Orbital Mechanics John E. Prussing caidhal
Category:Spaceflight booksSerotonergic projection from the basolateral amygdala: observations in the rat. The present experiments examine the influence of several serotonin receptor subtypes on the excitatory and inhibitory effects of serotonin (5-HT) on basolateral amygdala (BLA) neurons. In the majority of cases, 5-HT excites BLA neurons when bath applied or applied iontophoretically via a micropipette. Pre-treatment with the selective 5-HT1A receptor antagonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) increases the number of BLA neurons excited by bath applied 5-HT. Intra-BLA injection of 8-OH-DPAT is also effective in this regard. However, 8-OH-DPAT does not antagonize the majority of 5-HT inhibitory responses. The 5-HT2 antagonist ketanserin, which has a low affinity for 5-HT2A/C receptors, has little effect on the excitatory actions of 5-HT. In contrast, the 5-HT2 antagonist metitepin is an effective antagonist of the excitatory actions of 5-HT on BLA neurons. The 5-HT2 antagonist spiperone is effective at antagonizing the inhibitory actions of 5-HT on BLA neurons. The 5-HT3 receptor antagonist, MDL72222, is ineffective in this regard. However, iontophoretic application of MDL72222 blocks the excitatory actions of bath applied 5-HT on BLA neurons. Taken together, the results suggest that 5-HT excites BLA neurons via 5-HT1A receptors, whereas the inhibitory effects of 5-HT are mediated via 5-HT2/5-HT3 receptors.Telocyte characteristics based on ultrastructure and immunohistochemistry. It is well-established that vascular cells (EC and SMC) interact and organize themselves in complex networks (vasculature), and non-vascular cells, including mesenchymal stem cells (MSC), fibroblasts and endothelial cells, have been demonstrated to interact. This chapter reviews the available data on the ultrastructural and immunohistochemical characteristics of telocytes and their subpopulations, namely telocytes with dendritic processes and telocytes with a chunky-looking cytoplasm.