摘要:

AbstractMurine spinal sensory neurons migrate in dissociated cell culture resulting in convergence, divergence and cluster rearrangement by the cells. We found that culture medium which had been conditioned by the growth of spinal cord cells stimulated the convergence of DRG cells into clusters. Binuclear sensory neurons, which are often found in these cultures, failed to migrate or proceed with mitotic cleavage during the 2 weeks of observation. We conclude that these cells were arrested in mitosis during or shortly after their removal from the 13‐day‐old embryo.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90027-8

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThis study examined effects of neonatal prochlorperazine in rats tested as adults in a variety of behaviors. The drug exposure impaired open field behavior during treatment neonatally. However, no differences in open field behavior were observed in adulthood. Adult females that had received drug were less efficient in obtaining food reinforcement in a conditioned maze performance than were respective controls and showed a slight increase in motor activity during accommodation.d‐Amphetamine‐induced motor activity was greater in both treated males and females relative to respective controls. Spaced trials in shuttle‐box avoidance uncovered an avoidance decrement in the treated females only. This drug treatment appears to cause subtle changes in brain development in the rat.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90028-X

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractGlucose consumption of skeletal muscle differentiatedin vitrowas studied under various experimental conditions by means of the [3H]deoxyglucose ([3H]DG) uptake technique. The results show that glucose uptake by skeletal muscle is a function of its activity; when the muscle is electrically stimulated to contract the uptake of [3H]DG is increased, and when spontaneous activity is inhibited, the uptake of [3H]DG is decreased. While electrical stimulation (ES) did not affect the uptake of 3‐O‐methyl‐glucose (3‐OMG), DG uptake was enhanced in spite of the presence of cycloheximide in electrically stimulated cultures, suggesting that muscle contraction probably activates the enzyme hexokinase. Thus our data show that the uptake of [3H]DG can be a tool for measuring muscle contraction.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90029-1

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractOlfactory neuroepithelium of neonatal rat pups has been transplanted in the anterior chamber of the eye of adult rats. Structural and ultrastructural observations at 5, 10, 30, 50, 90 and 120 days show that mature neurons degenerate rapidly in the expiant (before 5 days) while the basal elements proliferate and produce a new population of young neurons between 1 and 10 days. At longer survivals (30–120 days) it is seen that the neurons acquire morphological maturity, and positivity to the olfactory marker protein, as demonstrated by immunohistochemical methods. Our observations show that new neurons can be generated in the transplanted neuroepithelium and that their generation and maturation occurs in the absence of connections with a brain target.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90030-8

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe postnatal development of the cholinergic neurotransmitter system was studied in the cortex, hippocampus, midbrain and cerebellum of 3‐, 7‐, 12‐, 17‐ and 30‐day‐old NMRI mice. The concentration of muscarine‐like binding sites determined with [3H]quinuclidinyl benzilate as a ligand increased progressively with age. A similar developmental pattern was found for the activity of a presynaptic marker, choline acetyltransferase (ChAT). When expressed as a percentage of the values for 30‐day‐old mice, however, the muscarine‐like receptors were parallel but preceding the development of ChAT in all the brain regions studied. The concentration of nicotine‐like binding sites studied with [3H]α‐bungaro‐toxin as a ligand gradually increased with age in the cortex, hippocampus and midbrain, with a peak between days 7 and 12, followed by a decrease towards day 30. With [3H]tubocurarine as a ligand, on the other hand, the concentration of nicotine‐like binding sites was in general high at 3 days and gradually decreased with age, suggesting that different subpopulations of nicotine‐like receptors might be determined when the two ligands are used.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90031-X

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractSpecific inhibition of ornithine decarboxylase selectively in the developing rat cerebellum was achieved within 10 min after intrathecal injection of α‐difluoromethylornithine. Twelve hours later the activity started to increase, passed control levels between 2 and 3 days, continued to increase and reached its peak values by day 3 (when animals were 10 days old), 3 days after peak control values. Ornithine decarboxylase activity then declined and attained low adult values simultaneously with controls. Glutamic acid decarboxylase activity, a marker of gabaergic neurons maturation, declined to a nadir at 3 days postinjection, and then was elevated transiently above control levels with a peak at 11 days postinjection. We conclude that after such a temporary insult neuroblasts of the cerebellar cortex are capable of full recovery, which is apparent by a reversible reduction in ornithine decarboxylase and glutamic acid decarboxylase activities followed by a transient compensatory elevation in both enzymes.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90032-1

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractDeveloping nigrostriatal neuroblasts exhibit catecholamine‐induced fluorescence before their axons have left the vicinity of the cell bodies. To evaluate possible developmental effects of dopamine, we have used reserpine andα‐methyl‐p‐tyrosine to deplete dopamine chronically during the development of these axons. We found that dopamine‐induced fluorescence was either absent or markedly decreased in the fetal putamens. To determine whether the absence of fluorescence was due to a reduction of dopamine terminals, the uptake of tritium‐labeled dopamine was measured in the putamen. Uptake of labeled dopamine was significantly depressed in reserpine‐treated fetuses to 70% of that of controls; however, no depression of labeled dopamine was found in theα‐methyl‐p‐tyrosine‐treated fetuses. After both drug treatments, the striatal perikarya were less mature than those of controls. Although we cannot rule out possible non‐specific or toxic effects of the drugs, these observations support the conclusion that presynaptic dopamine may be important for development of target neurons in the neostriatum.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90033-3

出版商:Wiley    

年代:2003

数据来源: WILEY

摘要:

AbstractThe whisker pattern on the muzzle of the mouse is mapped in the contralateral parietal neocortex, each whisker follicle projecting to its own multineuronal unit (‘barrel’). To determine the role, if any, of the peripheral innervation in the establishment of the vibrissal array, we cultured non‐innervated prospective whiskerpads from 9‐ and 10‐day‐old embryos, mostly on chorioallantoic membrane. The results show that skin, alone, is capable of generating the whisker pattern, thus adducing a strong argument for the hypothesis that the central brain maps have their origin in the periphery.

ISSN:0736-5748    

DOI:10.1016/0736-5748(83)90034-5

出版商:Wiley    

年代:2003

数据来源: WILEY