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At least 253 records · Page 14Linked to original sources
PubMed1986

Effects on the behavior of infant common marmosets (Callithrix jacchus) of separation from caregivers and of drug-induced reduction in caregiver responsiveness.

The effects of separating 4-week-old twin marmosets for 8 days from their families are compared with the effects of leaving 4-week-old infants with their families, but reducing the responsiveness of their caregivers for 8 days by administration of the tranquilizer fluphenazine decanoate. Both treatments reduce infant mobility, abolish play, and increase the time that infants spend with each other. During the period after the termination of the treatment, both treatment groups continue to play and move less than controls, and try to climb onto the mothers more frequently. These results are consistent with the hypothesis that the principal factor precipitating disturbed behaviors in infant monkeys subjected to long-term separation is disruption of the infant-caregiver relationship rather than the separation itself. Some post-treatment differences occur between separated and tranquilized groups. Notably, reunion after separation appears to involve a marked readjustment of the behavior of all family members to the return of the infants, whereas withdrawal of the tranquilizer does not.

Animals↗
PubMed1989

The diagnostic usefulness of isocitrate dehydrogenase (ICDH) in the marmoset (Callithrix jacchus).

Marmosets were given either a hepatotoxin, carbon tetrachloride, orally or an i.m. injection of a mytoxin, chlorpromazine. Although muscle damage alone caused small increases in the plasma levels of lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase and isocitrate dehydrogenase (ICDH), only the isoenzyme analysis of ICDH can differentiate definitely between liver and muscle damage. Only very severe muscle damage can increase the plasma concentration of this enzyme but, in this case, the elevation of plasma creatinine kinase levels helps differentiation. It is recommended that the elevation of ICDH is the most specific indicator of hepatic damage in the marmoset.

Alanine Transaminase↗
PubMed1993

The neuropathology of trimethyltin in the marmoset (Callithrix jacchus) hippocampal formation.

The effects of single and repeated doses of trimethyltin (TMT) treatment on the central nervous system (CNS) of the marmoset were investigated. For the acute-dose experiment adult animals were administered 3 mg/kg of TMT chloride (ip) and were then observed for changes in behavior. Within 24 hr postinjection all animals developed tremors, ataxia, and unresponsiveness. Half of the animals had severe clinical deterioration and died at 2 to 3 days following treatment. Surviving marmosets were sacrificed and the brain was subsequently perfusion-fixed for light microscopic examination. Neuronal degeneration was observed in many cells of the Ammon's horn and fascia dentata of the hippocampus. For the chronic-dose experiment, adult marmosets received (ip) weekly doses of 0.75 mg/kg of TMT chloride for 24 weeks. No evident clinical signs or behavioral changes were observed in any of the treated animals. Histological examination revealed neuropathological changes comparatively similar but less severe than those observed in the acute-treated animals. The differences in toxicity effects between acute and chronic TMT administration are compared and discussed.

Animals↗
PubMed1993

Effects of testosterone propionate upon the sexual and aggressive behavior of adult male marmosets (Callithrix jacchus) castrated as neonates.

In New World monkeys of the family Callitrichidae (marmosets and tamarins), females frequently give birth to dizygotic twins. Twins share a placental circulation throughout fetal development and are hemopoietic chimeras. Despite this, there is no masculinization (freemartinism) in females which develop next to a male co-twin. It has been suggested that the organizing effects of testicular androgen upon sexual differentiation of the brain occur mainly during early postnatal development in male callitrichids, rather than in utero. However, this report demonstrates activation of masculine copulatory behavior by testosterone propionate (TP) administered to adult male marmosets (N = 8) which were castrated in infancy (between Days 1-7). Effects of neonatal castration upon aggressive behavior during pair tests with females (high frequencies of aggression) and intact adult males (low frequencies of aggression) were also reversed by TP treatment in adulthood. While early postnatal androgen secretion plays an important role in behavioral development in marmosets, it appears that a substantial degree of neural sexual differentiation occurs in utero in males of this callitrichid species.

Aggression↗
PubMed1995

Quantitative receptor autoradiography of eight different transmitter-binding sites in the hippocampus of the common marmoset, Callithrix jacchus.

