transiently then recovered to below normal levels like the VN time constant. Maximum steady-state, slow eye velocity of OKN decreased progressively by approximately 30% over the course of the lesions. These results support the previous conclusion that the oculomotor neural integrator is not a single neural entity and that the mathematical integrative function for different oculomotor subsystems is most likely distributed among a number of nuclei. They also show that the nph apparently is not involved in integrating smooth pursuit signals and that lesions of the nph can fractionate the VOR and nystagmic responses to adequate stimuli. (+info)
(7/10531) Frontal cognitive impairments and saccadic deficits in low-dose MPTP-treated monkeys.
There is considerable overlap between the cognitive deficits observed in humans with frontal lobe damage and those described in patients with Parkinson's disease. Similar frontal impairments have been found in the 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP) primate model of Parkinsonism. Here we provide quantitative documentation of the cognitive, oculomotor, and skeletomotor dysfunctions of monkeys trained on a frontal task and treated with low-doses (LD) of MPTP. Two rhesus monkeys were trained to perform a spatial delayed-response task with frequent alternations between two behavioral modes (GO and NO-GO). After control recordings, the monkeys were treated with one placebo and successive LD MPTP courses. Monkey C developed motor Parkinsonian signs after a fourth course of medium-dose (MD) MPTP and later was treated with combined dopaminergic therapy (CDoT). There were no gross motor changes after the LD MPTP courses, and the average movement time (MT) did not increase. However, reaction time (RT) increased significantly. Both RT and MT were further increased in the symptomatic state, under CDoT. Self-initiated saccades became hypometric after LD MPTP treatments and their frequency decreased. Visually triggered saccades were affected to a lesser extent by the LD MPTP treatments. All saccadic parameters declined further in the symptomatic state and improved partially during CDoT. The number of GO mode (no-response, location, and early release) errors increased after MPTP treatment. The monkeys made more perseverative errors while switching from the GO to the NO-GO mode. Saccadic eye movement patterns suggest that frontal deficits were involved in most observed errors. CDoT had a differential effect on the behavioral errors. It decreased omission errors but did not improve location errors or perseverative errors. Tyrosine hydroxylase immunohistochemistry showed moderate ( approximately 70-80%) reduction in the number of dopaminergic neurons in the substantia nigra pars compacta after MPTP treatment. These results show that cognitive and motor disorders can be dissociated in the LD MPTP model and that cognitive and oculomotor impairments develop before the onset of skeletal motor symptoms. The behavioral and saccadic deficits probably result from the marked reduction of dopaminergic neurons in the midbrain. We suggest that these behavioral changes result from modified neuronal activity in the frontal cortex. (+info)
(8/10531) Visuomotor processing as reflected in the directional discharge of premotor and primary motor cortex neurons.
Premotor and primary motor cortical neuronal firing was studied in two monkeys during an instructed delay, pursuit tracking task. The task included a premovement "cue period," during which the target was presented at the periphery of the workspace and moved to the center of the workspace along one of eight directions at one of four constant speeds. The "track period" consisted of a visually guided, error-constrained arm movement during which the animal tracked the target as it moved from the central start box along a line to the opposite periphery of the workspace. Behaviorally, the animals tracked the required directions and speeds with highly constrained trajectories. The eye movements consisted of saccades to the target at the onset of the cue period, followed by smooth pursuit intermingled with saccades throughout the cue and track periods. Initially, an analysis of variance (ANOVA) was used to test for direction and period effects in the firing. Subsequently, a linear regression analysis was used to fit the average firing from the cue and track periods to a cosine model. Directional tuning as determined by a significant fit to the cosine model was a prominent feature of the discharge during both the cue and track periods. However, the directional tuning of the firing of a single cell was not always constant across the cue and track periods. Approximately one-half of the neurons had differences in their preferred directions (PDs) of >45 degrees between cue and track periods. The PD in the cue or track period was not dependent on the target speed. A second linear regression analysis based on calculation of the preferred direction in 20-ms bins (i.e., the PD trajectory) was used to examine on a finer time scale the temporal evolution of this change in directional tuning. The PD trajectories in the cue period were not straight but instead rotated over the workspace to align with the track period PD. Both clockwise and counterclockwise rotations occurred. The PD trajectories were relatively straight during most of the track period. The rotation and eventual convergence of the PD trajectories in the cue period to the preferred direction of the track period may reflect the transformation of visual information into motor commands. The widely dispersed PD trajectories in the cue period would allow targets to be detected over a wide spatial aperture. The convergence of the PD trajectories occurring at the cue-track transition may serve as a "Go" signal to move that was not explicitly supplied by the paradigm. Furthermore, the rotation and convergence of the PD trajectories may provide a mechanism for nonstandard mapping. Standard mapping refers to a sensorimotor transformation in which the stimulus is the object of the reach. Nonstandard mapping is the mapping of an arbitrary stimulus into an arbitrary movement. The shifts in the PD may allow relevant visual information from any direction to be transformed into an appropriate movement direction, providing a neural substrate for nonstandard stimulus-response mappings. (+info)