Showing papers by "University of Texas Medical Branch published in 1982"
TL;DR: It is suggested that activation of cholinergic septal inputs to the hippocampus facilitates repetitive firing of pyramidal cells by turning off the M-conductance, without much change in the resting potential of the cell.
1,044 citations
TL;DR: Bullfrog lumbar sympathetic neurones were voltage‐clamped in vitro through twin micro‐electrodes to identify a new K+ current, the M‐current (IM), which was rapidly and totally inactivated at all potentials within its activation range.
Abstract: 1. Bullfrog lumbar sympathetic neurones were voltage-clamped in vitro through twin micro-electrodes. Four different outward (K(+)) currents could be identified: (i) a large sustained voltage-sensitive delayed rectifier current (I(K)) activated at membrane potentials more positive than -25 mV; (ii) a calcium-dependent sustained outward current (I(C)) activated at similar positive potentials and peaking at +20 to +60 mV; (iii) a transient current (I(A)) activated at membrane potentials more positive than -60 mV after a hyperpolarizing pre-pulse, but which was rapidly and totally inactivated at all potentials within its activation range; and (iv) a new K(+) current, the M-current (I(M)).2. I(M) was detected as a non-inactivating current with a threshold at -60 mV. The underlying conductance G(M) showed a sigmoidal activation curve between -60 and -10 mV, with half-activation at -35 mV and a maximal value (G(M)) of 84+/-14 (S.E.M.) nS per neurone. The voltage sensitivity of G(M) could be expressed in terms of a simple Boltzmann distribution for a single multivalent gating particle.3. I(M) activated and de-activated along an exponential time course with a time constant uniquely dependent upon voltage, maximizing at approximately 150 ms at -35 mV at 22 degrees C.4. Instantaneous current-voltage (I/V) curves were approximately linear in the presence of I(M), suggesting that the M-channels do not show appreciable rectification. However, the time- and voltage-dependent opening of the M-channels induced considerable rectification in the steady-state I/V curves recorded under both voltage-clamp and current-clamp modes between -60 and -25 mV. Both time- and voltage-dependent rectification in the voltage responses to current injection over this range could be predicted from the kinetic properties of I(M).5. It is suggested that I(M) exerts a strong potential-clamping effect on the behaviour of these neurones at membrane potentials subthreshold to excitation.
507 citations
TL;DR: It is deduced that in bullfrog sympathetic neurones IC is a fast current which can contribute a substantial fraction to the repolarizing current during an action potential, and is highly sensitive to external tetraethylammonium.
Abstract: Many neurones, when depolarized, exhibit two components of outward K+ current—the voltage-sensitive delayed rectifier current originally described in squid axons by Hodgkin and Huxley1, and an additional current triggered by the entry of Ca2+ ions2. These two currents have been termed IK and IC, respectively3. Previous experiments have indicated that both forms of K+ current are also present in vertebrate sympathetic neurones4–6. We have now studied the properties of IC in bullfrog sympathetic neurones, uncontaminated with IK, by injecting Ca2+ ions into the cells and measuring the resultant outward currents under voltage-clamp, in the manner previously used for large molluscan neurones7,8. We find three interesting properties of IC in these vertebrate neurones. First, it shows strong voltage sensitivity independent of the voltage sensitivity of the Ca2+ channels (which have been bypassed by the injection technique). Second, IC activates and deactivates very rapidly (τC≤20 ms at 0 mV), with stepped changes in membrane potential. Current fluctuation analysis and patch-clamp records of single-channel currents yielded evidence for appropriate short-lifetime ionic channels with a maximum conductance of ∼100 pS. Finally IC in ganglion cells is highly sensitive to external tetraethylammonium. We deduce that in these neurones IC is a fast current which can contribute a substantial fraction to the repolarizing current during an action potential.
408 citations
TL;DR: The effects of muscarinic agonists, luteinizing hormone‐releasing hormone (LHRH) analogues, uridine triphosphate (UTP) and divalent cations on K+‐currents in voltage‐clamped bullfrog sympathetic neurones have been studied.
Abstract: 1. The effects of muscarinic agonists, luteinizing hormone-releasing hormone (LHRH) analogues, uridine triphosphate (UTP) and divalent cations on K+-currents in voltage-clamped bullfrog sympathetic neurones have been studied.
