ISSN:0006-8977    

DOI:10.1159/000114175

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000114176

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000114177

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000114178

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Based on retrograde labeling from the high cervical spinal cord, the inter- and intra-laminar distributions of tectospinal tract (TST) somata within the tectum of 23 mammals and one reptile are described. The results show that TST somata are found only in the intermediate and deep layers. Although more TST somata are usually found in the intermediate layer, there are no useful relationships for predicting the number in one layer given the number in the other. The ratio of numbers of TST somata in the intermediate relative to the deep layer varies widely, from 0:1 (in rabbits) to over 8:1 (in marmosets). Within both layers the majority of TST somata (>80%) are found in the lateral half of the tectum – the area subversing the lower visual field. In contrast, the variation between temporal and nasal visual fields is adequately accounted for by the animal's 'visual axis' – the azimuth of its field of best vision. In general, the present results uphold the idea that the significance of the TST somata, and perhaps of the tectospinal tract itself, is to be found in directing the head so that the retinal area of best vision can be brought to bear on stimuli either almost outside, or about to pass outside, of the area of best vision. The larger and possibly universal predominance of TST somata subserving the lower visual field suggests that the tectospinal tract may be primarily concerned with adjusting the step dimensions of the forelegs to accommodate obstacles to normal progression.

ISSN:0006-8977    

DOI:10.1159/000316115

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000316222

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Seven hypothalamic nuclei and several isolated perikarya that send projections to the pituitary gland were identified following administration of cobaltous lysine or horseradish peroxidase (HRP) to severed hypophysial stalks of previously hypophysectomized catfish, Clarias batrachus. Retrogradely labelled neurons were identified in the nucleus preopticus periventricularis, suprachiasmatic nucleus, paraventricular and supraoptic divisions of the magnocellular nucleus preopticus (NPO) and nucleus lateralis tuberis. A few neurons in the paraventricular subdivision of the NPO, however, remained unfilled; these may project to extrahypophysial sites. Three other nuclei contributing to the innervation of the pituitary gland include the paraventricular organ, nucleus recessus lateralis (NRL) and nucleus recessus posterioris (NRP), all of which contain cerebrospinal fluid-contacting aminergic neurons. These three neuronal aggregations were retrogradely labelled with cobaltous lysine but not with HRP. Isolated neurons displaying hypophysial connections were identified in the organon vasculosum laminae terminalis area, in the nucleus hypothalamics ventromedialis, and in the vicinity of the NRL and NRP. Thus the present study reveals that hypothalamic projections to the pituitary gland of catfish have their origin in several peptidergic and aminergic nuclei and perikarya hitherto unreported.

ISSN:0006-8977    

DOI:10.1159/000114138

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000114179

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Behavioral ratings on several affective scales (non-erotic/erotic, unpleasant/ pleasant, simple/complex and low arousal/high arousal), and electrophysiological responses (event-related brain potentials) to emotional pictures, were collected from 30 female subjects, at different phases of their menstrual cycle. The pictures belonged to 5 emotional categories, whose content was babies, dermatological cases, ordinary people, male models and female models. The subjects were grouped into hormone defined phases, according to their expected levels of androgens, estrogen or progesterone. The data were analyzed to determine if emotional or cognitive processing was sensitive to the reproductive status, as indicated by menstrual phase. Only one component of event-related potentials, the P3 component, varied with menstrual phase. Baby and male model pictures elicited larger P3 waves when progesterone level was high. High progesterone was also associated with a decrease in complexity and eroticism to all picture categories. An increase in the pleasantness of all categories was evident when estrogen levels were high. The results are interpreted as support for a general proximal design, whereby emotional and cognitive processes are adaptively regulated by reproductive status.

ISSN:0006-8977    

DOI:10.1159/000114139

出版商:S. Karger AG    

年代:1993

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000114180

出版商:S. Karger AG    

年代:1993

数据来源: Karger