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At least 325 records · Page 18Linked to original sources
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↗
PubMed1987

Post-partum changes in hormones and sexual behaviour in captive groups of marmosets (Callithrix jacchus).

Video-tape recordings were made of behavioural interactions in eight family groups of marmosets for 24-30 days after parturition. Blood samples were collected from females for measurement of plasma luteinizing hormone (LH) and progesterone. A pre-ovulatory LH surge occurred in six females between days 10-18 (mean +/- sem, 13.8 +/- 1.3 days). In these groups, sexual interactions increased in frequency during the post-partum period and males began to initiate mounts on days 1, 2, 2, 6, 8 and 10 respectively. Mount and ejaculation frequencies increased significantly during the peri-ovulatory phase as compared to the pre-ovulatory phase and females were more proceptive and receptive than in the early post-partum period. Peri-ovulatory increases in sexual activity were more pronounced in 3 groups in which females had failed to conceive. In the remaining 3 groups, sexual interactions tended to continue at higher levels into the post-ovulatory phase when the females were pregnant. In captive marmoset groups, copulatory behaviour during the post-partum period is stimulated by changes in non-behavioural cues from the female (increased sexual attractiveness to the male) as well as by changes in her behaviour (proceptivity, receptivity) which vary in importance between individuals.

Aggression↗
PubMed1987

Effects of adrenalectomy upon proceptivity, receptivity and sexual attractiveness in ovariectomized marmosets (Callithrix jacchus).

The sexual behaviour of seven pairs of marmosets was observed during blocks of 30 minute tests before and after the ovariectomized partners were bilaterally adrenalectomized. Adrenalectomized females were maintained by intramuscular injections of deoxycorticosterone pivalate (DC) and hydrocortisone hemisuccinate (HC). Twice daily injections of HC were required to maintain the high levels of plasma cortisol typical of marmosets and some other New World primates. Adrenalectomy had no significant effects upon proceptivity, receptivity or female sexual attractiveness. Increasing the replacement dose of DC had no effects upon sexual behaviour. Oestradiol treatment caused a marked increase in proceptivity (tongue-flicking, staring and immobile displays) and in receptive tongue-flicking behaviour. Males ejaculated more frequently during tests with oestradiol-treated partners. These results indicate that during "pair tests" adrenocortical sex steroids are not essential for maintenance of sexual behaviour in female marmosets and that activation of proceptivity by oestradiol 17 beta can occur in the absence of the adrenal glands.

Adrenalectomy↗
PubMed1991

Penile spines affect copulatory behaviour in a primate (Callithrix jacchus).

Androgen-dependent, keratinized "spines" occur on the glans penis in many rodents, primates and other mammals. Since penile spines overlie dermal tactile receptors, they may play a role in copulatory behaviour. An experiment was conducted to test this hypothesis. Sixteen sexually experienced adult male marmosets were paired with ovariectomized females before, and after, removal of penile spines (using thioglycollate cream applied to the glans under anaesthesia) or a sham operation. Spine removal resulted in an increased duration of preintromission pelvic thrusting (mean +/- s.e.m. from 6.87 +/- 1.09 to 14.94 +/- 3.32 s, p = 0.05) and of intromitted thrusting (from 1.73 +/- 0.11 to 2.0 +/- 0.11 s, p less than 0.05). Three males exhibited partial intromissions during some postspinectomy tests, an effect which had not been observed prior to the operation. Sham operations had no behavioural effects. Results indicate that penile spines play a significant (but not indispensible) role in sensory feedback during copulation in this primate species.

Androgens↗
PubMed1993

Sexual and aggressive behaviour of adult male marmosets (Callithrix jacchus) castrated neonatally, prepubertally, or in adulthood.

During early postnatal development, males of some primate species exhibit higher levels of plasma testosterone than females. The possible significance of this for behavioural development was examined in male marmosets castrated neonatally (NC), prepubertally (PC), or in adulthood (AC) and reared in their natal groups. Age-matched intact (AI) adult males served as controls. All males were removed from their natal groups as adults for pair testing with unfamiliar conspecific males and females. NC males did not mount, but were frequently aggressive during tests with females. NC males also elicited aggression from females but rarely from intact males. PC and AC males attempted copulation during the majority of tests with females; less aggression occurred but more so in tests with PC males than between females and AC males. Aggression between PC or AC males and intact males was much more frequent than when NC males met intacts in paired encounters. Results show that secretion of testicular hormones during infancy in male marmosets has important effects upon the development of sexual and aggressive behaviour. Castration in infancy has measurably different effects upon behavioural development than castration performed later in life (prepubertally or in adulthood).

Aggression↗
PubMed1992

The relationship between cone pigments and behavioural sensitivity in a New World monkey (Callithrix jacchus jacchus).

Microspectrophotometric measurements of visual pigments and behavioural measurements of spectral sensitivity are reported for individual marmosets from 3 family groups. The sex differences and polymorphism that characterise the long-wave cone pigments in this species are well reflected by variations in the behavioural sensitivities. With one exception, the pattern of inheritance is compatible with a genetic model in which the long-wave pigment is specified by a single polymorphic locus on the X-chromosome. Measurements are also reported for the spectral absorbance of the marmoset lens, and these are used to reconstruct short-wave behavioural sensitivity from the microspectrophotometric measurements of the short-wave cones.

