Arthur Kling

Uncus and Amiygdala Lesions: Effects on Social Behavior in the Free-Ranging Rhesus Monkey

The eflect of uncinectomny on the social behavior of free-ranging rhesus monkeys was observed on Cayo Santiago Island. Operated subjects showed social indifjerence, failed to display appropriate aggressive and submissive gestures. were expelled from their social group, and evenitlually died. Two juvenile subjects with the lesion restricted to amygdala survived and have rejoinied their social group. Size of lesion and age at operation were major factors in determniting the degree of behavioral change.

Differential effects of early and late lesions of frontal granular cortex in the monkey

Summary Bilateral ablations of dorsolateral frontal granular cortex were performed in four monkeys prior to the 35th postnatal day and in three monkeys at 3 years of age. Subsequent testing procedures involved the learning of a color discrimination, a series of delayed response tests and a delayed alternation task. No differences were found between early- and late-frontals in learning the color problem. All animals were equally impaired in delayed alternation performance. Delayed response testing revealed a marked superiority for early-frontals, relative to the performances of later-frontals. Differential delayed response performances of the two frontal groups were not due to differences in either surface lesion or retrograde thalamic degeneration. It was concluded that either a compensatory neural reorganization or a progressive cerebral maturation might account for the sparing of delayed response capacity in the early frontal preparations.

AMYGDALECTOMY IN THE FREE-RANGING VERVET (CERCOPITHECUS AETHIOPS)"

environment. Recent field studies of the social behavior of a variety of subhuman primates have emphasized the rich repertoire of social interactions and their adaptive significance for the species.l-3 These studies have also emphasized the differences in individual as well as social behavior that exists between species of primates. However, these differences have generally not been an important consideration in assessing the behavioral changes occurring from experimental brain injury. Therefore, a series of experiments have been planned to study the effects of brain lesions on social behavior both in the laboratory and in the field in several species of Old-World monkeys. Eventually, it may be possible to define more clearly those aspects of a syndrome which are species specific, as well as other aspects which are characteristic of most subhuman primates. Comparison of the behavioral changes seen in the field with those observed in the laboratory may help to clarify the influence of caging and to make laboratory observations more pertinent. For the present experiment we chose to ablate the amygdaloid nuc1ei.S Under laboratory conditions, bilateral lesions of the amygdaloid nuclei in the individually caged, adult rhesus monkey (M. mulutta) results in a syndrome of relative docility, especially toward man, hyperorality, coprophagia and hypersexuality.4 Two studies have examined the effects of amygdalectomy on social interaction in groups of laboratory housed macaques. ROSVOLD, MIRSKY and PRIBRAM~ have reported that

Social Behavior of Monkeys Selectively Depleted of Monoamines

Initiated social interactions of Macaca speciosa are decreased during the period of treatment with alpha-methyl-p-tyrosine, an inhibitor of catecholamine synthesis. The treated animals maintained stable body weights and appeared to be healthy. Similar depletion of indoleamines with p-chlorophenylalanine does not change these same observed behaviors in spite of weight loss, hair loss, ataxia, and debilitation in some of the animals.

Amygdalectomy in the Kitten

Kittens sustaining bilateral amygdalectomy failed to show behavioral changes seen in the adult after subjection to similar lesions. No growth deficits or hypopituitarism occurred in the kittens. A certain level of neuroendocrine maturation may be necessary for the effects of amygdalectomy to be manifested.

Effects of combined lesions of frontal granular cortex and caudate nucleus in the neonatal monkey

Abstract Combined bilateral lesions of frontal granular cortex and caudate nucleus were produced in 7 monkeys between the 2nd and 56th postnatal day. When comparisons were made with 4 monkeys which had previously sustained bilateral resections of frontal granular cortex alone at comparable ages, it was found that the frontal-caudates, in contrast to the frontals, displayed failure to thrive, somato-motor and growth deficiencies, postoperative seizures and later cognitive impairments. When tested at the 7th postoperative month, 2 of the 3 surviving frontal-caudates could not perform a delayed response task beyond a minimal (0 sec) delay interval. It was concluded that early reflexive and somato-motor function is principally mediated by subcortical systems but that some degree of representation also exists at cortical levels. In contrast to neocortex, the caudate nucleus appears to be involved in a neural system responsible for the retention of delayed response capacity following early brain injury.

