Its known that the age-related decline in cognitive facilities is not due to the loss of neurons but more subtle changes in specific areas of the brain. Structural and morphological changes in cellular alignment in the minicolumns correlate with increased prevalence of neurological diseases and in aging. In the rhesus monkey, cognitive decline is similar to what humans experience in aging. In the monkey prefrontal cortex, Brodmann area 46, an important region for executive functioning, cognitive decline correlates with changes in cellular alignment or “columnar strength” as studies by Cruz et al., (2009). Using the density maps method in Area 46, the ventral bank was identified to be the most susceptible to structural changes. Minicolumns, are defined by the cellular alignment of neurons in the cortex and some believe that the dendritic bundles of neurons in the cortex is also considered an integral part of the columns. The functional role of apical dendrites, is not well understood, however, given the that repeated organized bundles transverse through the laminae could be further support for their inclusion in minicolumns with possible functional importance. If structural changes such as loss of columnar strength (neuronal displacement) that correlates with cognitive aging, it is possible that the dendritic organization may also be affected in this area. In this thesis, it is hypothesized that the dendritic bundles in this area could also be related to the cognitive deficits associated with normal aging. Using double- fluorescence labeling for dendrites (MAP-2) and neurons (Neu-N), 3D confocal reconstructions of the dorsal and ventral banks of Area 46 were used to investigate structural/morphological changes in the dendritic bundles in young and old rhesus monkeys. While cortical thickness and apical dendritic length between both banks did not change, we found a significant increase in inter-bundle spacing at layer 6A in the older monkeys in the ventral bank. Inter-bundle spacing for bundles in layer 5 was measured and showed that the young consistently have smaller inter-bundle spacing. Future studies with larger sample size will also investigate whether changes in dendritic bundles and their organization also correlate with age-related cognitive deficits.

This thesis investigated effects of manipulative experience on tool-using ability of tufted capuchins. Two groups of capuchins were tested on variations of a tool-using task, involving use of an object as a tool to dislodge a reward from a tube. The tasks were modelled after those developed by Visalberghi and Limongelli (1994) and Visalberghi and Trinca (1989). One group of monkeys was provided the opportunity to manipulate task materials without reward; the other group was not. Experiment 1 required subjects to push a rod through the tube. Experience with task materials improved capuchins' efficiency, evidenced by faster completion of trials. In Experiment 2, short pipes could be combined to create a tool of sufficient length. Due to procedural problems, results were inconclusive. Experiment 3 required subjects to manufacture the appropriate tool. Experience with task materials improved capuchins' performance, evidenced by faster completion of trials, less frequent performance of inefficient behaviours, and decrease in errors across trials. When capuchins' performance was compared with enculturated chimpanzees tested previously on the task (Visalberghi, Fragaszy, and Savage-Rumbaugh, 1995), experienced capuchins performed as efficiently after 15 trials as had chimpanzees originally. In Experiment 4, subjects had to dislodge the reward from a tube containing a trap. Because successful levels of performance were not reached, results were inconclusive. In Experiments 5 and 6, appreciation of object affordances was examined. The capuchins demonstrated an ability to distinguish between functional characteristics of objects. These results suggest previous claims regarding limitations of capuchin tool-use may have underestimated their abilities. Further, because object experience enhances tool-using ability, previous comparisons of capuchins with enculturated chimpanzees seem to have misrepresented the magnitude of difference in their abilities. However, future research comparing species with the same experiential backgrounds is necessary to elaborate on differences in cognitive processes underlying capuchin and chimpanzee tool-using behaviour.

It is hypothesised that young baboons are potentially vulnerable to the effects of seasonal stress. Data were collected on the behaviour of this age group during a 12 month field study of a troop of olive baboons (Papio anubis) on the Laikipia plateau, Kenya, using a hand-held computer and a new program written by the author. Long-term environmental records for this site were continued. At this site there is a seasonal pattern of rainfall with inter-annual variation. Measures of biomass indicate that there are seasonal fluctuations in baboon food availability. Patterns in the occurrence of one component of the baboon's diet, Acacia species, are presented. The varying behaviour of the troop as a whole is related to food availability. Differential use of the home range and observed sub-trooping behaviour are interpreted as adaptive strategies for living in a seasonal environment. Developmental change in the behaviour associated with the mother-offspring relationship is described. Patterns in the time spent in contact with and close proximity to the mother from this site are compared with those from other sites, and striking similarities are found. Many of the behavioural activities of infants and young juveniles, i.e. feeding, moving, types of exploring, visually attending, grooming, and receiving affiliative approaches, exhibit patterns of developmental change. Interactions between activities are examined in the context of the complete activity budget. The effect of seasonal stress on young baboons is examined by using a technique of curve fitting. Data are compared between periods of higher and lower food availability. Significantly more time is spent feeding and less time spent in social and attending activities in the 'worst' than the 'best' months. Young baboons vary their diets seasonally. There is evidence that older infants (weanlings) are more vulnerable to the impact of seasonal stress than either young infants or young juveniles.