Animals↗
PubMed1989

Termination of pregnancy in common marmosets (Callithrix jacchus) following administration of antiserum to chicken riboflavin carrier protein.

The presence of protein(s) which is immunologically and functionally similar to the well characterised avian riboflavin carrier protein has been demonstrated in female common marmosets during pregnancy. The protein(s) that interacts with [14C]riboflavin has an immunological homology to chicken riboflavin carrier protein. The termination of pregnancy in four out of six marmosets following administration of antiserum to chicken riboflavin carrier protein supports the hypothesis that vitamin carrier protein ensures an uninterrupted supply of the vitamin to the growing embryo and that immunoneutralization of maternal riboflavin carrier protein leads to fetal death and termination of pregnancy.

Animals↗
PubMed1989

The distribution of glial fibrillary acidic protein and vimentin in postnatal marmoset (Callithrix jacchus) brain.

Antisera to glial fibrillary acidic protein (GFAP) and vimentin were used to elucidate the distribution of these intermediate filament proteins in postnatal marmoset brains of various ages. The ependyma of the lateral ventricles was unique in being equally immunoreactive for both GFAP and vimentin at all ages. Vimentin alone was consistently demonstrated in endothelial and leptomeningeal cells at all ages. In neonates, vimentin immunoreactivity greatly exceeded that of GFAP and was located primarily in radial glia in the subependymal plate of the anterior cerebrum. Their vimentin-positive processes formed thick fascicles in the corpus callosum but separated into fine fibres on entering the cortex. GFAP immunoreactivity in these cells and processes was very limited. With age, GFAP-positive cells increased in number and displayed the typical stellate appearance of astroglia. The vimentin-positive radial glial population decreased considerably during this period and by 6 months had virtually disappeared. The GFAP reaction in adult brain was even more widespread, largely due to the increased number of positive astrocytes in the white matter. Vimentin immunoreactivity in the adult was greatly diminished and positive radial glia were not detectable. A major change in intermediate filament protein expression, therefore, occurs in the early postnatal period and probably reflects phases in the differentiation of radial glial precursors into astrocytes.

Animals↗
PubMed1990

Cell proliferation in the subependymal layer of the postnatal marmoset, Callithrix jacchus.

Cells of the subependymal layer (SEL) have been shown to be capable of continued postnatal cell division throughout life in rodents. To determine if the primate brain behaves similarly, proliferative activity in the SEL of the marmoset has been investigated by tritiated thymidine autoradiography and bromodeoxyuridine immunocytochemistry. Both methods revealed the presence of DNA-synthesizing cells at all postnatal ages studied. The labelling index (LI), low at birth, reached a peak of almost 4% at one month but decreased gradually thereafter. In animals older than two years the LI was extremely low and labelled cells were rarely seen anywhere in the brain. The cell density of the SEL, in contrast to the low LI, was highest in neonates and decreased linearly with increasing age. Bromodeoxyuridine immunoreactivity revealed the distribution of proliferating cells in the SEL and neighbouring regions. Such cells were most abundant around the anterior lateral ventricle where the SEL was most evident. Proliferating cells were numerous in neonates, though not adjacent to the ependyma where counts for the LI were made, and were mainly located dorsally and ventrally at the junctions of the corpus callosum and caudate nucleus.

Aging↗
PubMed1986

Effects of variable linoleate intake on aortic PGI2-like activity and fatty acid composition: difference between rat and marmoset (Callithrix jacchus).

Two animal species, the laboratory rat and a non-human primate (the common marmoset) were compared with respect to the influence of dietary lipid supplementation on both fatty acid composition and prostanoid synthetic capacity of aorta. Standard chow (REF. diet) was supplemented (12% w/w) with either sheep fat (SF) or sunflower seed oil (SSO). Differences were apparent in the aortic phospholipid fatty acids from both animal models, as a result of the diet, although the type and the extent of changes displayed a considerable species variation. For example, after the SSO diet, the proportion of linoleic acid in rat aorta displayed only a modest increase whilst in marmosets it was doubled. No change was apparent in the proportion of arachidonic acid in rats, whereas the marmosets showed a reduction (P less than 0.05) with both lipid supplements. Rats fed the SF diet showed a considerable increase in aortic PGI2-like activity compared to REF. And SSO supplemented groups. In contrast, no dietary induced changes were observed in the aorta from marmosets despite compositional changes. The results indicate no direct association between the synthesis of PGI2-like activity and membrane lipids and demonstrate the need for careful selection of the proper animal model, particularly in nutritionally orientated experiments.

Animals↗
PubMedDate not supplied

Dietary lipids and adipose tissue fatty acids in the marmoset monkey (Callithrix jacchus).

The fatty acid composition of marmoset monkey perirenal fat was examined after long-term feeding of different lipid supplemented diets. Saturated fatty acid supplementation significantly reduced linoleic acid; n-6 polyunsaturated fatty acid (PUFA) supplementation decreased oleic acid but did not reduce the saturated fatty acid content of perirenal fat. Dietary supplementation with fish oil also reduced the level of linoleic acid but increased the level of palmitic acid as well as that of the long-chain n-3 PUFAs. Perirenal fat levels of linoleic acid and docosahexaenoic acid are reliable measures of n-6 and n-3 PUFA intake respectively, but the levels of saturated fatty acids palmitic and stearic do not accurately reflect the marmosets dietary intake.

Adipose Tissue↗