The regional and laminar distributions of eight different transmitter-binding sites were measured in the marmoset hippocampus by means of quantitative in vitro receptor autoradiography. Receptors for 5-HT1, L-glutamate, N-methyl-D-aspartate (NMDA) and GABAA were similarly distributed. The highest concentrations of these receptors were found in the pyramidal layer of CA1 and the molecular layer of the dentate gyrus. The 5-HT2 receptors showed the highest concentrations in the oriens layer of CA2. The highest concentrations of muscarinic M1 receptors were seen in the pyramidal layer of CA1. Muscarinic M2 receptors were most densely concentrated in the pyramidal layers of CA1, CA2 and CA3. The noradrenergic alpha 1 receptors were most densely packed in the radiatum-lacunosum-molecular layer of CA2 and the molecular layer of the dentate gyrus. Statistically significant co-distributions of serotoninergic, glutamatergic and GABAergic receptors point to possible interactions between these receptor systems in the same hippocampal regions and layers. Comparisons of marmoset distribution patterns for GABAA, NMDA, L-glutamate and 5-HT1 receptors with those in human hippocampi and those of other primates showed similarities between them. Clear differences in the patterns of alpha 1, M1, M2 and 5-HT2 receptors could be seen between marmoset and human hippocampi, indicating a high degree of species specificity in a presumably "conservative" brain region. More similarities, however, could be found between marmoset and human hippocampi than between those of rat and human brains, especially in relation to 5-HT1 and GABAA receptors and L-glutamate-binding sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Intercellular communication between cultured granulosa cells of the marmoset (Callithrix jacchus).

The influence of follicle-stimulating hormone, forskolin, insulin-like growth factor type I, epidermal growth factor, and 12-tetradecanoyl-phorbol-13-acetate on marmoset granulosa cell communication via gap junctions was investigated by morphological means and microinjection of carboxyfluorescein. Gap junctions between neighbouring granulosa cells were present in all groups. The number, but not length, of gap junctions between marmoset granulosa cells increased when the cells had been treated with follicle-stimulating hormone, insulin-like growth factor type I, and follicle-stimulating hormone plus insulin-like growth factor type I. No effect on gap junctions was seen, after exposure of the cells to the other three substances. Carboxyfluorescein and counting of the surrounding labelled cells showed that supplementation with follicle-stimulating hormone, forskolin, insulin-like growth factor type I and epidermal growth factor from the beginning of cultivation led to an increase in stained cells after 48 h. When treatment was started in 48 h cultures the substances reached their maximal activity within 30 min (forskolin and epidermal growth factor) or 3 h (follicle-stimulating hormone and insulin-like growth factor type I). Spreading of the fluorescent dye was inhibited when the medium was supplemented with 12-tetradecanoyl-phorbol-13-acetate. This effect was maximal after 30 min. Additive effects regarding the coupling of the cells were seen by combining of epidermal growth factor with follicle-stimulating hormone, but not with insulin-like growth factor type I or forskolin plus follicle-stimulating hormone.

Animals↗
PubMed1985

A conveyor belt task for assessing visuo-motor coordination in the marmoset (Callithrix jacchus): effects of diazepam, chlorpromazine, pentobarbital and d-amphetamine.

A conveyor belt task for assessing visuo-motor coordination in the marmoset is described. Animals are motivated by apple, a preferred food, under a state of minimal food deprivation. The apparatus used was designed to test animals within their home cages and not restrained in any way, thus avoiding possible confounding factors associated with restraint stress. Stable baseline levels of performance were reached by all animals in a median of 24 sessions. Performance was shown to be differentially sensitive to the effects of four psychoactive drugs. Moderate doses of diazepam, chlorpromazine and pentobarbital disrupted visuo-motor coordination in a dose-related manner. The possibility that disruption of performance observed at higher doses may have resulted from non-specific actions of these drugs such as decreases in feeding motivation were not supported by results from ancillary experiments. Changes in performance characteristic of high dose effects were similar in nature to changes observed when the degree of task difficulty was increased. Doses of d-amphetamine up to and including those reported to produce signs of stereotypy failed to influence performance. The potential of the conveyor belt task for measuring visuo-motor coordination in both primate and rodent species is discussed.

