ISSN:0012-1630    

DOI:10.1002/dev.420020202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractChicks hatched from eggs injected with reserpine prior to incubation showed impaired performance in detour learning between 7 and 17 days of age, although locomotor activity and brainstem catecholamine levels were not significantly different from controls at 18 days. Day‐old chicks injected with the same amount of drug showed no significant depletion of brainstem catecholamines 7 days later, supporting the possibility that behavioral effects were due to exposure to the drug during embryogenesi

ISSN:0012-1630    

DOI:10.1002/dev.420020203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractThe gross activity of wild and semi‐domestic strains of prairie deermice was measured in two kinds of novel test apparatus (tilt‐cage and activity wheel). Differences in strain activity were not obtained in either apparatus. Activity was significantly decreased in both strains by early experience in the field and by rearing wild genotype subjects in large laboratory cages. It was suggested that differential early sensory experience associated with both qualitative and quantitative aspects of the early rearing environment may be responsible for the treatment effect. Whereas no daily changes in activity were noted in the tilt‐cages, activity in the wheels was sipnificantly higher onday 1 for all groups. In contrast to recent literature, wheel running activity did not change with total water depriv

ISSN:0012-1630    

DOI:10.1002/dev.420020204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractTwo independent groups of dogs (41 cross‐sectional and 16 longitudinal) were tested either once or successively in a behavior arena at 5, 8, 12, or 16 weeks of age for exploration to novel stimuli. The stimulus situations were, respectively, an empty cage, rat in a cage, mirror, auditory click, toy puppy, and flashing light. In the cross‐sectional group at the early ages more time was spent with the rat‐in‐cage and flashing‐light stimuli than with others. No differences in exploration time to any stimuli were seen after 8 weeks. Both number of squares traversed and number of „yelps”︁ seemed to fluctuate more with increasing age. In contrast, the longitudinal group showed an increase in exploration with re‐testing. More time was spent with the toy pup and flashing light at the early ages, whereas the mirror was interacted with more at 12 and 16 weeks. Activity increased upon re‐testing, whereas vocalization decreased significantly after the first exposure to the testing arena. An evaluation of the reaction of each pup to a human was done on the day prior to testing. Those dogs that interacted with a human were also more exploratory and less fearful of a novel environment than those not interacting with a human. Results are discussed in terms of experiential rather than maturational factors as enhancing or modifying exploratory

ISSN:0012-1630    

DOI:10.1002/dev.420020205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractA sterotaxic atlas of the hypothalamus of the 1‐, 7‐, and 14‐day‐old rat is presented. Ancillary techniques for anesthetizing these young animals, mounting the neonates in the instrument, and special histological considerations are di

ISSN:0012-1630    

DOI:10.1002/dev.420020206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractNormally expected visual behavior in the cat, following monocular training, is a full stimulus equivalence when the second eye is used in transfer tests. This expectation has not been tested severely by using competing habits trained separately for each eye. Two groups of cats, normal and with striate cortex ablated, were tested under conditions of training in which opposing habits were used with the two eyes. Using intensity discrimination habits it was found that normal and operated cats failed to show complete interocular transfer. The normal group exhibited more transfer (greater conflict) from one eye to the other than did the operated group. It is suggested that interocular equivalence is partly dependent upon the organism's having learned to use similar kinds of visual cues with both eyes. The data also support the idea that encephalization increases binocularity and interocular equivalence.

ISSN:0012-1630    

DOI:10.1002/dev.420020207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractIn 2 experiments, littermate male gerbils were kept in enriched (EC), standard colony (SC), or impoverished (IC) environments from 30 to 60 days of age. Cerebral effects of these environmental treatments were compared with results obtained previously with laboratory rats and mice. The EC gerbils show, in comparsion with IC, an increase in cortical weight and an increase in the cortical/subcortical weight ratio, a decrease in cortical acetylcholinesterase per unit of weight, and a slight increase in the ratio of cholinesterase to acetylcholinesterase in the cortex. These changes for the most part follow the pattern of EC‐IC effects found in the rat and mouse. In both absolute brain measures and in EC‐IC effects, the gerbil resembles the rat more closely than the mouse. The results extend the generality of findings withinRodentiafrom the familyMuridae, which includes rats and mice, to the familyCricetidae, to which gerbils belong. Furthermore, the gerbil, unlike the laboratory rat and mouse, has not been subjected to many years of selection for laboratory conditi

ISSN:0012-1630    

DOI:10.1002/dev.420020208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractMaturation of the cerebellar influence on rubral cells was studied in70 young rabbits aged from 3 to 17 days. Extracellular spike potentials of 187 neurons belonging to the magnocellular part of the red nucleus were recorded with glass microelectrodes. The differences observed between young and old animals are quantitative and particularly striking. Out of 107 cells in animals less than 8 days old, only 7 were facilitated or inhibited by cerebellar stimulation, whereas in older animals, out of 80 cells, 76 were facilitated or inhibited. Similar results were obtained for 273 perirubral cells and 72 oculomotor cells.The present results suggest that cerebello‐interposital or interposito‐rubral connections are not yet functional during the first postnatal w

ISSN:0012-1630    

DOI:10.1002/dev.420020209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractThe development and distribution of+‐K+‐stimulated and Mg2+‐dependent ATPase activity in different parts of the chick embryo brain were investigated. Maximal changes in the Na+‐K+‐stimulated ATPase activity in the hemispheres and optic lobes took place betweenday 15and17and in the cerebellum and brain stem betweenday 17and19of incubation. Most of this activity was localized in the membranous fraction of the chick embryo brain. An attempt was made to correlate the rapid rise in the activity of this enzyme with the development of electrical properties of the chick emb

ISSN:0012-1630    

DOI:10.1002/dev.420020210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractReserpine significantly decreased the concentrations of atecholamines (CA) in the brains of 14‐ and 18‐day‐old chicken embryos when administered prior to incubation in a dose that has little or no effect upon hatchability. Administration of this drug had profound effects upon the fluorometric estimation of CA in the brains of both embryonic and newly hatched chicks. This can lead to an erroneous interpretation of the quantitative effects of reserpine on CA concentrations in the

ISSN:0012-1630    

DOI:10.1002/dev.420020211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY