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S J Watson

Publications and source records attributed to S J Watson.

At least 253 records · Page 14Linked to original sources
PubMed1985

Combined autoradiographic-immunocytochemical analysis of opioid receptors and opioid peptide neuronal systems in brain.

Using adjacent section autoradiography-immunocytochemistry, the distribution of [3H]naloxone binding sites was studied in relation to neuronal systems containing [Leu]enkephalin, dynorphin A, or beta-endorphin immunoreactivity in rat brain. Brain sections from formaldehyde-perfused rats show robust specific binding of [3H]naloxone, the pharmacological (mu-like) properties of which appear unaltered. In contrast, specific binding of the delta ligand [3H]D-Ala2,D-Leu5-enkephalin was virtually totally eliminated as a result of formaldehyde perfusion. Using adjacent section analysis, we have noted associations between [3H]naloxone binding sites and one, two, or all three opioid systems in different brain regions; however, in some areas, no apparent relationship could be observed. Within regions, the relationship was complex; for example, in caudate-putamen, patches of opioid receptors did not correspond to the distribution of enkephalin immunoreactivity, but there was a correspondence between subcallosal streaks of binding sites and enkephalin. The complexity of the association between [3H]naloxone binding sites and the multiple opioid systems, and previous reports of colocalization of mu and kappa receptors in rat brain, are inconsistent with a simple-one-to-one relationship between a given opioid precursor and opioid receptor subtype. Instead, since differential processing of the three precursors gives rise to peptides of varying receptor subtype potencies and selectivities, the multiple peptide-receptor relationships may point to a key role of post-translational processing in determining the physiological consequences of opioid neurotransmission.

Animals↗
PubMed1985

In situ hybridization histochemistry with synthetic oligonucleotides: strategies and methods.

In situ hybridization histochemistry is a useful method for localizing specific mRNA and studying the regulation of gene expression in an anatomical context. Previously, classical recombinant DNA and microbiological techniques have been required to identify and nick-translate the cloned DNAs necessary for in situ hybridization experiments. These requirements can be circumvented by the use of synthetic oligonucleotides complementary to the mRNA of interest. Compared to cloned cDNA probes, oligonucleotides are easy to manufacture, penetrate tissue much more easily, can be made to correspond to a sequence at any point in a known cDNA structure, and allow for the design of more precise controls for in situ studies. We describe a number of considerations in oligonucleotide probe design, including unique probe design from cDNA sequences and mixed probe design from protein primary structure data. The issues of species specificity, G-C content, probe length, tissue-specific mRNA expression, repeated sequences, non-coding region specific probes, and gene family homologies are discussed in an in situ hybridization context. Alternative strategies for mixed probe design are also considered. Information on the synthesis, purification, and sequence confirmation of oligonucleotides is then presented, followed by methods for labeling and using these probes for in situ hybridization histochemistry. The special considerations of specificity controls are addressed, including combined in situ hybridization histochemistry and immunocytochemistry, competition studies, the use of multiple hybridization probes, Tm studies, and Northern analysis of extracted RNA. The current and future directions of research with this technique are considered, with emphasis on the need to improve quantitation in order to facilitate the study of gene expression and regulation at the single cell level.

Animals↗
PubMed1985

Prodynorphin peptide immunocytochemistry in rhesus monkey brain.

The present study describes the immunocytochemical distribution of peptides derived from the prodynorphin precursor in the brain of the rhesus monkey (Macaca mulatta). Animals were treated with colchicine (intracerebroventricularly) prior to perfusion to enhance the observation of perikaryal immunoreactivity. Using antisera generated against dynorphin A(1-17), dynorphin B(1-13), and prodynorphin(186-208) (or bridge peptide), the anatomical distribution of dynorphin systems was mapped. The results indicate a widespread neuronal localization of immunoreactivity from the cerebral cortex to the caudal medulla. Anti-dynorphin B and anti-bridge peptide sera proved useful for the demonstration of neuronal perikarya, while the dynorphin A antiserum was best for localizing terminal projection fields. Immunoreactive perikarya are located in numerous brain loci, including the cingulate cortex, caudate nucleus, amygdala, hypothalamus (especially the magnocellular nuclei), thalamus, substantia grisea centralis, parabrachial nucleus, nucleus tractus solitarius, and other nuclei. In addition, fiber and terminal immunoreactivity are seen in varying densities in the striatum and pallidum, substantia innominata, hypothalamus, substantia nigra pars reticulata, parabrachial nucleus, spinal trigeminal nucleus, and other areas. The distribution of prodynorphin peptides in the brain of the monkey is similar to that described for the rat brain; however, significant differences also exist. Other interspecies differences in the anatomy of prodynorphin and proenkephalin neuronal systems in the monkey and human brain are further discussed.

