Search PubMed⌕ Search

Biomedical subjects

O Johansson

Publications and source records attributed to O Johansson.

At least 163 records · Page 9Linked to original sources
PubMed1983

NADPH-diaphorase: a selective histochemical marker for striatal neurons containing both somatostatin- and avian pancreatic polypeptide (APP)-like immunoreactivities.

Certain neurons in the brain are specifically and intensely stained by a histochemical method which demonstrates nicotinamide adenine dinucleotide phosphate NADPH-diaphorase activity. The cell types containing this enzyme in certain areas of the rat forebrain were examined by combining NADPH-diaphorase histochemistry with the indirect immunofluorescence technique. Neurons containing somatostatin- or avian pancreatic polypeptide (APP)-like immunoreactivities were found throughout the forebrain including the striatum and neocortex. These two neuropeptides were also found to coexist in many telencephalic neurons. After photography, the sections processed for immunohistochemistry were stained for NADPH-diaphorase activity by a histochemical method. It was found that within the striatum all of the neurons that were selectively stained by this technique also contained both somatostatin- and APP-like immunoreactivities. Also in the neocortex NADPH-diaphorase was found only in those neurons displaying somatostatin- or APP-like immunoreactivity. In other brain regions such as the nucleus laterodorsalis tegmenti, NADPH-diaphorase-containing cells did not contain these neuropeptides. The results indicate that NADPH-diaphorase histochemistry provides a simple, reliable, histochemical method to demonstrate those striatal neurons in which somatostatin- and APP-like immunoreactivities coexist. The selective occurrence of this enzyme within these neurons may provide a useful target for pharmacological studies of these neuropeptide-containing cells.

Animals↗
PubMed1983

Striatal neurons containing both somatostatin- and avian pancreatic polypeptide (APP)-like immunoreactivities and NADPH-diaphorase activity: a light and electron microscopic study.

Striatal neurons containing both somatostatin- and avian pancreatic polypeptide (APP)-like immunoreactivities have been shown to be selectively stained by the histochemical method for nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase activity. In the present study, we have utilized this histochemical technique to examine the morphology of these striatal neurons at the light and electron microscopic levels. Our results indicate that the striatal somatostatin/APP/NADPH-diaphorase neurons occur throughout the striatum and have long, aspiny dendrites, oval, invaginated nuclei with prominent nucleoli, and receive few axosomatic contacts. These cells appear to correspond to a population of medium-sized aspiny interneurons reported previously in Golgi and electron microscopic studies of the striatum.

Animals↗
PubMed1983

Localization of vasoactive intestinal polypeptide- and avian pancreatic polypeptide-like immunoreactivity in the Golgi apparatus of peripheral neurons.

Using the indirect immunofluorescence technique of Coons and collaborators, vasoactive intestinal polypeptide (VIP)-like immunoreactivity (VIP-LI) and avian pancreatic polypeptide (APP)-like immunoreactivity (APP-LI) was observed in certain neurons of the peripheral nervous system of the cat. In the cell bodies in the cat sympathetic ganglia a strong to very strong VIP-LI or APP-LI was observed with a distribution resembling that of the Golgi apparatus. In addition, a weaker immunoreactivity was seen diffusely in the cytoplasm. After photography, the sections processed for immunohistochemistry were stained with the thiamine pyrophosphatase technique of Novikoff and Goldfischer. The latter technique is assumed to be a specific marker for the Golgi complex. In all cases it was found that the strong peptide immunoreactivity and the thiamine pyrophosphatase activity had an identical distribution. Thus, one pool of these peptides appears to be localized to the Golgi apparatus. Yet another pool is localized to other components, such as vesicles.

Animals↗
PubMed1983

The Vibratome-Ralph knife combination: a useful tool for immunohistochemistry.

A modified immunohistochemical technique is described for the improved detection of antigens. The method involves the use of the Vibratome combined with Ralph knives, which are easily manufactured with an LKB 2078 Histoknifemaker. The sectioning procedure was used with the peroxidase-antiperoxidase method of Sternberger and his collaborators for demonstrating growth hormone release-inhibiting hormone (somatostatin) and noradrenaline N-methyltransferase in neurones in the central nervous system of the rat. The morphological preservation of the tissue was good and cytological details were easily seen, especially in the thin sections (5-10 microns thick).

Animals↗
PubMed1983

Enhancement of immunoperoxidase staining using osmium tetroxide.

A modification of the peroxidase-antiperoxidase immunohistochemical method involving the use of OsO4 for the visualization of antigens in tissue using thick sections is described. This modification has lead to consistent enhancement of the intensity of the reaction product and thus to a further amplification of sensitivity in this particular system. The present procedure results in a sensitive demonstration of neuronal antigens such as peptides and synthesizing enzymes in neurons. The method allows the investigator to analyze the cytoarchitecture and geometry of these neurons and their projections in the nervous system as well as more easily detect single, weakly stained nerve fibers. In 50 micrometers sections, immunopositive processes can be followed over long distances. In the present study, the catecholamine-synthesizing enzyme, phenylethanolamine-N-methyltransferase (PNMT), and the neuropeptide, somatostatin, have been used as examples from the central nervous system of the rat, but the procedure is applicable to other antigens as well as other cell types and tissues.