2. Muscarine (1-10 μM), D-ala6 LHRH (1-5 μM), UTP (50-100 μM) and Ba2+ (1-4 mM) selectively depressed the M-current (IM), without appreciable effect on the delayed rectifier, Ca2+-activated or transient outward currents (IK, IC or IA).
3. IM-inhibition was characterized by: (a) elimination of slow current relaxations accompanying voltage jumps in the membrane potential range -30 to -60 mV; (b) reduced voltage-dependent chord conductance over this range with no change in the voltage-independent chord conductance at more negative membrane potentials; (c) suppression of outward rectification in the steady-state current—voltage curve between -70 and -25 mV; and (d) development of an inward current which increased in amplitude between -70 and -20 mV in proportion to the decrease in steady-state IM. The kinetics and voltage sensitivity of residual IM were unchanged.
4. The magnitude of the inward current produced by muscarine or LHRH could be accounted for quantitatively by the reduction in steady-state IM. No increase in leak current could be detected in the range -60 to -30 mV. In two cells muscarine (10 μM) increased the leak current and conductance at -70 to -100 mV, but not at more depolarized levels.
5. IM was not modified by removing extracellular Ca2+, adding a selective Ca2+-channel blocker (Cd2+), adding 1 mM-dibutyryl cyclic AMP or 8′Br cyclic GMP, or by intracellular ionophoresis of Ca2+, 8′Br cyclic GMP, dibutyryl cyclic AMP, GTP-γ-S or S-adenosylmethionine.
6. It is concluded that the principal effects of these agents in unclamped neurones — depolarization, increased input resistance, reduced outward rectification and increased excitability — are due entirely to a selective inhibition of IM. The intracellular transduction mechanism for IM inhibition is unknown.
392 citations
TL;DR: This review will emphasize recent developments in analyzing the composition of the haptoglobin molecules and the evolutionary implications of these findings.
Abstract: The question of how genetic material controls phenotypic expression was posed 60 years ago by Hermann Muller (1922), but the ability to answer the question awaited the development of biochemical techniques capable of dissecting and comparing purified proteins (Moore et al., 1958; Edman and Sjoquist, 1956; Ingram, 1957). Human haptoglobin has served as an unexpected source of information relating the mechanisms involved in genetic rearrangements to the linear sequence of amino acids within a protein. After developing a potent technique, starch gel electrophoresis, which proved capable of resolving and identifying previously unknown inherited variations in many human plasma proteins, Oliver Smithies and co-workers (Smithies, 1959; Smithies et al., 1962a, 1962b) demonstrated that serum haptoglobin molecules from different individuals varied one from another in a heritable way. Haptoglobin has served as an impressive paradigm of how genetic rearrangements can construct a polymorphic system and how, in the evolutionary process, old proteins can obtain new functions by utilizing amino acid sequences which have been ever so slightly altered. Excellent reviews have been written about haptoglobin, which can be consulted for further detail (Javid, 1978; Putnam, 1975; Pintera, 1971; Sutton, 1970; Giblett, 1969; Kirk, 1968; Schultze and Heremans, 1966). This review will emphasize recent developments in analyzing the composition of the haptoglobin molecules and the evolutionary implications of these findings.
332 citations
TL;DR: The immunologic system in human milk undergoes remarkable changes which may represent adaptations for the recipient infant, and secretory IgA antibody titers to E. coli increased in some individuals studied longitudinally suggesting that the enteromammary gland pathway of SIgA antibody production was active after several weeks of lactation.
291 citations
TL;DR: The findings strongly suggest the existence of a lymphoid-adrenal axis and the adrenocorticotropin-like material and interferon appear to be coordinately induced the differentially controlled products of different genes.
Abstract: Infection of hypophysectomized mice with Newcastle disease virus caused a time-dependent increase in corticosterone and interferon production. Prior treatment with dexamethasone completely inhibited the virus-induced elevation in corticosterone concentration, but did not significantly alter the interferon response. Lymphocytes appear to be the most likely source of an adrenocorticotropin-like substance that is responsible for the increased corticosterone, since spleen cells from the virus-infected, but not from control or dexamethasone-treated, hypophysectomized mice showed positive immunofluorescence with antibody to adrenocorticotropin-(1-13 amide). Thus the adrenocorticotropin-like material and interferon appear to be coordinately induced the differentially controlled products of different genes. These findings strongly suggest the existence of a lymphoid-adrenal axis.
262 citations
TL;DR: This paper contends that the notion of homeostasis is fundamentally inconsistent with systemic epistemology and should be replaced with the more compatible concept of coherence.
Abstract: The concept of homeostasis has served as a major building block, if not the cornerstone, of family theory and family therapy. Designed to account for the perceived stability of systems (and symptoms), homeostasis is an epistemologically flawed concept that has repetitively been used in the service of dualistic, animistic, and vitalistic interpretations of systems. Accordingly, homeostasis has led to quirky clinical formulations and a great deal of fuzzy theorizing. This paper contends that the notion of homeostasis is fundamentally inconsistent with systemic epistemology and should be replaced with the more compatible concept of coherence. Whereas homeostasis is a heuristic concept that is not part of a more encompassing theory, the concept of coherence is inseparable from the epistemology in which it is embedded.
230 citations
TL;DR: The results suggest that young children are no less and may be even more vulnerable to the deleterious effects of diffuse injury on memory and cognition.
Abstract: In comparison with age-matched groups who sustained mild to moderate head injury, children and adolescents with severe head injury initially exhibited memory deficit Cognitive impairment persisted primarily in the severely injured children, whereas the follow-up performance of severely injured adolescents more closely approximated that of age-matched patients with mild or moderate head injury The results suggest that young children are no less and may be even more vulnerable to the deleterious effects of diffuse injury on memory and cognition
201 citations
TL;DR: In contrast to the previously employed histofluorescence methods with which rapid photodecom-position of the yellow fluorescing cells and terminals was a constant problem, the peroxid enzyme-antiperoxidase (PAP) immunochemical method results in a relatively permanent marker for 5-HT neurons and terminals.
Abstract: Publisher Summary This chapter discusses the organization of descending serotonergic projections to the spinal cord The indolamine serotonin is believed to have important neurotransmitter and/or neuroregulatory roles in the descending pathways influencing various somatosensory, motor, and autonomic functions within the spinal cord The autonomic preganglionic neurons of the thoracic spinal cord, as well as the motoneurons of the ventral horn, are also under the influence of descending serotonergic cell groups Cells in these various motoneuron pools can be inhibited and/or excited by iontophoretic application of serotonin or by electrical stimulation of the descending serotonergic pathways In recent years, the introduction of immunocytochemistry to neurobiology has provided a very sensitive method for studying the organization of descending serotonergic pathways In contrast to the previously employed histofluorescence methods with which rapid photodecom-position of the yellow fluorescing cells and terminals was a constant problem, the peroxidase-antiperoxidase (PAP) immunochemical method results in a relatively permanent marker for 5-HT neurons and terminals
183 citations
TL;DR: The present study uses selective surgical ablations combined with electron microscopic analyses to determine the number of axons in yarious catagories in rat hypogastric, pelvic, and pudendal nerves, these being the nerves to the pelvic viscera in this animal.
Abstract: The present study uses selective surgical ablations combined with electron microscopic analyses to determine the number of axons in yarious catagories in rat hypogastric, pelvic, and pudendal nerves, these being the nerves to the pelvic viscera in this animal. Unmyelinated fibers predominate in all of these nerves. One of the most significant findings is that the pelvic nerve contains almost as many postganglionic sympathetic fibers as the hypogastric nerve. Previous investigators thought that the pelvic nerve supplied the parasympathetic inflow and the hypogastric nerve the sympathetic inflow to the pelvic viscera. The finding that there is a sizable sympathetic component in the pelvic nerve negates this idea, at least for the rat, and presumably calls for a reevaluation of the syndromes that arise from pelvic as opposed to hypogastric nerve section. Other findings of interest are (1) that there are unmyelinated efferent axons in the pudendal nerve, indicating that the pudendal is not a typical somatic nerve, (2) that the hypogastric nerve has a very small sensory component, and (3) that there are fibers surviving in the distal stumps of all these nerves, particularly the pelvic and hypogastric nerves.
TL;DR: This chapter discusses descending noradrenergic projections and their spinal terminations and employs the retrograde transport of HRP to identify spinally projecting cells, combined with conventional DBH immunocytochemistry to simultaneously visualize DBH in these same cells.
Abstract: Publisher Summary This chapter discusses descending noradrenergic projections and their spinal terminations. The noradrenergic innervation of the brain and spinal cord is derived from several distinct collections of catecholamine cells distributed from the rostral pons through the caudal medulla. With regard to the descending noradrenergic terminations in the spinal cord, lesions in known noradrenergic cell groups—such as the locus coeruleus—are followed by the subsequent loss of spinal cord noradrenergic fluorescent labeling. Other studies using the retrograde cell marker, horseradish peroxidase (HRP), show that spinal projections originate from cells in a number of brain stem regions known to contain noradrenergic cell bodies. In the experiments that are described in the chapter, two methods are used to identify noradrenergic (and possibly adrenergic) neurons that project to the spinal cord. One method involves the immunocytochemical localization of retrograde transported antibody to dopamine-b-hydroxylase (DBH) following injection into the spinal cord. The second method, a double labeling technique, employs the retrograde transport of HRP to identify spinally projecting cells, combined with conventional DBH immunocytochemistry to simultaneously visualize DBH in these same cells.
TL;DR: The transneuronal transport of wheat germ agglutinin demonstrates the existence of a mechanism whereby axonally transported glycomacromolecules might exert neurotrophic effects on postsynaptic cells.
TL;DR: Inward voltage-dependent calcium currents were recorded from clamped rat sympathetic ganglion cells using either one or two microelectrodes and ICa was reduced by adding norepinephrine, suggesting that nore Pinephrine acts by reducing the number of available calcium channels.
TL;DR: The hypothesis that there is an intrinsic structural difference between monoamine oxidase A and B is supported and it is demonstrated that immunoaffinity chromatography can physically resolve the two enzyme species in liver extracts.
Abstract: A monoclonal antibody was used to prepare immunoaffinity columns that efficiently bind monoamine oxidase B activity but not monoamine oxidase A activity from detergent extracts of human liver mitochondria. The only discrete polypeptide component that eluted from affinity columns with potassium thiocyanate migrated in sodium dodecyl sulfate-polyacrylamide gels with an apparent molecular weight of 59,000, as expected for human monoamine oxidase B. These results support the hypothesis that there is an intrinsic structural difference between monoamine oxidase A and B and demonstrate that immunoaffinity chromatography can physically resolve the two enzyme species in liver extracts.
TL;DR: The intensity of the subject's public speaking phobia predicted both degree of prestress anxiety relief from 10 mg diazepam and overall anxiety level, regardless of medication, throughout the experimental session.
Abstract: Normal male volunteers took single acute doses of either diazepam or placebo under double-blind conditions in three simulated public speaking experiments. Measures of palmar sweating and subjective anxiety showed that anticipation of speaking in public increased anxiety relative to baseline and prestress conditions, and performance of public speaking further increased anxiety. A dose-related anxiolytic effect of diazepam on subjective anxiety supported the model's clinical relevance. Moreover, the intensity of the subject's public speaking phobia predicted both degree of prestress anxiety relief from 10 mg diazepam and overall anxiety level, regardless of medication, throughout the experimental session. A measure of traditionalism predicted placebo and 5 mg diazepam response during prestress: As in previous clinical trials, high traditionalism scorers reported more relief from placebo, whereas low scorers showed more relief from diazepam.
TL;DR: The anatomical organization of the spinoreticular tract is consistent with a role for this pathway in nociception and is similar to the distribution of spinal cord neurons that project to the medial thalamus, but different from that of spinal neurons projecting to the ventrobasal complex.
Abstract: The distribution of the cells of origin of the primate spinoreticular tract was determined following injections of horseradish peroxidase (HPR) into the pontomedullary reticular formation in Macaca fascicularis Five animals received large bilateral injections which included the raphe nuclei and seven monkeys received smaller, unilateral injections Sections sampled were from upper cervical levels, the cervical enlargement, upper and lower thoracic levels, and lumbosacral levels The laminar distribution of spinoreticular cells in all spinal cord levels was comparable More than half of the labeled cells were located ventromedially, in laminae VII and VIII HRP-labeled cells were also found in the dorsal horn, primarily in the lateral reticulated part of lamina V Some cells were also found in laminae I and X Spinoreticular cells in the lumbosacral spinal cord mainly projected to the contralateral brainstem In the cervical enlargement, however, a bilateral distribution of cells was observed following unilateral injections of HRP Most spinoreticular cells were multipolar neurons with extensive dendritic ramifications The distribution of spinoreticular cells is similar to the distribution of spinal cord neurons that project to the medial thalamus, but different from that of spinal neurons projecting to the ventrobasal complex The anatomical organization of the spinoreticular tract is consistent with a role for this pathway in nociception
TL;DR: Immunocytochemical staining of the initial cell suspension by the avidin-biotin-peroxidase complex technique demonstrated that 8% of the cells contained LH-β and 12% contained FSH-β, and large, mature gonadotrophs were found in fraction 7, collected at 30.8/39.5 ml/min.