Animals↗
PubMed1985

The comparative distribution of enkephalin, dynorphin and substance P in the human globus pallidus and basal forebrain.

Three neuropeptides, enkephalin, dynorphin, and substance P appear in the globus pallidus in a unique pattern termed woolly fibers as described previously [Haber and Nauta (1983) Neuroscience 9, 245-260]. The comparative distribution of these fibers are described in the human globus pallidus and basal forebrain area. The results show two main points: The human globus pallidus is a larger, more intricately shaped structure than previously thought, invading several limbic-related basal forebrain regions. There are differences in the distribution patterns of the neuropeptides described, so that they are found in overlapping, but not matching regions. The relationship between the peptide distribution and what is known about the functional (limbic vs motor) circuitry of the region is discussed.

Diencephalon↗
PubMed1984

Localization of neurons containing pro-opiomelanocortin-related peptides in the hypothalamus and midbrain of the lizard, Anolis carolinensis: evidence for region-specific processing of beta-endorphin.

Immunohistochemical analyses of the lizard-brain, following colchicine pretreatment, revealed two populations of POMC-producing cell bodies located in medial-basal hypothalamus and the mesencephalic tegmentum. Analyses of extracts of lizard brain regions by radioimmunoassay and gel filtration chromatography indicate that beta-endorphin-sized and alpha-MSH-sized peptides are the major POMC-related end products. Evidence is presented for region-specific processing of beta-endorphin in the lizard brain.

Animals↗
PubMed1984

Beta-endorphin/ACTH immunocytochemistry in the CNS of the lizard Anolis carolinensis: evidence for a major mesencephalic cell group.

The immunocytochemical distribution of beta-endorphin and other proopiomelanocortin (POMC) peptides in the central nervous system of the lizard Anolis carolinensis was determined. Colchicine pretreatment was used to enhance perikaryal immunoreactivity. A major finding of this study is the localization of a previously undetected mesencephalic cell group which exhibits immunoreactivity to beta-endorphin, ACTH, and alpha-MSH. The perikarya of these neurons are large, bipolar, and situated in the mesencephalic tegmental area. They appear to project to the mesencephalic central gray and other brainstem structures. In contrast, the immunoreactive parvicellular perikarya of the medial-basal hypothalamus, corresponding to the POMC perikarya of the rodent arcuate nucleus, exhibit major rostral projections to various telencephalic and diencephalic structures. The exact extent of fiber projections and innervation patterns arising from either of these two groups is not clear at this time and will require further analyses. Scattered fiber immunoreactivity was also seen in the medial cerebral cortex and the striatal complex, regions which apparently are not innervated by beta-endorphin fibers in the rodent brain. Also, no immunoreactivity was seen to an antiserum to the 16K peptide of POMC. Other similarities and differences in the brain distribution of POMC in reptiles and mammals are discussed.

Adrenocorticotropic Hormone↗
PubMed1984

Abnormal essential fatty acid levels in plasma of women with premenstrual syndrome.

Premenstrual syndrome is now recognized as a condition that probably has an endocrine or biochemical basis. However, it has proved difficult to demonstrate any consistent significant differences from normal in any parameter measured to date. We have measured essential fatty acid levels in phospholipids in plasma taken from 42 women with well-defined premenstrual syndrome. The women were not on any treatment during the cycles when samples were taken in both follicular and luteal phases. The levels of linoleic acid, the main dietary n-6 essential fatty acid, were significantly above normal, indicating no deficit of intake or absorption. In spite of this, concentrations of all metabolites of linoleic acid were significantly reduced, suggesting a defect in conversion of linoleic acid to gamma-linolenic acid. Possibly in compensation, levels of n-3 essential fatty acids were elevated. The same abnormalities were present in both follicular and luteal phases. This abnormality cannot therefore be the direct cause of the symptoms that appear in the luteal phase, but it may sensitize tissues so that they respond abnormally to normal levels of reproductive hormones.

Adult↗
PubMed1984

Strategies for studying opioid peptide regulation at the gene, message and protein levels.

Three opioid peptide precursors have been isolated and characterized in endocrine and nervous tissue: pro-opiomelanocortin, pro-enkephalin, and pro-dynorphin. Since each of those opioid peptide systems have been extensively characterized both biochemically and anatomically, this review will focus on strategies for studying the regulation of these systems at the levels of gene transcription, message translation, post-translational processing, secretion, and target cell receptor interaction.

Animals↗
PubMed1984

Proopiomelanocortin peptide immunocytochemistry in rhesus monkey brain.

