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At least 19 recordsLinked to original sources
PubMed1976

The thermoreculatory responses of the galago (Galago crassicaudatus), the baboon (Papio cynocephalus) and the chimpanzee (Pan stayrus) to heat stress.

1. The thermoregulatory response of the galago, the baboon and the chimpanzee were studied on exposure to dry bulb temperatures of up to 40 degrees C in a temperature controlled room. 2. Heat exposure caused an elevation in the respiratory frequency of all three species. The increase in the galago was significantly greater than that in the baboon and the chimpanzee. 3. Heat exposure also caused an increase in the cutaneous moisture loss of the baboon and the chimpanzee but not in the galago. 4. Rectal temperatures always rose on heat exposure but the animals never become hypethermic. 5. Sweat gland activity in the baboon and the chimpanzee was stimulated by the administration of acetylcholine and was blocked by the administration of atropine. Sympathetic and parasympathetic drugs had no stimulatory effect on the sueat glands of the galago. 6. Local, infra-red heating of the skin of the galago and the baboon did not stimulate any sweat gland activity. 7. The sweat glands in the galago and the baboon were found to be epitrichial. 8. These findings are discussed in relation to the habitat of each species. They are also compared to thermoregulation in other primate species, especially in relation to the unique nature of thermoregulation in man.

Acetylcholine↗
PubMed1978

Effects of ovariectomy and estradiol replacement therapy upon the sexual and aggressive behavior of the greater galago (Galago crassicaudatus crassicaudatus).

The effects of ovariectomy and estradiol treatment upon sexual and aggressive behavior were studied in a prosimian primate, the greater galago. Ovariectomized galagos were sexually unreceptive and frequently aggressive, but retained their sexual attractiveness to males. When females were treated with estradiol monobenzoate, however, their aggression and refusals of males' mounting attempts decreased markedly. Although males mounted these females, they usually failed to copulate, possibly because the females did not perform certain postural adjustments which assist males to intromit. Estradiol benzoate alone, even in large does, does not fully restore patterns of mating behavior in ovariectomized female greater galagos. These observations on a prosimian primate are in striking contrast to the results of similar work on Old World monkeys and chimpanzees.

Aggression↗
PubMed1976

Effects of testosterone on the sternal cutaneous glands and genitalia of the male greater galago (Galago crassicaudatus crassicaudatus).

Adult male and some female Galago crassicaudatus have a sparsely haired sternal gland which is used in scent marking displays. In both sexes, the skin in the sternal area contains many large sebaceous and apocrine glands. The sebaceous glands are largest in males and are dependent upon testicular androgens. Spines on the glans penis are also androgen dependent; their possible behavioural functions are discussed.

Animals↗
PubMed1979

Mandibular function in Galago crassicaudatus and Macaca fascicularis: an in vivo approach to stress analysis of the mandible.

Single-element and/or rosette strain gages were bonded to mandibular cortical bone in Galago crassicaudatus and Macaca fascicularis. Five galago and eleven macaque bone strain experiments were performed and analyzed. In vivo bone strain was recorded from the lateral surface of the mandibular corpus below the postcanine tooth row during transducer biting and during mastication and ingestion of food objects. In macaques and galagos, the mandibular corpus on the balancing side is primarily bent in the sagittal plane during mastication and is both twisted about its long axis and bent in the sagittal plane during transducer biting. On the working side, it is primarily twisted about its long axis and directly sheared perpendicular to its long axis, and portions of it are bent in the sagittal plane during mastication and molar transducer biting. In macaques, the mandibular corpus on each side is primarily bent in the sagittal plane and twisted during incisal transducer biting and ingestion of food objects, and it is transversely bent and slightly twisted during jaw opening. Since galagos usually refused to bite the transducer or food objects with their incisors, an adequate characterization of mandibular stress patterns during these behaviors was not possible. In galagos the mandibular corpus experiences very little transverse bending stress during jaw opening, perhaps in part due to its unfused mandibular symphysis. Marked differences in the patterns of mandibular bone strain were present between galagos and macaques during the masticatory power stroke and during transducer biting. Galagos consistently had much more strain on the working side of the mandibular corpus than on the balancing side. These experiments support the hypothesis that galagos, in contrast to macaques, employ a larger amount of working-side muscle force relative to the balancing-side muscle force during unilateral biting and mastication, and that the fused mandibular symphysis is an adaption to use a maximal amount of balancing-side muscle force during unilateral biting and mastication. These experiments also demonstrate the effects that rosette position, bite force magnitudes, and types of food eaten have on recorded mandibular strain patterns.