Abstract: Separation of gonadotrophs from cell suspensions of adult female rat pituitary glands by centrifugal elutriation was applied to the preparation of gonadotropin-enriched cells. Trypsin-dispersed cells (200–300 million) were loaded into the elutriator chamber while the rotor was operating at 1960 rpm, and cells were separated and collected in fractions by increasing the flow rate of medium through the rotor in increments from 11.8 to 39.5 ml/min. Loading and elutriation were completed in 80 min; cell recovery was 78/95%. Immunocytochemical staining of the initial cell suspension (ICS) by the avidin-biotin-peroxidase complex technique demonstrated that 8% of the cells contained LH-β and 12% contained FSH-β. After elutriation, large, mature gonadotrophs were found in fraction 7, collected at 30.8/39.5 ml/min. In this fraction, 40% of the cells stained for LH-β and 47% stained for FSH-(β. Since nearly half of the cells in fraction 7 were endothelial cells, the gonadotrophs constituted at least 80% of the secre...
TL;DR: The simian rotavirus SA11 was used to develop a simple, reliable, and efficient method to concentrate rotvirus from tap water, treated sewage, and raw sewage by absorption to and elution from Filterite fiberglass-epoxy filters.
Abstract: The simian rotavirus SA11 was used to develop a simple, reliable, and efficient method to concentrate rotavirus from tap water, treated sewage, and raw sewage by absorption to and elution from Filterite fiberglass-epoxy filters. SA11 adsorbed optimally to Filterite filters from water containing 0.5 mM AlCl3 at pH 3.5. Filter-bound virus was eluted with 0.05 M glycine-NaOH supplemented with 10% tryptose phosphate broth at pH 10. SA11 was quantitated by plaque assay, whereas human rotavirus was detected by immunofluorescence. The method was applied to detect rotavirus in raw and treated sewage at two Houston, Tex., sewage treatment plants. The sewage isolates were identified as rotavirus, probably a human strain, based on several criteria. The sewage isolates were detectable by an immunofluorescence test, using anti-SA11 serum which would detect the simian, human bovine, and porcine rotaviruses. No reaction was noted by immunofluorescence with the reoviruses or several common enteroviruses. The sewage isolates were neutralized by convalescent sera from a human adult and infant who had been infected by rotavirus as well as by a hyperimmune serum prepared in guinea pigs against purified human rotavirus. Preimmune or preillness sera did not react with the isolates by neutralization or immunofluorescence. The natural isolates were sensitive to pH 11 and other inactivating agents, similar to SA11. The buoyant density of the sewage isolates in CsCl gradients was 1.36 g/cm3, which is the value usually reported for complete, infectious rotavirus particles. The double-shelled particle diameter was 67.1 +/- 2.4 nm. Finally, electron micrographs of cell lysates inoculated with the sewage isolate showed particles displaying characteristic rotavirus morphology.
TL;DR: Serotonin-immunoreactive fibers have been observed in the dorsal columns of the golden hamster spinal cord and may play a role in analgesia produced by dorsal column stimulation.
TL;DR: Data suggest that a hereditary abnormality of vitamin D metabolism may be present in patients with hyperphosphatemic tumoral calcinosis, and failure of the normal feedback mechanism regulating the 25-hydroxy-1-alpha-hydroxylase enzyme is suggested as the major cause.
Abstract: Seven siblings with hyperphosphatemic tumoral calcinosis were studied using metabolic measures. Serum phosphorus and 1, 25-dihydroxycholecalciferol concentrations were significantly increased and serum parathyroid hormone and 25-hydroxycholecalciferol concentrations were significantly decreased in these subjects. Metabolic balance studies done in three of the siblings showed positive calcium and phosphorus balances, reflected by increased gastrointestinal absorption and decreased renal excretion. These data suggest that a hereditary abnormality of vitamin D metabolism may be present in patients with hyperphosphatemic tumoral calcinosis. Failure of the normal feedback mechanism regulating the 25-hydroxy-1-alpha-hydroxylase enzyme is suggested as the major cause. Although this defect could lead to many of the metabolic abnormalities seen in these patients, the overall contribution of altered vitamin D metabolism to the pathogenesis of tumoral calcinosis is not fully understood.
