Adrenergic retinal neurons

Summary Adrenergic retinal neurons have been studied in cynomolgus monkeys, cats, rabbits, guinea-pigs, rats, and mice with the fluorescence technique of Falck and Hillarp. With some species variations, three adrenergic fibre layers have been observed: an outer adrenergic fibre layer (all species) at the border between the inner nuclear and inner plexiform layers, a middle adrenergic fibre layer (rabbits, guinea-pigs, rats, and mice) in the middle of the inner plexiform layer, and an inner adrenergic fibre layer (rabbits) at the border between the inner plexiform layer and the ganglion cell layer. Similarly, three kinds of adrenergic nerve cells have been found: a somewhat heterogenous group of outer adrenergic cells (all species) situated in the innermost cell rows of the inner nuclear layer, eremite cells (rabbits, guinea-pigs, rats, and mice) within the inner plexiform layer and alloganglionic cells (all species) with a position and appearance resembling some of the ordinary non-adrenergic cells of the ganglion cell layer. All the adrenergic cells are star-shaped with slender branching processes running to the different adrenergic layers.The research reported in this document has been sponsored by the Air Force Office of Scientific Research under grant AF EOAR 66-14 through the European Office of Aerospace Research (OAR), United States Air Force, by the United States Public Health Service (grant no. NB 05236-02), by the Swedish Medical Research Council (grant no. B 66-320), and by the Faculty of Medicine, University of Lund, Sweden.     

Life history patterns of new world monkeys

Allometric methods are used to investigate the life history patterns of New World monkeys. These patterns are compared to those found in other haplorhines and links with ecology are explored. The life history characteristics of the cebid monkeys suggest that these species are primarily slow breeding and slow developing for primates of their size. I suggest that these characteristics arose during a long period of adaptation to stable rainforest habitats. The capuchins and squirrel monkeys are a notable exception to the general rule that genera found outside primary forests will have a “fast” life history. In the marmosets and tamarins selection for small size and high birth rate has occurred, probably as a result of their adapting to more secondary habitats. It is this selection for rapid breeding, combined with the preadaptation of paternal care, that has probably led to twinning in these species. The evidence presented indicates that it is unlikely that twinning arose as a direct result of the mechanical constraints of small size but is more probably due to selection for increased reproductive output.     

Animal behaviour: old world monkeys build new world order

New experimental evidence shows that policing behaviour by dominant monkeys stabilizes and integrates macaque societies.     

Carbonic anhydrase II in new world monkeys

Carbonic anhydrase II electrophoretic patterns were investigated in 3113 animals belonging to 12 genera and 24 species of New World primates. Polymorphism was detected in 13 species. A total of 24 different alleles was postulated to explain the variability found; the genusAotus showed the highest (eight) number of such alleles. Three genera of the family Callitrichidae (Callithrix, Saguinus, andCebuella) presented five alleles that were not found among the Cebidae. Important markers at the generic level were observed inCallicebus (CA2 ^*6 andCA2 ^*12),Cebus (CA2 ^*10, CA2^*16, andCA2 ^*21), andAotus (CA2^*3, CA2^*4, CA2^*5, CA2^*9, CA2^*15, CA2^*17, CA2^*22, CA2^*23). CA2^*13 seems to be the most common allele among the Cebidae; six genera of this family showed frequencies higher than 70% of it.     

Allomothering behaviour of new and old world monkeys

The holding or transferring of newborn infants at less than 1 month old by individuals other than the mothers was studied in 24 species of New and Old World monkeys under captive conditions. The observed monkey species could be divided into two types. Group A included eight species of three families where the mothers were tolerant to ‘infant transfer’ and readily retrieved their infants from other individuals, the frequency of infant transfer being high. The infant transfer of this group was termed allomothering behaviour. Group B included 16 species of two families where infant transfer did not occur at all or its frequency was very low and the mothers were possessive of their infants. Once transfer did occur, the infant could not be reclaimed with ease. The relationships between the two groups and taxonomic status, life forms and social types were evaluated in a total of 45 species from the present study and the literature. Correspondences were found with social type and taxonomic status. That is, species of Group A were seen only in the family or one-male type, except for one species, although none of this group appeared in the Cercopithecinae regardless of social types. The significance of infant transfer is discussed in relation to the participants' responses to it and the correlations between the two groups and social types.     