This thesis investigates the nature of post-conflict behaviour and relationships among individuals in two captive groups of pigtail macaques, Macaca nemestrina, and one wild troop of olive baboons, Papio anubis. Data were collected during periods of seven and twelve months respectively. In both pigtail groups, conflicts were more frequently reconciled between opponents with strong affiliative ties. However, reconciliation was twice as common in the well-established group where individuals' social networks were more compact. It is argued that the more intense ties produced by restricted networks increased the likelihood of reconciliation. Reconciliation was demonstrated among wild olive baboons, occurring at a rate consistent with a relatively intolerant dominance style. Opponents who were close kin or of similar rank reconciled relatively frequently, but reconciliation rarely followed conflicts associated with food. Olive baboons did not 'console' each other, consistent with the hypothesis that consolation requires an ability to empathise with victim distress. Initiation of post-conflict attacks on third parties was not elevated in victims of aggression. Among the baboons, both victims and initiators of aggression exhibited elevated rates of post-conflict self-directed behaviour (a combined measure of scratching, autogrooming, body-shaking and yawning). Reconciliation reduced both SDB and the incidence of further aggression. However, reconciliation only reduced SDB among individuals involved in conflicts in which they had both received and delivered aggression. Female baboons showed significantly higher rates of SDB when their nearest neighbour (within 5 m) was a dominant conspecific than when he or she was a subordinate individual, supporting the hypothesis that SDB indexes stress in primates. This result suggests that SDB can be used to index relationship security in primates.

The problems of what primates communicate with their vocalizations and to what extent they refer to events in the external environment are raised in numerous studies of primate vocal communication. To investigate these issues, I concentrate on the calls of two primate species with a similar fission-fusion social organization. I report here the results of a one year field study on the Central American spider monkey (Ateles geoffroyi frontatus) and of a captive study on the chimpanzee (Pan troglodytes). I collected observational data and conducted playback experiments on two types of calls of the spider monkey, whinnies and alarm barks. Spider monkeys use two functionally distinct whinnies, a feeding whinny and a locational whinny. Detailed acoustic analyses of whinnies given in different contexts showed that in three females an acoustic feature-number of arches in the fundamental frequency of the call- could be used to differentiate between them. Although the whinnies of different monkeys within the same community exhibit enough acoustical differences for individual vocal recognition to take place, spider monkeys did not discriminate familiar individuals' whinnies from those of strangers from another community. In predator contexts spider monkeys use barks to attract other conspecifics to a site. However, my data do not support the existence of two types of alarm barks for aerial versus terrestrial predators. I conducted two different types of experiments on the calling behaviour of captive chimpanzees in response to food-finding. I examined whether the quantity and divisibility of food, or the presence of an audience, influence calling behaviour. Chimpanzees' food- associated calls, i.e. rough grunts, functioned to indicate food availability, and they were produced or suppressed depending on how shareable the food was and whether or not other individuals were nearly. Several spider monkeys' and chimpanzees' calls have the ability to function referentially, but cannot be considered devoid of a motivational content.