Animals↗
PubMed1983

Investigations into the induction of chronic experimental arthritis in the common marmoset (Callithrix jacchus).

In an attempt to produce a superior model of rheumatoid arthritis, experiments have been performed to investigate the ease of induction of experimental arthritis in marmosets by immunological means. Marmosets were sensitised with the following combinations of antigen and adjuvant: ovalbumin in Freund's complete adjuvant (FCA), ovalbumin in FCA + Bordetella pertussis, methylated-BSA in FCA + B. pertussis or human fibrin in FCA + B. pertussis, and subsequently injected with the corresponding antigen in saline into one knee joint. Animals receiving ovalbumin, with or without B. pertussis, produced only a weak transient monoarticular synovitis. Animals receiving Met-BSA + B. pertussis produced a chronic synovitis but only mild erosive changes were apparent even 21 weeks after intraarticular injection. Animals receiving human fibrin produced a transient monoarticular synovitis of moderate intensity. These results indicate that the marmoset offers no obvious advantages over the rabbit for the induction of experimental rheumatoid arthritis.

Animals↗
PubMed1997

The expression of sf-1/Ad4BP is related to the process of luteinization in the marmoset (Callithrix jacchus) ovary.

Expression of the nuclear receptor, steroidogenic factor-1 (SF-1/Ad4BP), was studied in a primate (marmoset) ovary using immunohistochemical, RT-PCR, and immunoblot techniques. The periovulatory phase was compared with the luteal phase. With PCR we found a marmoset homolog of SF-1/Ad4BP to be expressed in ovarian and other steroidogenic tissues. Characteristically, the periovulatory ovaries consisted of growing (non-luteinized) small follicles together with large luteinizing follicles and many corpora lutea accessoria (Clas), which had developed from atretic large follicles. During the luteal phase, true corpora lutea (Cls) were additionally found. In general, we found that small follicles were devoid of any immunoreactivity of SF-1/Ad4BP. In large follicles, the luteinizing theca and granulosa cells express SF-1/Ad4BP. All luteal cells of Clas showed a nuclear staining in both ovary types. In Cls, only a few luteal cells were positive. Large follicles of different sizes showed no differences in expression level, as evidenced by immunoblot analysis. Our results indicate that SF-1/ Ad4BP participates in the activation of genc transcription during the onset of luteinization and that Clas are essential for ovarian luteal function.

Animals↗
PubMed1986

Anteromedial hypothalamic lesions block proceptivity but not receptivity in the female common marmoset (Callithrix jacchus).

The sexual behavior of 8, estradiol-treated, ovariectomized common marmosets was recorded prior to and after bilateral radiofrequency lesions of the hypothalamus. Lesions of the anterior hypothalamus, which extended to varying degrees into the medial hypothalamus, virtually abolished proceptive tongue-flicking and staring displays. Tongue-flicking during copulation also decreased, but the females did not show any significant increase in the number of mounts which they refused or terminated with the exception of one animal which had received more extensive damage to the medial hypothalamus. Significant increases in the frequencies of allogrooming and grooming invitations also occurred after the females had been lesioned. Sexual behavior was not significantly altered in 3 females which received sham lesions. These results provide the first direct evidence for a neuroanatomical distinction between hypothalamic mechanisms which regulate proceptivity and receptivity in primates.

Animals↗
PubMed1987

A new heterotopic callosal projection of primary visual cortex in the monkey, Callithrix jacchus.

A callosal projection of area 17 upon the dorsomedial visual area in the marmoset monkey was demonstrated by means of retrograde transport of neuronal tracers. The projection was restricted to those regions representing the vertical meridian in the two areas. This finding, and the data of other authors, indicate that the monkey area 17 projects transcallosally onto homotopic and several heterotopic targets.

Animals↗
PubMed1987

Behavioural consequences of the infusion of dopamine into the nucleus accumbens of the common marmoset (Callithrix jacchus).