Animals↗
PubMed1983

Opposite effects of carbohydrate and protein on phenytoin absorption in man.

Food intake has been found to enhance the absorption of phenytoin, as judged from single-dose studies in healthy volunteers taking phenytoin (acid) with and without a standardized breakfast of 1,840 kJ. In order to investigate whether this effect was due to food intake as such or to the ingestion of a certain nutrient, the influence of carbohydrate, fat, and protein, respectively, on phenytoin (acid) absorption was examined in ten healthy volunteers. The nutrients were given separately in amounts corresponding to those of the standardized breakfast previously employed. Phenytoin concentrations in plasma were measured by high-pressure liquid chromatography. The results indicate that, while fat had no measurable influence, carbohydrate may enhance, and protein reduce, the absorption of phenytoin.

Adult↗
PubMed1982

Distribution of substance P in brain and periphery and its possible role as a co-transmitter.

Substance P is widely distributed in the nervous system. In brain and spinal cord it may act as a transmitter, for example at the central branches of primary sensory neurons. It may also be released from the sensory nerve endings and is thought to be involved in antidromic vasodilatation and in synaptic transmission in autonomic ganglia. In some central neurons substance P is stored together with 5-hydroxytryptamine and thyrotropin-releasing hormone. These neurons project to the ventral horn of the spinal cord, amongst other places. In another system substance P coexists with a cholecystokinin-like peptide. These neurons are localized in the periaqueductal central grey matter and also project to the spinal cord. Finally, injection of a substance P antagonist into the ventral mesencephalon causes marked morphological changes in neurons that contain dopamine, substance P and gamma-aminobutyric acid (GABA).

Animals↗
PubMed1982

Coexistence of somatostatin- and avian pancreatic polypeptide (APP)-like immunoreactivity in some forebrain neurons.

The indirect immunofluorescence technique was used to demonstrate the coexistence of somatostatin together with avian pancreatic polypeptide-like immunoreactivity within certain neurons of the rat forebrain. Numerous neurons containing these peptides were observed in the neocortex, hippocampus, olfactory tubercle, striatum, nucleus accumbens and lateral septum. In studies of serial sections stained alternately for these two peptides, and in restaining experiments, It could be determined that in many neurons in these areas these two peptides coexisted. In other brain areas such as the anterior periventricular hypothalamus, somatostatin cells were never found to contain avian pancreatic polypeptide-like immunoreactivity. Also, within the pancreas these two peptides were never found to coexist in the same cells. The findings represent a further example of the coexistence of more than one neuropeptide within a single neuron.

Animals↗
PubMed1981

Immunohistochemical identification of two types of dopamine neuron in the rat olfactory bulb as seen by serial sectioning.

Several neurons around the glomeruli in the rat olfactory bulb contain the enzyme tyrosine hydroxylase as revealed by light and electron microscopic immunohistochemistry. Electron microscopic analysis of serial sections reveal that both superficial tufted cells and small periglomerular neurons were labelled. These results give further support for the view that dopamine neurons in the rat olfactory bulb, from a neuroanatomical point of view, do not represent a homogeneous cell population. Furthermore, taken together with previous results in the literature our findings indicate that, from a transmitter histochemical point of view, neither tufted cells nor periglomerular neurons represent a homogeneous cell population.

Animals↗
PubMed1980

Cellular localization of peptides in neural structures.

By means of the immunohistochemical technique of Coons and collaborators, numerous peptide-containing neurons have been observed in the brain, spinal cord and periphery. These neurons may contain peptides such as substance P, vasoactive intestinal polypeptide (VIP), enkephalin or somatostatin. Some systems are very extensive. For example, immunoreactive substance P has been observed in more than 30 cell groups in the central nervous system, in primary sensory neurons, in sensory neurons in the vagus nerve and in taste buds, and in intestinal neurons. Thus, one and the same peptide can be utilized at many different levels in the nervous system. Several examples are now known where a regulatory peptide occurs together with a classical transmitter, such as a catecholamine, in the same neuron, which suggests the possibility that a neuron can release more than one transmitter substance. Of particular interest is the occurrence of VIP in presumed cholinergic neurons innervating exocrine glands in the cat, and the coexistence of a cholecystokinin (CCK)-like peptide in dopamine neurons projecting mainly to limbic areas. In the former system VIP seems to be responsible mainly for vasodilation, whereas acetylcholine mainly causes secretion. Furthermore, combined infusion of both substances in very low doses results in a marked potentiation of the secretory and vasodilatory responses. Thus, we have an example where two putative transmitters, released from the same nerve endings, seem to cooperate to activate a physiological response (secretion). With regard to the central CCK/dopamine neurons the type of interaction between the two coexisting transmitter candidates is at present unclear. It is suggested that elucidation of different types of coexistence phenomena may advance our understanding of chemical transmission at synapses under normal and pathological conditions, and may lead to new approaches to the treatment of some nervous disorders.

Adrenocorticotropic Hormone↗
PubMed1980

Peptidergic neurones.

More than 20 peptides have been identified in neurones of the brain, spinal cord and periphery. In several cases a peptide occurs together with a 'classical' transmitter in the same neurone. This raises new questions about the process of neurotransmission and may have important implications for our understanding and treatment of mental disorders.

Animals↗