Analisou-se pelves de 72 primatas neotropicais, adultos, 42 machos e 30 fêmeas não prenhes, da espécie Aotus azarai infulatus, para obtenção dos diâmetros pélvicos, in vivo, e compará-los com o dimorfismo sexual, correlacionando-os com a biometria corpórea e a origem dos animais. Mensurou-se nas radiografias em projeção ventro-dorsal, digitalizadas, os diâmetros biilíaco superior, biilíaco inferior, biilíaco médio, diagonal direito, diagonal esquerdo, sacro púbico e área da entrada da pelve. As médias verificadas foram: para o comprimento do corpo 30,94 cm; comprimento da cauda 35,63 cm; perímetro do tórax 18,97 cm; perímetro da pelve 17,11 cm e o peso 0,96 g. As médias verificadas para o DDD da pelve foram 2,61 cm; DDE 2,66 cm; DBIM 1,97 cm; DBIS 1,41 cm; DBII 1,58 cm; DSP 2,48 cm e a AEP 3,85 cm. Concluiu-se com o estudo que tendo sido verificados os diâmetros biilíaco médio menores do que os diâmetros sacro-púbico tanto nos machos quanto nas fêmeas, pode-se dizer a pelve de Aotus azarai infulatus é classificada como dolicopélvica e existe dimorfismo sexual em relação às pelves Aotus azarai infulatus adultos. / Related data to the diameters of the pelvis from 72 Neotropical primates, owl monkeys (Aotus azarai infulatus), 42 adult males and 30 adult non-pregnant females, were obtained in vivo by ventrodorsal projection radiographic exams, compared between sex and correlated with the measures of the body and their origin. The mean values of the body length (30.94 cm), tail length (35.63 cm), thoracic perimeter (18.97 cm), hip perimeter (17.11) and the weight (0.96 g) were verified. The radiographic images were digitalized and the superior biiliac (DBIS), inferior biiliac (DBII), medium biiliac (DBIM), right diagonal (DDD), left diagonal (DDE), sacrum-pubic diameters (DSP) and the inlet pelvic area (AEP) were measured. The mean values were DBIS 1.41 cm; DBII 1.58 cm; DBIM 1.97 cm; DDD 2.61 cm; DDE 2.66 cm; DSP 2.48 cm; AEP 3.85 cm. In conclusion, once medium biiliac diameters were minor than sacrum-pubic diameters in males and females, the pelvis from Aotus azarai infulatus can be classified as dolicopelvic and we also conclude there is pelvic sexual dimorphism in adult owl monkeys (Aotus azarai infulatus).

Masters of Science / Gonadotropin Releasing Hormone (GnRH) is a hypothalmic decapeptide, which regulates mammalian gonadotropin secretions by binding to specific, high affinity receptors in the pituitary. Two forms of GnRH (GnRH I and GnRH II) are expressed in the brain of human and some primates. Even though primates have been used extensively in a variety of investigations in relation to the role of GnRH in reproduction, there is no evidence of any research to investigate the direct effect of GnRH on primate sperm. / South Africa

Magister Scientiae (Medical Bioscience) - MSc(MBS) / The present study describes molecular aspects of inherited congenital cataract in captive-bred Vervet monkeys. Congenital cataracts are lens opacities that are present at birth or soon after birth and include hereditary cataracts or cataracts caused by infectious agents. The MRC Primate Unit is housing a colony of captive-bred Vervet monkeys in which 7.5% is suffering from congenital cataract. However, the parents of the affected individuals were asymptomatic. Six families within the colony have been identified to be affected by two types of morphologies (Y-sutural and total cataract). Based on the evidence provided above, it was speculated that the colony was affected with autosomal recessive cataract. The main aim of this study was to facilitate a strategy for managing breeding programs by minimizing cataract occurrences in captive-bred Vervet monkeys. Integrated combination of clinical, molecular and bioinformatic strategies were used to identify and assess reciprocal candidate susceptibility genes for cataracts. The genes that are known to be responsible for most human congenital cataract cases were prioritized. The genes include Heat shock transcription factor 4 (HSF4), Crystalline Alpha A (CRYAA), glucosaminyl (N-acetyl) transferase 2 (GCNT2) and Lens intrinsic membrane protein 2 (LIM2). Twenty two subjects were selected based on their morphology (5 carriers, 5 controls and 12 cataracts). 2ml of blood was collected for Deoxyribonucleic acid (DNA) extraction. Coding exons and flanking regions were screened by polymerase chain reaction (PCR) amplification and sequenced. The CLC DNA workbench was used for results analysis. The screening of four genes revealed 20 sequence variants which were not present in the control individuals. Sequencing of HSF4 revealed three mutations: R116R, L245>L and P421>L in exon 5, 10 and 14, respectively. The coding exons for CRYAA showed two sequence variants: S134W and K166N in exon 3. Twelve mutations were identified in exon one of all three GCNT2 transcripts (A, B and C). These mutations include: G212G, H256>H, M258>V, N275>N, V16>I, Y122>F, S15>S, S24>N, S38>S, I118>I, D194>D and Y373>Y which was found in exon three of all transcripts. There were no mutations in LIM2, however, three single nucleotide polymorphisms (SNPs) were identified in exon 2 (P66>P) and 3 (I118>T and A127>T). The above mutations were conserved when aligned with other species. The sequence variations vary among the families and those individuals with the same or different cataract phenotype. Based on these findings, it can be concluded that the four candidate genes harbour mutations that are responsible for both phenotypes. The effect of these mutations in Vervet monkeys is not yet understood, however, their impact will be further investigated. For future studies, it will be of absolute importance to screen the entire family to verify that indeed cataract formation in this colony is inherited in an autosomal recessive manner.