Marmosets, shown to have comparable levels of spontaneous locomotor activity, assessed in cages equipped with infra-red photocell units, could be separated into "high", "moderate" and "low activity" responders on the basis of their locomotor hyperactivity response to peripherally administered (-)N-n-propylnorapomorphine [(-)NPA]. Animals selected as "low" and "high activity" responders to (-)NPA were subjected to chronic infusion of dopamine, or its solvent, bilaterally into the nucleus accumbens for 13 days through Alzet osmotic minipumps. Both "low" and "high activity" responders exhibited an increased locomotor activity which peaked on days 6-7 of the infusion. This hyperactivity, caused by infusion of dopamine was antagonised by small doses of sulpiride and fluphenazine. After the infusion, the level of spontaneous locomotor activity of the marmosets was unchanged from pre-infusion values. However, 2-3 weeks after discontinuing the infusion, the animals initially classified as "low activity" responders showed markedly enhanced activity when challenged with (-)NPA, and conversely, animals initially classified as "high activity" responders showed a reduced responsiveness to (-)NPA. It is concluded that the consequences of a persistent increase in the activity of dopamine in the nucleus accumbens of the brain of the marmoset are to (a) enhance locomotor activity during infusion and (b) after discontinuing infusion, to modify the locomotor responsiveness to challenge with a dopamine agonist, with the direction of the change dependent on the initial basal locomotor responsiveness to (-)NPA.

Animals↗
PubMed1983

The effect of the ovarian cycle on the sexual behaviour of the common marmoset (Callithrix jacchus).

The sexual behaviour of 7 pairs of marmosets was observed during 30 minute tests for 44-68 days and blood samples were collected from females for measurement of plasma progesterone, testosterone and oestrone. Copulations occurred throughout the ovarian cycle of 24-30 days. Females used a "tongue-flicking" display both as an invitational behaviour (proceptive tongue-flicks) and during copulation (receptive tongue-flicks) most frequently during the peri-ovulatory period. Frequencies of proceptivity were correlated positively with high mean levels of testosterone and oestrone during the cycle and with a short follicular phase. Males showed significant increases in tongue-flicks, mounts and ejaculations during the peri-ovulatory phase, together with a shortened post-ejaculatory interval and increased duration of penile erection after ejaculation. A retrospective analysis showed that these changes in the males' behaviour occurred only during tests where females were proceptive and not during other tests in the peri-ovulatory period. Females refused significantly more of the males' mounting attempts during the luteal phase and a corresponding reduction in mount frequency occurred at this time. Grooming, scent-marking, olfactory inspections and some other behaviours did not alter significantly in either sex during the ovarian cycle.

Animals↗
PubMed1985

Effects of oestradiol 17B, progesterone and testosterone upon proceptivity and receptivity in ovariectomized common marmosets (Callithrix jacchus).

The sexual behaviour of eight pairs of marmosets was observed during blocks of 30 minute tests after the ovariectomized female partners were treated with physiological doses of testosterone, oestradiol and progesterone. The effects of an intra-vaginal progesterone treatment were also investigated. Pre-ovulatory levels of oestradiol significantly increased the females' proceptive and receptive tongue-flicking displays and reduced the percentage of mounts refused. Mid-luteal levels of progesterone, by comparison, virtually abolished proceptive and receptive tongue-flicking and significantly increased mount refusals. Testosterone treatment was without effect. Vaginal application of progesterone unlike subcutaneous implantation of the hormone did not significantly alter the females' sexual behaviour. These results indicate that central actions of oestradiol and progesterone upon proceptivity and receptivity may occur in this primate, although further research using intra-cranial implants of these steroids is required to test this hypothesis.

Animals↗
PubMed1986

Genital sensory feedback and sexual behaviour in male and female marmosets (Callithrix jacchus).

Local anaesthesia (using lidocaine) of the penis, or of the vagina and cervix caused marked changes in the sexual behaviour of marmosets. Penile desensitization did not affect sexual arousal or erectile capacity. However, intromission latencies increased and 7 out of 10 males failed to intromit during some post-lidocaine tests. Females failed to show several behavioural patterns which normally occur during intromission (shrugging body movements, head turning and opening the mouth) or exhibited them at reduced frequencies after intra-vaginal application of lidocaine. The tendency of females to terminate mounts after ejaculation had occurred was also reduced with resultant increases in intromission duration in all cases. Desensitization of the females' external genitalia had no effect upon sexual behaviour. Co-ordination of copulatory behaviour in this primate species depends, in part, upon afferent stimuli from the penis and from the vagina or cervix.

Animals↗