The immunocytochemical distribution of proopiomelanocortin (POMC) peptides (beta-endorphin, ACTH, alpha-MSH, 16K fragment) was studied in the brain of the rhesus monkey (Macaca mulatta). Some animals were administered colchicine intracerebroventricularly prior to sacrifice to enhance the visualization of perikaryal immunoreactivity. Immunoreactive perikarya are localized to hypothalamic infundibular nucleus, giving rise to several distinct projections. Rostral projections extend through midline diencephalic and preoptic areas, and enter the telencephalon. Along this course, immunoreactive fibers are seen in midline hypothalamic and preoptic nuclei, nucleus of the diagonal band, olfactory tubercle, nucleus accumbens, bed nucleus of stria terminalis, septum, and other limbic structures in telencephalon. Caudal to the anterior commissure, some fibers ascend dorsally to enter the midline thalamus, which they innervate. Lateral projections of the infundibular perikarya course through the medial-basal hypothalamus, dorsal to the optic tracts, and enter the amygdala region where they innervate more medially situated amygdaloid nuclei. Caudal projections of the POMC neurons also extend through midline diencephalon, some coursing along a periventricular path to innervate midline hypothalamic and thalamic nuclei. This projection extends into the mesencephalic substantia grisea centralis and may also contribute to the innervation of more dorsally situated nuclei in the pons and medulla, such as the parabrachial nuclei and nucleus tractus solitarius. Other caudal projections originating in the hypothalamus course through the ventral tegmentum of mesencephalon and pons and may contribute to the innervation of midline raphe and other ventrally situated nuclei in the pons and medulla. The distribution of immunoreactive perikarya and fibers in the brain of rhesus monkey is strikingly similar to that found in the rat brain. However, subtle differences appear to exist in the innervation patterns of particular brain regions.

Adrenocorticotropic Hormone↗
PubMed1984

Anatomical relationship between opioid peptides and receptors in rhesus monkey brain.

To determine whether opioid peptide-receptor pharmacological association found in vitro (e.g., enkephalin-delta, dynorphin-kappa) predict anatomical relationships in situ, immunocytochemical and receptor autoradiographic studies were carried out on adjacent sections from the same brains of formaldehyde-perfused rhesus monkeys. Apparent mu and kappa opioid receptors (labeled, respectively, by [3H] naloxone and [3H]bremazocine under different incubation conditions), but not delta opioid receptors (labeled by [3H]D-Ala2, D-Leu5-enkephalin), survived the fixation procedure, and were found to be colocalized throughout the brain. We have observed complex associations between these binding sites and one, two, or all three opioid peptide systems (i.e., proopiomelanocortin, proenkephalin, and prodynorphin) in different brain regions. These multiple opioid peptide-receptor subtype associations are apparent, for example, in neural systems involved in the processing of pain stimuli, and may be important for mediating different types of analgesia. Since differential processing of proenkephalin and prodynorphin can give rise to opioids of varying receptor selectivities, the colocalization of opioid receptor subtypes may signify that such processing is a key regulatory event in determining which receptor subtype is activated and, thus, the physiological consequences of opioid neurotransmission.

Animals↗
PubMed1983

Colocalization of proenkephalin peptides in rat brain neurons.

A serial, thin-section immunocytochemical study of the anatomical distribution of Leu-enkephalin and BAM-22P (an adrenal proenkephalin peptide) demonstrated that both immunoreactivities occur within the same neurons throughout brain. However, neither peptide immunoreactivity could be observed in neurons containing dynorphin A immunoreactivity. These results are consistent with the possibility that the enkephalin precursor in brain is similar to that sequenced in adrenal, but fail to support the hypothesis that the dynorphin precursor is a major source of Leu-enkephalin in brain.

Animals↗
PubMed1983

Enkephalin systems in diencephalon and brainstem of the rat.

The immunocytochemical distribution of [Leu]enkephalin and an adrenal enkephalin precursor fragment (BAM-22P) immunoreactivity was investigated in the diencephalon and brainstem of rats pretreated with relatively high doses of colchicine (300-400 micrograms/10 microliters intracerebroventricularly). The higher ranges of colchicine pretreatment allowed the visualization of extensive enkephalin-containing systems in these brain regions, some of which are reported for the first time. Immunoreactive perikarya were found in many hypothalamic and thalamic nuclei, interpeduncular nucleus, substantia nigra, the colliculi, periaqueductal gray, parabrachial nuclei, trigeminal motor and spinal nuclei, nucleus raphe magnus and other raphe nuclei, nucleus reticularis paragigantocellularis, vestibular nuclei, several noradrenergic cell groups, nucleus tractus solitarius, as well as in the spinal cord dorsal horn. In addition to the above regions, immunoreactive fibers were also noted in the habenular nuclei, trigeminal sensory nuclei, locus coeruleus, motor facial nucleus, cochlear nuclei, dorsal motor nucleus of the vagus, and hypoglossal nucleus. When adjacent sections of those stained for [Leu]enkephalin were processed for BAM-22P immunoreactivity, it was found that these two immunoreactivities were distributed identically at almost all anatomical locations. BAM-22P immunoreactivity was generally less pronounced and ws preferentially localized to neuronal perikarya. The results of the present as well as the preceding studies (Khachaturian et al., '83) strongly suggest substantial structural similarity between the adrenal proenkephalin precursor and that which occurs in the brain. Also discussed are some differences and parallels between the distribution of [Leu]enkephalin and dynorphin immunoreactivities.