TL;DR: It is suggested that in some patients with AMM, more extensive cytogenetic alterations in the abnormal hematopoietic cells result in an inability to respond to androgen therapy and that the chromosome study is the test most accurate for predicting the outcome of therapy.
Abstract: The responses of 23 patients with agnogenic myeloid metaplasia (AMM) to androgen therapy were studied. Various clinical and laboratory parameters were analyzed for their value in determining response to therapy and length of survival. Fifty-seven percent of patients responded, as determined by a sustained increase in hematocrit within three months of therapy which thus eliminated the need for transfusions. Chromosome study of the abnormal hemic population was the best predictor of response: 92% of patients with normal chromosomes responded, while 78% of patients with chromosomal abnormalities did not. Responders had a mean survival time of five and a half years from the time of diagnosis as compared with two years for the nonresponders. The degree of thrombocytopenia, suppression of the ferrokinetic, and lack of activity in axial skeleton on bone marrow scans indicated severely compromised hemopoiesis in the nonresponders. The results suggest that in some patients with AMM, more extensive cytogenetic alterations in the abnormal hematopoietic cells result in an inability to respond to androgen therapy and that the chromosome study is the test most accurate for predicting the outcome of therapy. Cancer 49:308-313, 1982.
TL;DR: Three types of muscle fiber were recognized in the leg flexor of Carcinus maenas on the basis of histochemical staining for adenosine triphosphatase (ATPase) and oxidative en- zymes and analysis of fiber cross-sectional area and the oxidative capacity was correlated with the fiber type determined physiologically.
Abstract: Three types of muscle fiber were recognized in the leg flexor mus- cle of Carcinus maenas on the basis of histochemical staining €or the oxida- tive enzyme NADHD and analysis of fiber cross-sectional area. The distribution of these fiber types within the muscle is described. The oxidative capacity and cross-sectional area of the fiber was correlated with the fiber type determined physiologically. Key words crab leg muscle, NADHD histochemistry, fiber types, oxidative capacity Investigation of the contraction time of crus- tacean muscle fibers has revealed a number of muscle fiber types. Two extremes can be eas- ily recognized: "slow" and "fast." Intermedi- ate types can also be identified (Atwood, '76), although they are better considered as pre- senting a continuum from one extreme to the other. A variety of histological methods have also been used to identify muscle fiber types. These include histochemical staining for adenosine triphosphatase (ATPase) and oxidative en- zymes, and measurements of sarcomere length. Traditionally, sarcomere length has been used as an indicator of fiber type (Atwood, '72, '76). Recently sarcomere length and muscle fiber type have come to be regarded as syn- onomous, with short sarcomere fibers being equated to fast fibers and long sarcomere fi- bers being equated to slow fibers (Lang et al., '80; Ogonowski et al., '80). Such extrapolation may not be valid in all cases. More recently, Lang et al. ('80) have used ATPase activity as well as sarcomere length to classify fibers. Some confusion seems to have arisen with attempts to correlate these morphological and histochemical measures with physiological results. This is well shown by the perplexing conclusion that "the oxida- tive capacity of the muscle fibers is not di- rectly correlated with muscle fiber type (based on adenosine triphosphatase activity and sar- comere length)" (Lang et al., '80). Biologically, it would appear to be more meaningful to re- late metabolic status to intrinsic physiological function. Close examination of the photomicro- graphs of Lang et al.'s ('80) histochemical sec- tions (the reproduction being admittedly poor) suggests that they could readily support such a correlation between physiological fiber type, oxidative capacity, and ATPase activity. That
TL;DR: Damage to a region of skin can result in enhanced responsiveness of spinothalamic cells to stimuli applied in an undamaged region of the receptive field, provided the noxious heat was applied for a long enough time.