Model life tables for the smaller new world monkeys

Mortality statistics from five populations of small New World monkeys (includinsg Callithrix jaccus, Leontopithecus rosalia, Saguinus fuscicollis, and Saguinus oedipus) were combined to generate a standard model life table reflecting the mortality patterns of these primates. The model is applied to three individual populations to illustrate a strategy for smoothing and interpolating mortality statistics of varying completeness and quality. © 1993 Wiley-Liss, Inc.     

Chromosome evolution in new world monkeys (platyrrhini)

During the last decades, New World monkey (NWM, Platyrrhini, Anthropoideae) comparative cytogenetics has shed light on many fundamental aspects of genome organisation and evolution in this fascinating, but also highly endangered group of neotropical primates. In this review, we first provide an overview about the evolutionary origin of the inferred ancestral NWM karyotype of 2n = 54 chromosomes and about the lineage-specific chromosome rearrangements resulting in the highly divergent karyotypes of extant NWM species, ranging from 2n = 16 in a titi monkey to 2n = 62 in a woolly monkey. Next, we discuss the available data on the chromosome phylogeny of NWM in the context of recent molecular phylogenetic analyses. In the last part, we highlight some recent research on the molecular mechanisms responsible for the large-scale evolutionary genomic changes in platyrrhine monkeys.     

Adrenergic neurons in teleost retina

Summary The adrenergic retinal neurons of perch and trout were studied with the fluorescence microscopical method of Falck and Hillarp. Pilot studies were also performed on pike, plaice, cod, eel, goldfish, cunner, black moor, cichlid and carp. Only minor differences were noted between the species.Adrenergic varicose terminals occur in three sublayers of the inner plexiform layer. The layer adjacent to the ganglion cells is the most elaborate. Adrenergic perikarya occur in the innermost cell rows of the inner nuclear layer, sending branches to all sublayers of the inner plexiform layer. Adrenergic perikarya also occur among the ganglion cells, sending their branches to the innermost sublayer of adrenergic fibres in the inner plexiform layer. Weakly fluorescent adrenergic fibres can be seen running through the entire depth of the inner nuclear layer. They originate from the adrenergic perikarya of the inner nuclear layer, and they end in an elaborate plexus of adrenergic terminals among the horizontal cells. Either of the horizontal cell types can be in contact with adrenergic terminals, but the middle horizontal cells have the greatest density about them, being surrounded by baskets of adrenergic terminals of presumably synaptic character. It cannot be excluded that some horizontal cells contain a catecholamine.Microspectrofluometry revealed dopamine in the perch and trout retinal neurons.The research reported in this document has been sponsored by USPHS Grant No. 06092 and by a Research Professorship from Research to Prevent Blindness, Inc. to A.M.L. and by the Swedish Medical Research Council (B69-14X-712-04C and B68-14X-2321-01).     

Degrees of sexual dimorphism in Cebus and other new world monkeys

Sexual dimorphism in primate species expresses the effects of phylogeny, life history, behavior, and ontogeny. The causes and implications of sexual dimorphism have been studied in several different primates using a variety of morphological databases such as body weight, canine length, and coat color and ornamentation. In addition to these different patterns of dimorphism, the degree to which a species is dimorphic results from a variety of possible causes. In this study we test the general hypothesis that a species highly dimorphic for one size-based index of dimorphism will be equally dimorphic (relative to other species) for other size-based indices. Specifically, the degree and pattern of sexual dimorphism in Cebus and several other New World monkey species is measured using craniometric data as a substitute for the troublesome range of variation in body weight estimates. In general, the rank ordering of species for dimorphism ratios differs considerably across neural vs. non-neural functional domains of the cranium. The relative degree of sexual dimorphism in different functional regions of the cranium is affected by the independent action of natural selection on those regions. Regions of the cranium upon which natural selection is presumed to have acted within a species show greater degrees of dimorphism than do the same regions in closely related taxa. Within Cebus, C. apella is consistently more dimorphic than other Cebus species for facial measurements, but not for neural or body weight measurements. The pattern in C. apella indicates no single best measurement of the degree of dimorphism in a species; rather, the relative degree of dimorphism applies only to the region being measured and may be enhanced by other selective pressures on morphology. Am J Phys Anthropol 107:243–256, 1998. © 1998 Wiley-Liss, Inc.     

