A novel hinge system and incubation chamber for emulsion-coated coverslip autoradiography.

We describe an emulsion-coated coverslip autoradiographic technique for large (50 x 50 mm) sections of monkey or human brain. The technique uses adhesive-backed, teflon-reinforced aluminum foil as a flexible hinge that allows the coverslip to swing away from the slide so that the emulsion and tissue can be processed independently. We also describe a plexiglas incubation chamber that allows two slides with coverslips folded away to be processed back-to-back in 5 ml of reagent solution. In general use, the chamber minimizes the volume of solution needed to cover large slide-mounted sections and is ideal for radioligand or immunohistochemical reactions that use expensive reagents. For autoradiography, the chamber greatly facilitates independent processing of the emulsion and tissue section. Together, the foil-hinge method and incubation chamber virtually eliminate the major technical pitfalls of previous emulsion-coated coverslip methods. Moreover, they facilitate combination of histochemical or immunocytochemical staining with autoradiographic localization of neurotransmitter receptors in the same tissue section. This is demonstrated by thioflavin S staining of neuritic plaques and tangles and autoradiographic localization of serotonin 1A receptors in sections of Alzheimer disease brain.

A regulatory role in mammalian salivary glands for 5-hydroxytryptamine receptors coupled to increased cyclic AMP production.

Although a functional role for serotonin (5-hydroxytryptamine, 5-HT) has been defined in the salivary glands of some lower species, relatively few data supporting a role for 5-HT in the regulation of mammalian salivary glands have been presented. Our initial results from polymerase chain reaction studies in cells of mammalian submandibular gland origin using consensus sequence primers from G protein-coupled receptors suggested the presence of mRNA for a 5-HT receptor in these cells. Based on this observation, the question of a role for 5-HT in mammalian submandibular gland function was re-addressed, using isolated, perfused rat submandibular glands and dispersed-cell aggregates from this gland. In perfused glands, 5-HT decreased the rate of saliva flow initiated by acetylcholine by about 50% and increased the amount of protein in the saliva two-fold. In dispersed-cell aggregates, 5-HT elicited a concentration-dependent increase in the accumulation of adenosine 3',5' monophosphate (cyclic AMP; EC50 = 660 +/- 110 nM). In addition, functional studies, as well as radioligand binding experiments, indicated that the effects of 5-HT are independent of beta-adrenoceptors. Accumulation of cAMP in gland cells was consistent with a direct action of 5-HT on adenylyl cyclase. Similar cyclic AMP responses to 5-HT were observed in cells isolated from mouse and opossum submandibular glands and rat sublingual and parotid glands. Our findings suggest the presence of a 5-HT receptor in mammalian salivary glands coupled to the stimulation of adenylyl cyclase and, at least in rat submandibular gland, involved in modifying the volume and protein content of saliva.

[The effect of bromantane on the dopamin- and serotoninergic systems of the rat brain]. / Vliianie bromantana na dofamin- i serotoninergicheskie sistemy mozga krys.

The effect of acute and chronic administration (50 mg/kg, p.o.) of a new immunostimulator, bromantan exhibiting psychostimulant features on the content of NE, DA and 5-HT, and their metabolites are studied. Bromantan induced a significant increase in the 5-HT and 5-HIAA content in the frontal cortex and delayed an increase in their content in subcortical brain regions. A stable decrease in the 5-HT and 5-HIAA levels in the cerebellum is observed. The drug also affected the DA parameters of the brain thus suggesting an important role of dopaminergic system in the mechanism of pharmacological effects of the drug.