Animals↗
PubMed1983

Some of the alpha-NH2-acetylated beta-endorphin-like material in rat and monkey pituitary and brain is acetylated alpha- and beta-endorphin.

There are several studies demonstrating the existence of alpha-NH2-acetylated (N-Ac) forms of beta-endorphin in the intermediate lobe of several species (1,4,6). These include N-Ac-beta-endorphin (1-31), N-Ac-beta-endorphin (1-27) and N-Ac-beta-endorphin (1-26). The existence of N-acetylation of brain beta-endorphin is more controversial (5,6). Using molecular sieving, HPLC, and several radioimmunoassays, either directed at the midportion of beta-endorphin or at only N-acetylated opioids, we have studied brain multiple forms (cf. Akil, 1982). We have noted that little or no acetylation of beta-endorphin-sized material occurs in hypothalamus, and a small amount of N-acetylation appears to take place in the midbrain and the medulla. These results will be described in detail elsewhere (Akil et al., in preparation), but point the fact that processing of beta-endorphin (1-31) in brain is different than either lobe, with the production of beta-endorphin (1-27) and beta-endorphin (1-26) being more predominant in brain terminal areas than in the neuro-intermediate lobe. In the course of these experiments we noted the existence of a smaller-sized material which reacted with our N-acetyl-beta-endorphin antibody. The following study describes the partial characterization of this material as N-Ac-alpha- and N-Ac-beta-endorphin (i.e., the N-acetylated forms of beta-endorphin (1-17) and beta-endorphin (1-16).

Animals↗
PubMed1983

The comparison between enkephalin-like and dynorphin-like immunoreactivity in both monkey and human globus pallidus and substantia nigra.

The distribution of [Met]-Enkephalin and Dynorphin-like immunoreactivity were studied in the monkey and human globus pallidus and substantia nigra. These distributions were compared to those seen in these structures of the rat. Interspecies variations were observed in the substantia nigra, and in both pallidal segments. Differences between the distribution of the two opiate peptides occurred mostly in the limbic-related globus pallidus.

Animals↗
PubMed1983

POMC in rhesus anterior pituitary and plasma: evidence of N-acetylated beta-endorphin and alpha-MSH.

Pro-opiomelanocortin (POMC) related peptides have been studied in rat tissue and plasma, but they have not been well characterized in the rhesus monkey. Since monkey pituitary may be more similar to the human pituitary than the rat, we have characterized POMC related peptides by immunocytochemical, multiple radioimmunoassays (RIA's) and molecular sieving chromatography. Immunocytochemical staining demonstrated N-acetylated- beta-endorphin (N-Ac- beta-End) and alpha-MSH in a few corticotrophs. RIA's of crude anterior pituitary extract and molecular sieving chromatography demonstrates that the major portion is beta-End sized with a significant proportion being N-acetylated and an alpha-MSH peak. Molecular sieving chromatography of extracted plasma demonstrated a similar pattern to that seen in the anterior pituitary. These data suggest that rhesus monkey processes POMC differently than rat or man.

Animals↗
PubMed1983

Ontogeny of opioid and related peptides in the rat cns and pituitary: an immunocytochemical study.

The development of proopiomelanocortin (POMC) derived peptides was compared to that of leucine-enkephalin ([Leu]ENK) and dynorphin A (DYN-A) immunoreactivity (i.r.) in the rat CNS and pituitary gland. POMC i.r. appeared first in hypothalamic neurons on embryonic day E12, in pituitary anterior lobe (AL) cells on E15, in pituitary intermediate lobe (IL) cells on E16, and in perikarya of the nucleus tractus solitarius on E17. In the fetal stages (E19-22), all POMC systems appeared adult-like; however, peak i.r. occurred between postnatal days P21-28. The development of alpha-MSH (a-MSH) i.r. was dissimilar to that of other POMC peptides including beta-endorphin (B-End). In contrast, both [Leu]ENK and DYN-A i.r. appeared in later embryonic stages (E16-17), and their maturation lagged behind that of POMC peptides. Peak i.r. for these latter peptides also occurred between P21-28.

Aging↗