Chromosome numbers of some new world species of Thelypteris

Chromosome numbers of 19 species ofThelypteris from Florida, California, Mexico, and Costa Rica are reported. First counts are given for two species belonging to sect.Goniopteris (x = 36), one species of sect.Leptogramma (x = 36) and seven species of the Opposita group (x = 29). The last named group is remarkable for the relatively low number of diploid taxa so far known. The base numbers 36, 35, 34, 32, 31, 30, 29, and 27 are known in the Thelypteridaceae, with 36 being the most common number throughout the tropics, and perhaps the ancestral base number. The temperate American species ofThelypteris are probably more closely allied toParathelypteris H. Ito, from Asia, than to the Neotropical species of the Opposita group.     

Adrenergic and cholinesterase-containing neurons of the heart

Summary The adrenergic and acetylcholinesterase-containing nerves of the hearts of mice, rats, guinea-pigs, rabbits, and cats were studied. The fluorescence technique of Falck and Hillarp was used for the demonstration of adrenergic nerves, whereas a modified Koelle cholinesterase technique was used for the cholinesterase-containing nerves. The inhibitors used were Mipafox, iso-OMPA and Nu 683. Microspectrofluorometry was used to identify the structures containing dopamine.Adrenergic as well as acetylcholinesterase-containing fibres were found in all parts of the heart, most abundantly in the atria. Dense nerve plexa supplied the sinoarial and atrioventricular nodes. There was a plexus of both fibre types in the endocardium and on the atrial side of the valves. In the valves, it could be shown that adrenergic and cholinesterase-containing fibres ran closely parallel to each other. Indirect evidence suggested that this applies also to the myocardium.No nerve fibres containing dopamine were revealed in the microspectrofluorometer. The dopamine previously found in the atria seems, instead, to be situated in so-called small intensely fluorescent cells.No adrenergic ganglion cells were found in the heart despite extensive search. The vagus of rabbits was found to contain only few adrenergic preterminals.     

Comparative and functional myology of the prehensile tail in new world monkeys

The caudal myology of prehensile-tailed monkeys (Cebus apella, Alouatta palliata, Alouatta seniculus, Lagothrix lagotricha, and Ateles paniscus) and nonprehensile-tailed primates (Eulemur fulvus, Aotus trivirgatus, Callithrix jacchus, Pithecia pithecia, Saimiri sciureus, Macaca fascicularis, and Cercopithecus aethiops) was examined and compared in order to identify muscular differences that correlate with osteological features diagnostic of tail prehensility. In addition, electrophysiological stimulation was carried out on different segments of the intertransversarii caudae muscle of an adult spider monkey (Ateles geoffroyi) to assess their action on the prehensile tail. Several important muscular differences characterize the prehensile tail of New World monkeys compared to the nonprehensile tail of other primates. In atelines and Cebus, the mass of extensor caudae lateralis and flexor caudae longus muscles is more uniform along the tail, and their long tendons cross a small number of vertebrae before insertion. Also, prehensile-tailed monkeys, especially atelines, are characterized by well-developed flexor and intertransversarii caudae muscles compared to nonprehensile-tailed primates. Finally, Ateles possesses a bulkier abductor caudae medialis and a more cranial origin for the first segment of intertransversarii caudae than do other prehensile-tailed platyrrhines. These myological differences between nonprehensile-tailed and prehensile-tailed primates, and among prehensile-tailed monkeys, agree with published osteological and behavioral data. Caudal myological similarities and differences found in Cebus and atelines, combined with tail-use data from the literature, support the hypothesis that prehensile tails evolved in parallel in Cebus and atelines. © 1995 Wiley-Liss, Inc.     