Animals↗
PubMed1977

In vivo bone strain in the mandible of Galago crassicaudatus.

Single element foil strain gages were bonded to mandibular cortical bone in eight specimens of Galago crassicaudatus. The gage was bonded below the Pm4 or M2 adjacent to the lower border of the mandible. The bonded strain gage was connected to form one arm of a Wheatstone bridge. Following recovery from the general anesthetic, the restrained Galago bit either a piece of wood, a food object, or a bite force transducer. During these biting episodes, mandibular bone strain deformed the strain gage and the resulting change in electrical resistance of the gage caused voltage changes across the Wheatstone bridge. These changes, directly proportional to the amount of bone strain along the gage site, were recovered by a strip chart recorder. Bone strain was measured on both the working and balancing sides of the jaws. Maximum values of bone strain and bite force were 435 microstrain (compression) and 8.2 kilograms respectively. During bending of the mandible, the correlation between bone strain (tension or compression) and bite force ranged from -0.893 (tension) to 0.997 (compression). The experiments reported here demonstrate that only a small percentage of the Galago bite force is due to balancing side muscle force during isometric unilateral molar biting. In addition, these experiments demonstrate that the Galago mandible is bent in a predictable manner during biting. The amount of apparent mandibular bone strain is dependent on (1) the magnitude of the bite force and (2) the position of the bite point.

Animals↗
PubMed1975

The pulvinar nucleus of Galago senegalensis.

The present study was undertaken to analyze the connections of the pulvinar nucleus in a prosimian. The experiments, which rely on the Fink-Heimer ('67) method for staining degenerating axons and their terminals, fall into two parts: first, the tracing of ascending tectal projections to the caudal thalamus and second, the tracing of projections from this thalamic target to the cortex. Large lesions of the superior colliculus resulted in dense degeneration in the caudal half of the inferior subdivision of the pulvinar complex. This pathway could be identified when the lesion was restricted to the superficial layers of the superior colliculus, signifying that it is a visual pathway. In general, the projections of the deep and superficial layers of the superior colliculus were distinct and in this respect Galago resembles Tupaia. The inferior pulvinar nucleus in turn projects to area MT, a conspicuous subdivision of the temporal cortex. The superior division of the pulvinar, in contrast to the inferior division, is not a major target of ascending projections from the superior colliculus and projects to the areas of the occipital and temporal lobe intercalated between areas MT and 17. When these results are compared with similar studies in nonprimates, notably studies of Tupaia, a striking difference in organization emerges. In Tupaia, and in distantly related mammals such as the squirrel, the target of the tecto-pulvinar system includes area 18 adjacent to area 17. This feature is important since the two parallel projection systems seem to be related to each other in terms of the way in which the zero vertical meridian is spatially represented. However, in Galago the subdivision of the pulvinar receiving projections arising from the superior colliculus does not project to area 18. Area 18 is indeed the target of pulvinar projections, but these projections arise from that portion of the pulvinar which is not a recipient of ascending tectal projections. It is not easy to see how this primate organization, if indeed the Galago is representative of primates, evolved from the organization reflected in Tupais.

Animals↗
PubMed1979

Layer I of striate cortex of Tupaia glis and Galago senegalensis: projections from thalamus and claustrum revealed by retrograde transport of horseradish peroxidase.

We have examined the origin of the subcortical projections to the superficial layers of the striate cortex in Tupaia glis and Galago senegalensis by using the retrograde transport of HRP. Crystals of HRP were laid directly on the moist pial surface of the cortex which had been gently pricked with a small glass pipette. The diffusion of HRP was limited to layers I and II by restricting the length of time that the HRP was in contact with the surface. Following the application of HRP to the striate cortex, labeled cells were found in restricted regions of the lateral geniculate body of both species. Layers 4 and 5 of galago and layer 3 of tree shrew contained dense clusters of labeled cells. Labeled neurons were also found in the zones between the layers of the lateral geniculate body in both species and these cells were always in register with the labeled cells within the layers. In galago, curved columns of labeled cells were observed in the inferior and superior subdivisions of the pulvinar nucleus. These columns were arranged in the shape of two arcs, joined at the fiber bundle which separates the two subdivisions. The position of the bands in the pulvinar nucleus varied with the locus of the application in the striate cortex. While no labeled cells were seen in the body of the pulvinar nucleus of tree shrew, small labeled neurons were found in the external medullary lamina forming the capsule of the pulvinar nucleus. These cells were continuous with a larger population of labeled cells in the lateral intermediate nucleus. In both species, labeled cells were also found in the intralaminar nuclei (particularly the paracentral nucleus) and in the dorsal-caudal portion of the claustrum. In the claustrum, few unlabeled neurons were present within the zone containing labeled cells. In conclusion, layer I os striate cortex appears to be the site of convergence of several projection systems originating from principal and intralaminar thalamic nuclei as well as the claustrum. The significance of this overlap is discussed in terms of the total cortical extent of each system.

