摘要:

In mammals the fibers of the dorsal lateral olfactory tract either pass under the accessory olfactory formation, or they penetrate through it separating the internal granule cells from the output cells. The use of this trait as a phylogenetic indicator in 181 specimens representing 131 species of 16 orders yielded evidence for common ancestry of Insectivora, Chiroptera, Dermoptera, Rodentia, and Primates (including Tupaia), since all share the derived trait, their dorsal lateral olfactory tract fibers passing through the accessory olfactory formation. Carnivora (including Pinnipedia), Hyracoidea, Perissodactyla, and most Artiodactyla share the primitive condition (fibers passing under) with the one order of monotremes and three marsupial orders. The Edentata and Lagomorpha may be separate from the two major placental groups and from each other, or they may represent successive stages in the evolution of the derived state through progressive alterations in the relative chronology of development of olfactory system components, or one or both orders may occupy an ancestral position with respect to the dichotomy within placental mammals.

ISSN:0006-8977    

DOI:10.1159/000121808

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

Axon collateralization appears to represent a prominent feature of the mammalian visual system. Both anatomical and electrophysiological evidence reveal that axon branching occurs in the retinofugal, geniculocortical and visual corticifugal projections. Most of this evidence is provided by studies on the cat, but enough data are available from investigations on the rat and monkey to permit certain interspecies differences to be recognized and evaluated. Axon branching allows individual axons to provide innervation to two or more targets and generally to transmit the same type of visual information to these targets. There is abundant evidence to suggest that two of the three functional classes of retinal ganglion cells and geniculate relay cells (namely Y and W ganglion and relay cells) utilize axon branching; however, few details regarding this subject are currently available. The third functional class of ganglion and relay cells (X ganglion and relay cells) essentially lacks axon branches.This review has three primary goals: (1) to review the pertinent anatomical and electrophysiological literature dealing with axon branching and to discuss areas in which information is meager and further investigation necessary; (2) to emphasize the need for applying recently developed techniques, such as double-labeling of neurons and electrical collision, to the study of axon collateralization, and (3) to formulate some hypotheses concerning the functional significance of axon branching.

ISSN:0006-8977    

DOI:10.1159/000121809

出版商:S. Karger AG    

年代:1980

数据来源: Karger

摘要:

In an established social group of rhesus monkeys (Macaca mulatta) consisting of 1 adult male, 6 adult females, 1 adolescent male and 2 infants, 3 subjects were selected to study the effects of intramuscular methaqualone (10 mg/kg) on behavioral changes in the treated animals, as well as the rest of the colony. Three drug trials alternating with saline controls were given to the dominant male, a mid-ranking female and the adolescent male. 20 h of observations were made prior to treatment to serve as a baseline, using 40 discrete behaviors. For each drug and saline period, 2h of continuous observation was directed towards each target animal (total 36 h), and 12-min behavioral samplings were carried out on each untreated subject in the colony (36 h). Dependent upon the sex and social rank of the subject, different behavioral changes occurred during drug treatment, which were consistent from trial to trial.New behaviors were observed, such as active grooming, autofellatio and masturbation in both males, while some previous behaviors disappeared or decreased. The mid-ranking female showed an increase in aggressive behavior. A biphasic action of the drug was also observed in all subjects. During the first 80–100 min, the males were mainly passive or engaged in grooming, but after this primary phase, they started either to masturbate or autofellate. After approximately 2 h, the social status and behavior of the animals returned to predrug levels. During the drug treatment, marked changes occurred in the behavior of other colony members, e.g. when the dominant male''s vigilance was lowered, the highest ranking female replaced him in rank.In general, affiliative activities were increased under the influence of methaqualone, manifesting themselves mainly in grooming, huddling or sitting together: phenomena somewhat parallel to those described among humans taking the drug in group setting

ISSN:0006-8977    

DOI:10.1159/000121810

出版商:S. Karger AG    

年代:1980

数据来源: Karger