Nervous system

About: Nervous system is a research topic. Over the lifetime, 16729 publications have been published within this topic receiving 847181 citations.

Behavioral effects of some psychopharmacological agents.

Abstract: Behavioral responses developed in rats have been employed in the evaluation of the comparative effects of several central nervous system (CNS) active pharmacological agents. Differentiation has been made between those CNS active materials that have a specific effect on a conditioned response (chlorpromazine, reserpine, morphine), and those that have a somewhat nonspecific effect on a conditioned response (barbital, pentobarbital, methylparafynol, meprobamate). The interrelationships between reserpine and serotonin in the CNS have been described by Pletscher et al.’ The effect of serotonin itself upon a conditioned response has also been examined in this study. Lysergic acid diethylamide (LSD) has been reported to antagonize certain properties of serotonin (Gaddum,2 Shore et ~ l . , ~ Costa4) and reserpine (Shore et ~ 1 . ~ ) . We have utilized the conditioned response to examine the interactions of lysergic acid diethylamide with reserpine and serotonin, as well as chlorpromazine, morphine, and meprobamate. Mescaline was also studied, in a manner similar to LSD-25, for possible interaction with conditioned-response blocking agents.

Common origin and developmental dependence on c-ret of subsets of enteric and sympathetic neuroblasts.

Abstract: c-ret encodes a tyrosine kinase receptor that is necessary for normal development of the mammalian enteric nervous system. Germline mutations in c-ret lead to congenital megacolon in humans, while a loss-of-function allele (ret.k-) causes intestinal aganglionosis in mice. Here we examine in detail the function of c-ret during neurogenesis, as well as the lineage relationships among cell populations in the enteric nervous system and the sympathetic nervous system that are dependent on c-ret function. We report that, while the intestine of newborn ret.k- mice is devoid of enteric ganglia, the esophagus and stomach are only partially affected; furthermore, the superior cervical ganglion is absent, while more posterior sympathetic ganglia and the adrenal medulla are unaffected. Analysis of mutant embryos shows that the superior cervical ganglion anlage is present at E10.5, but absent by E12.5, suggesting that c-ret is required for the survival or proliferation of sympathetic neuroblasts. In situ hybridization studies, as well as direct labelling of cells with DiI, indicate that a common pool of neural crest cells derived from the postotic hindbrain normally gives rise to most of the enteric nervous system and the superior cervical ganglion, and is uniquely dependent on c-ret function for normal development. We term this the sympathoenteric lineage. In contrast, a distinct sympathoadrenal lineage derived from trunk neural crest forms the more posterior sympathetic ganglia, and also contributes to the foregut enteric nervous system. Overall, our studies reveal previously unknown complexities of cell lineage and genetic control mechanisms in the developing mammalian peripheral nervous system.

Initial expression of neurofilaments and vimentin in the central and peripheral nervous system of the mouse embryo in vivo.

Abstract: The appearance of neurofilaments (NFs) and vimentin (Vim) in the nervous system of the mouse embryo was documented using immunohistochemical techniques. The three NF protein subunits appear early and simultaneously in central and peripheral neurons at 9 to 10 days of gestation. The onset of NF expression is concomitant with axon elongation and correlates extremely well with neurofibrillar differentiation and, in the case of autonomic ganglia, with the expression of adrenergic neurotransmitter properties. In the central and peripheral nervous system, NF expression is preceded by that of Vim, and both types of intermediate filaments coexist within the same cell for a short period of time.