Animals↗
PubMed1975

Dorsal root afferents to clarke's column from hindlimb cord levels in Tupaia and Galago.

The projection of hindlimb dorsal root afferents to Clarke's column has been studied in the tree shrew (Tupaia glis) and lesser bushbaby (Galago senegalensis). In the bushbaby, fibers from K12, L1 and L3 projected ipsilaterally to Clark's nucleus from levels L3 to T3, L2 to T4 and L3 to T5 respectively. In Tupaia, afferents from T11, L1, and L3 terminated ipsilaterally within the nucleus from segments L2 to T4, L3 to T6, and L3 to T8. Fibers from T12, L1, and L3 in Galago and T11 in Tupaia terminated within the even to lateral aspect of the nucleus at lower levels, throughout the nucleus at middle levels and in the dorsal aspect of the column at rostral levels. Fibers from T11 and L1 have a similar ventrolateral pattern of termination in lower levels, however, at rostral levels preterminal debris was present throughout the width of the nucleus. Fibers from L1 and L3 in the bushbaby form a complex longitudinal network with the medullary region of the nucleus in segments T11 to T8. Afferents from levels T5 in Tupaia and L6 in Galago projected ipsilaterally to the nucleus from level L3 to T10, and T8, respectively. Fibers from these segments terminated throughout the extent of the column at L3 and, rostrally projected to more dorsal regions of the nucleus. In this study, fibers from S2, and S3 and CCO2 did not terminate in Clark's column. Both the segmental distribution of hindlimb dorsal root fibers and their pattern of termination in Clark's nucleus in the tree shrew were similar to that reported in quadrupedal primates and other quadrupedal mammalian forms. The results of this study were interpreted as evidence which relates the complex organization of the Clark column system in the lesser bushbaby to its vertical clinging and leaping style of locomotion.

Animals↗
PubMed1975

The rubrospinal tract in a prosimian primate, Galago senegalensis.

The spinal distribution of rubrospinal fibers is described in the lesser bushbaby (Galago senegalensis), a prosimian primate. The tract is composed of thick and thin fibers, extends the length of the cord in the lateral funiculus, and is located ventral and ventrolateral to the lateral corticospinal tract and medial to the dorsal spincerebellar tract. There is a topographical relationship between origin and termination of rubrospinal fibers in Galago. Dorsomedial areas of the red nucleus project primarily to contralateral lumbar and sacral levels. Thoracic fibers arise from intermediate regions of the nucleus. Rubrospinal fibers in Galago terminate in basilar regions of the dorsal horn mainly at cervical and lumbar levels. Degeneration is most concentrated in medial and lateral portions of lamina V-VII. Although degenerated fibers approached the midline, none could be traced to the contralateral side. Lesions of more extensive portion of the nucleus resulted in degeneration in Clarke's column especially evident in low thoracic and upper lumbar levels. The latter connection may represent one rubrocerebellar feedback loop in the lesser bushbaby.

Animals↗
PubMed1979

A quantitative approach to cytoarchitectonics. IV. The areal pattern of the cortex of Galago demidovii (e. Geoffroy, 1796), (lorisidae, primates).

The boundaries of neo- and allocortical areas of Galago demidovii are analyzed with an automatic quantitative procedure using an image analyzer. The results are summarized in a cortical map and compared with a cortical map of Tupaia. Galago shows a highly differentiated temporal lobe and no homogeneous peristriate area comparable to the classical concept of Brodmann's Area 19. Primary motor, somatosensory, auditory, and visual areas are delineated and shown to be surrounded by distinct secondary areas.

Animals↗
PubMed1979

Some aspects of the organization of the lateral geniculate nucleus in Galago senegalensis revealed by using horseradish peroxidase to label relay neurons.

Following injection of horseradish peroxidase into area 17 of the prosimian Galago senegalensis, columns of labeled neurons are seen in the dorsal lateral geniculate nucleus extending through all cell layers. Individual counts of the number of labeled and unlabeled neurons reveal that from 91 to 98% of all neurons within these densely labeled columns are labeled. These results indicate that most of the neurons within the LGN of the bushbaby project to striate cortex. Average diameter measurements of labeled and unlabeled cells within the labeled columns were used to determine whether cell layers could be separated into two types (parvocellular and magnocellular) or three types (small, medium, and large) on the basis of cell body size. These measurements indicate that the LGN of the bushbaby is composed of two layers each of small (layers 4 and 5), medium (layers 3 and 6), and large (layers 1 and 2) relay neurons. These observations are consistent with the conclusion that layers 1 and 2 in the LGN of Galago are homologous with the magnocellular layers, and layers 3 and 6 homologous with the parvocellular layers, identified in the LGN of New and Old World monkeys.