The Stump-Tailed Macaque: A Promising Laboratory Primate

Members of Macaca speciosa have characteristics that make them suitable primates for neuropsychological investigation. They work well in discrimination training, have a varied behavioral repertoire and social interaction, and seem to be at least as intelligent as M. mulatta. They are docile and submit readily to laboratory routine.

Polycythemia of stress in psychiatric hospital populations.

Abstract The admitting hemoglobin and hematocrit of 226 male patients in 3 Chicago hospitals was compared to the same values for 128 male graduate students and employees of the same institutions. Know current medical disorders were considered reason for exclusion from the study. The criteria for polycythemia of stress was both hemoglobin in the range of 16–18 g.% and hematocrit in the range of 50–56 per cent. The patient population showed an incidence of 19⋯0 per cent cases copared to 7 per cent for the controls (p The results were felt to confirm the association of chronic emotional stress with moderate elevations of hemoglobin and hematocrit.

Preservation of delayed response following combined lesions of prefrontal and posterior association cortex in infant monkeys

Abstract The preservation of delayed response capacity in monkeys sustaining bilateral ablations of prefrontal cortex in infancy has been attributed to the intactness of the caudate nucleus, since combined prefrontal-caudate lesions in infant monkeys produce severe delayed response deficits at later testing. However, before concluding that the integrity of the caudate is essential, it must be shown that another type of combined lesion sustained in infancy is without substantial effect on later test performance. Since bilateral ablations of parieto-temporo-preoccipital (posterior association) cortex in adult monkeys are known to produce delayed-response deficits, a combined prefrontal-posterior association cortex lesion was judged to be the appropriate control. Accordingly, three infant monkeys were subjected to two-stage bilateral ablations of prefrontal and posterior association cortex prior to postnatal day 18. Testing on a series of delayed response problems was initiated between the eighth and tenth postnatal months. Test performances were found to be essentially equivalent to those of animals sustaining only a prefrontal ablation in infancy. In one preparation, a transient delayed response deficit during initial testing was attributed to minor caudate involvement. Although subtotal ablations in posterior association cortex were found in all cases, the massive lesions that were sustained make it unlikely that this area is functionally involved in preserving delayed response capacity in the early lesioned prefrontal monkey. These results tend to confirm our previous conclusion as to the functional importance of the caudate nucleus, possibly via its capacity to regulate locomotion and attention.

Plasma levels of 17-hydroxycorticosteroids during sexual arousal in man ☆

IT IS now well established that plasma levels of 17-hydroxycorticosteroid (17-OHCS) may be used as an indicator of emotional arousal. Investigations into the relationship between a variety of psychological states and changes in 17-OHCS levels have largely been concerned with such emotions as anger, anxiety, fear, coping ability, depression and stressful life situations [l]. In general, these studies conclude that these emotional states are accompanied by increase in plasma 17-OHCS levels. In an exhaustive review, Mason [2] concluded that elevations of 17-OHCS are not related to any specific affective state but “reflect a relatively undifferentiated state of emotional arousal or involvement, perhaps in anticipation of activity or coping”. Novelty, and disorganizing emotional reactions have been found to be particularly effective stimuli. In the same review, Mason suggests however, that there have been no studies dealing directly with pleasurable arousal states and 17OHCS levels. As part of a larger study concerned with the effects of sexually arousing visual stimuli in man, we have studied plasma levels 17-OHCS as one of several physiological concomitants of sexual arousal. An initial study on the effects of an erotic movie on sleep and dreams has been published earlier [3]. Subsequently, 3 additional studies using different groups of subjects have been done. In each study, blood samples were drawn for determination of the individuals plasma 17-OHCS response to the erotic films. Since it has also been well established that there is considerable variation between subjects [2] our attempt was not to study groups as such, but individuals, each exhibiting a unique life history, defensive structure, sexual interests and with differing values of what constitutes erotically stimulating material. The major question posed by this investigation is the effect of sexual arousal on the plasma levels of 17-OHCS. Since sexual arousal is an emotional state which probably has a neuro-anatomical substrate distinct from those emotional states of fear, anger and anxiety than we might expect it to also have a different influence on the hypothalamic-pituitary-adrenal cortical response.