Will travel for food: spatial discounting in two new world monkeys

Nonhuman animals steeply discount the future, showing a preference for small, immediate over large, delayed rewards. Currently unclear is whether discounting functions depend on context. Here, we examine the effects of spatial context on discounting in cotton-top tamarins (Saguinus oedipus) and common marmosets (Callithrix jacchus), species known to differ in temporal discounting. We presented subjects with a choice between small, nearby rewards and large, distant rewards. Tamarins traveled farther for the large reward than marmosets, attending to the ratio of reward differences rather than their absolute values. This species difference contrasts with performance on a temporal task in which marmosets waited longer than tamarins for the large reward. These comparative data indicate that context influences choice behavior, with the strongest effect seen in marmosets who discounted more steeply over space than over time. These findings parallel details of each species' feeding ecology. Tamarins range over large distances and feed primarily on insects, which requires using quick, impulsive action. Marmosets range over shorter distances than tamarins and feed primarily on tree exudates, a clumped resource that requires patience to wait for sap to exude. These results show that discounting functions are context specific, shaped by a history of ecological pressures.     

Alkaloid distribution in some new world Lupinus species

Alkaloidal profiles of 21 Lupinus species indigenous to North and South America have been determined. Nineteen quinolizidine alkaloids were identified, including aphyllidine and N-methylcytisine, which have not previously been found in the genus. Two dipiperidine alkaloids were also detected. The pattern of alkaloidal distribution is related to a taxonomic classification of the genus.     

Geophagy in new world monkeys (Platyrrhini): ecological and geographic patterns

Geophagy has been recorded in an increasing number of New World monkeys (Platyrrhini) over recent years, permitting a tentative analysis of ecological patterns. While geophagy has now been recorded in species representing all 4 platyrrhine families and a majority of genera, there is a marked tendency for it to occur in the larger-bodied Pitheciidae and Atelidae. Howlers (Alouatta) are responsible for almost a third of reports, which are concentrated in the more frugivorous species, Alouatta belzebul and Alouatta seniculus. Geophagy may also be relatively common in the spider monkeys (Ateles) and the pitheciids, which are specialised frugivores and seed predators, respectively. An overview of the available data points to a marked Amazonian bias, allowing for geographical differences in the number of species and field studies. This pattern is demonstrated most emphatically by Alouatta, for which there are almost as many reports as field studies in the Amazon basin, in stark contrast with Central American sites, which have a long tradition of fieldwork, but no published records of geophagy. There are also relatively few reports from the Brazilian Atlantic forest. Despite the growth in reports, and the patterns identified here, the functional aspects of geophagy in the platyrrhines still remain unclear.     

The expression of aggression in old world monkeys

The expression of agonistic behavior in adult and juvenile members of both sexes was studied in groups of from 23 to 93 animals representing Macaca mulatta, M. arctoides, M. nemestrina, M. nigra, and Cercocebus atys. Data were collected using focal animal techniques over a period of 1 year for each group. Adult male biting was notably infrequent in all cases, and adult male participation in agonistic encounters was less frequent than for any other age-sex class, especially in the groups with the highest agonistic rates. Adult male agonistic behavior was often expressed as aggression but seldom involved contact forms of aggression, and biting constituted the smallest proportion of contact aggression for all age-sex classes. Adult males were also seldom the targets of aggression and had the highest rates for shaking of objects and bouncing displays. A tendency for the most severe forms of aggressive expression to be most frequent in those animals least capable of inflicting injury was noted in all groups, along with a tendency for aggression to be directed toward immature animals. Sex differences in aggressive expression and responses to aggression were noted, but the frequency of receipt of aggression was not directly reflected in the wounding noted. Different means to achieve the same consequence, infrequent adult male damaging attacks, are suggested to operate in the several groups studied.