Animals↗
PubMed1975

Behavioral study of the visual cortex of Galago senegalensis.

An ablation study of the visual cortex of Galago senegalensis was undertaken in the hope of finding clues about the evolution of primate visual cortex. Removal of area 17 resulted in a profound sensory loss manifested by, first, the failure to discriminate between simple patterns; second, a deficit in localizing objects; third, a deficiency in tracking moving objects; and fourth, symptoms attributable to a deficiency in depth perception, such as misreaching and inaccurate jumping. Thus, the effects of ablating area 17 are similar in bushbabies and monkeys. In contrast, minimal sensory loss is produced by ablating area 17 in squirrels or tree shrews. This difference between primates and other mammals may depend on differences in the extent of the cortical target of the tecto-pulvinar path; in Galago and perhaps in all primates, more of the extrastriate visual cortex is entirely dependent on area 17. Removal of the ventral temporal cortex resulted in a loss of learned visual discriminations and in retardation in learning new visual discriminations. These symptoms seem related to the inferotemporal syndrome in monkeys.

Animals↗
PubMed1975

Origin, course and termination of corticospinal fibers in a prosimian primate, Galago.

This report describes the origin, course, and termination of cortical projections to the spinal cord in the bushbaby, Galago, Although the position and extent of these projections are similar to those reported in other primates, there is also (1) a somatotopic organization present in the motor-sensory cortex and in its projections to the spinal cord, and (2) additional nuclei in the medial base of the dorsal and ventral horn which receive afferents from the motor-sensory amalgam. This medial organization may be related to the innervation of axial musculature in Galago, an animal displaying a vertical clinging and leaping locomotive behavior.

Animals↗
PubMed1975

Cerebellar corticovestibular fibers of the posterior lobe in a prosimian primate, the lesser bushbaby (Galago senegalensis).

The orginization of cerebellar corticovestibular fibers was studied in a prosimian primate (Galago senegalensis) using the Fink and Heimer ('67) method. The vestibular complex of Galago is larger than in other mammals and some higher primates. Vermis lobule IX contributes the largest number of fibers to the ipsilateral vestibular complex. Lobules VI and VIII give rise to lesser, but similar, numbers of fibers which also pass into the ipsilateral vestibular nuclei. Vermis lobule VII and the paravermal and lateral cortices contribute extremely sparse numbers of fibers to the dorsal area of the ipsilateral vestibular complex. All degenerated fibers enter the vestibular nuclei through a large diffusely organized juxtarestiform body. Fibers from vermis lobule VII and the paravermal and lateral cortices terminate in dorsal areas of the ipsilateral vestibular nuclei. Vermis lobule VI projects into dorsal and lateral regions of the ipsilateral SVN, LVN and SpVN. Vermis lobules VIII and IX project into the dorsal and into progressively more central and medial regions of the ipsilateral SVN, LVN, and SpVN. This gives the clear impression of a rostro-caudal origin of fibers from the posterior lobe vermis which terminate in an overlapping lateral to medial sequence in the vestibular complex. In addition to its projection into the vestibular nuclei, lesions of vermis lobule IX also elicit degeneration in dorsal areas of the ipsilateral medullary reticular formation and in the ipsilateral parabrachial nuclei.

Animals↗
PubMed1977

Urine marking and territoriality in Galago alleni (Waterhouse, 1837--Lorisoidea, Primates)--a field study by radio-telemetry.

A wild population of Galago alleni was controlled by trapping and followed by radio-tracking in the equatorial rainforest of Gaboon during three study periods of 3 months each in 1972, 73 and 75. The disposition of territories and the social organization are described, as well as their evolution through time. A new technique of radio telemetry permitted identification and localization of urine marking in wild galagos. Urine marking took place throughout the territory, with a fourfold increase in frequency in zones where there is a slight overlap with neighbouring territories (female--female or male--male). The function of urine washing (wetting of the soles of the feet with urine) is discussed in relation to five hypotheses proposed by different authors, and th data obtained in the field in Gaboon. We interpret this behaviour as a means of dispersal of urine marks (social signals) in a three-dimensional milieu where displacement by a combination of leaping and running creates numerous pathways.

Animals↗