This thesis presents the development and application of methods to assess cognitive markers of emotion and psychological wellbeing in a species of nonhuman primate, the rhesus macaque (Macaca mulatta). In humans, vulnerability to emotional disorders such as anxiety and depression is characterized by particular cognitive profiles, known as cognitive biases. For example, anxious people automatically attend to threat-relevant information, interpret ambiguous information negatively, and have negative expectations of future events. In this thesis, I first describe two treatments that were used prior to cognitive testing to induce positive and negative shifts in inferred affective state in the monkeys (enrichment and a health-check, respectively) and discuss the impact of these treatments on the monkeys’ behaviour and physiology (Chapters 2 and 3). In the first cognitive study (Chapter 4), I present a method that uses eye-gaze to assess the extent to which threatening (versus non-threatening) stimuli capture visual spatial attention when two stimuli are presented at different locations. In the second study (Chapter 5), I present a simple operant touch-screen task to assess the extent to which a threatening distractor stimulus captures attention and impairs performance on an ongoing task when presented at the same location as the taskrelevant stimulus. In the third study (Chapter 6), I present a Go/NoGo touchscreen task to assess judgements about the reward value of ambiguous stimuli. In all of these studies, the two treatments led to different cognitive profiles in the monkeys. Monkeys showed a) automatic capture of attention by threatening stimuli, which was followed by avoidance following the health-check, but not Post-enrichment; b) impaired task performance when a threatening distractor stimulus was presented Post-health-check, and improved performance on these trials Post-enrichment; and c) a more negative judgement about the reward value of ambiguous stimuli Post-health-check versus Post-enrichment. I discuss these cognitive biases in light of available data from humans, and recent work with nonhuman animals. These data indicate that furthering our understanding of primate and other animal psychological wellbeing, may be achieved through the development of measures of cognitive bias, such as those presented here.

>Magister Scientiae - MSc / Molecular genetics: strategies to indentify congenital cataract genes in captive-bred Vervet monkeys Zandisiwe Emilia Magwebu MSc thesis, Department of Medical Biosciences, University of the Western Cape The present study describes molecular aspects of inherited congenital cataract in captive-bred Vervet monkeys. Congenital cataracts are lens opacities that are present at birth or soon after birth and include hereditary cataracts or cataracts caused by infectious agents. The MRC Primate Unit is housing a colony of captive-bred Vervet monkeys in which 7.5% is suffering from congenital cataract. However, the parents of the affected individuals were asymptomatic. Six families within the colony have been identified to be affected by two types of morphologies (Ysutural and total cataract). Based on the evidence provided above, it was speculated that the colony was affected with autosomal recessive cataract. The main aim of this study was to facilitate a strategy for managing breeding programs by minimizing cataract occurrences in captive-bred Vervet monkeys. Integrated combination of clinical, molecular and bioinformatic strategies were used to identify and assess reciprocal candidate susceptibility genes for cataracts. The genes that are known to be responsible for most human congenital cataract cases were prioritized. The genes include Heat shock transcription factor 4 (HSF4), Crystalline Alpha A (CRYAA), glucosaminyl (N-acetyl) transferase 2 (GCNT2) and Lens intrinsic membrane protein 2 (LIM2). Twenty two subjects were selected based on their morphology (5 carriers, 5 controls and 12 cataracts). 2ml of blood was collected for Deoxyribonucleic acid (DNA) extraction. Coding exons and flanking regions were screened by polymerase chain reaction (PCR) amplification and sequenced. The CLC DNA workbench was used for results analysis. The screening of four genes revealed 20 sequence variants which were not present in the control individuals. Sequencing of HSF4 revealed three mutations: R116R, L245>L and P421>L in exon 5, 10 and 14, respectively. The coding exons for CRYAA showed two sequence variants: S134W and K166N in exon 3. Twelve mutations were identified in exon one of all three GCNT2 transcripts (A, B and C). These mutations include: G212G, H256>H, M258>V, N275>N, V16>I, Y122>F, S15>S, S24>N, S38>S, I118>I, D194>D and Y373>Y which was found in exon three of all transcripts. There were no mutations in LIM2, however, three single nucleotide polymorphisms (SNPs) were identified in exon 2 (P66>P) and 3 (I118>T and A127>T). The above mutations were conserved when aligned with other species. The sequence variations vary among the families and those individuals with the same or different cataract phenotype. Based on these findings, it can be concluded that the four candidate genes harbour mutations that are responsible for both phenotypes. The effect of these mutations in Vervet monkeys is not yet understood, however, their impact will be further investigated. For future studies, it will be of absolute importance to screen the entire family to verify that indeed cataract formation in this colony is inherited in an autosomal recessive manner.