Abstract: Spinothalamic tract cells in anesthetized monkeys were found to respond to noxious cold stimuli (18/19 cells tested), as well as to noxious heat and noxious mechanical stimuli. Responses to repetition of the noxious cold stimuli after a series of noxious heat stimuli were enhanced. However, subtraction of the enhanced background activity that resulted from damage of the skin revealed that the enhanced response to noxious cold stimuli were due to superposition of the original responses upon an enhanced background activity, rather than to sensitization of the responses to noxious cold stimuli per se. Furthermore, the responses to innocuous mechanical stimuli applied either within the area that was damaged or outside this area were enhanced, provided the noxious heat was applied for a long enough time. Thus, damage to a region of skin can result in enhanced responsiveness of spinothalamic cells to stimuli applied in an undamaged region of the receptive field. The possible relationship between these observations and cutaneous hyperalgesia is discussed.
TL;DR: Catalase, superoxide dismutase, and dimethylsulfoxide were tested for their ability to prevent the cytotoxic effect of 6-hydroxydopamine (6-OHDA) on the human neuroblastoma line SY5Y.
TL;DR: The clinical relevance of CSF viral cultures was evaluated by reviewing the records of 390 patients whose CSF was cultured for virus during a two-year period and enterovirus was the only virus isolated from the CSF during the study period.
Abstract: The clinical relevance of CSF viral cultures was evaluated by reviewing the records of 390 patients whose CSF was cultured for virus during a two-year period The diagnoses at hospital discharge were aseptic meningitis, meningoencephalitis, or both in 111 patients, and enterovirus was isolated from the CSF or other test specimens in 46 patients (41%) The diagnosis or management of nearly one half of the patients from whom enterovirus was isolated was directly influenced by this information Hospitalization and the unnecessary use of antibiotics were shortened by at least 70 days Enterovirus was the only virus isolated from the CSF during the study period The CSF was more likely to be positive for an enterovirus if it was drawn from a young patient with aseptic meningitis during the summer or fall months The clinical data obtained from this study are discussed and compared with national statistics (JAMA1982;247:1843-1847)
TL;DR: Cells of origin of serotonergic and non-serotonergic projections to the caudal brain stem in the primate were examined using a double label technique and retrogradely labeled cells that did not stain for serotonin-like immunoreactivity were found primarily in the periaqueductal gray and the mesencephalic and pontine reticular formation.
TL;DR: These studies suggest that fiber systems containing serotonin innervated the adenohypophysis and can be detected with the most sensitive immunocytochemical methods.
Abstract: Immunocytochemical staining for serotonin, 5-hydroxytryptamine, in frozen sections of the pituitary resulted in the localization of fine, varicose fibers in specific regions of the adenohypophysis Stained fibers with beaded varicosities were observed entering the rostral zone of the adenohypophysis with blood vessels, coursing over the surface of the anterior lobe, and splitting into fine, varicose fibers in deeper portions of the lobe In both horizontal and sagittal sections, fibers were observed extending from the periphery of the gland to penetrate between the first 2-3 cell layers The intermediate lobe was even more extensively innertvated by fibers staining for serotonin These studies suggest that fiber systems containing serotonin innervated the adenohypophysis and can be detected with the most sensitive immunocytochemical methods
Journal Article•
TL;DR: It appears that PCP enhances DA release in a manner similar to the nonamphetamine class of central nervous system stimulants.
Abstract: Phencyclidine (PCP) elicits some behavioral and biochemical effects in rodents which resemble the effects of other central nervous system stimulants. Because an indirect dopaminergic agonist role has been proposed for PCP, we have compared the dopamine (DA)-releasing properties of PCP, amphetamine and certain nonamphetamine stimulants (methylphenidate, nomifensine, amfonelic acid). Striatal slices from male albino Sprague-Dawley rats were incubated with [3H]DA (10 nM) and then superfused in microperfusion chambers with a modified Tyrode's buffer (pH 7.4). Drug effects on [3H]DA release during depolarizing (40 mM KCl) and nondepolarizing (basal) conditions were determined by comparison with drug-free DA release rates in each preparation. PCP (3-100 microM) and all central nervous system stimulants tested produced a concentration-dependent increase of basal [3H]DA release (potency order: amfonelic acid, amphetamine greater than nomifensine, methylphenidate greater than PCP). At higher concentrations, PCP and the nonamphetamine stimulants also enhanced stimulated [3H]DA release. The effect of PCP on basal release was unchanged by the removal of extracellular calcium, addition of tetrodotoxin (1 microM) or pretreatment of rats with reserpine. Nomifensine (1 microM) enhanced the DA releasing actions of PCP and other nonamphetamine stimulants, but antagonized the DA releasing action of amphetamine. PCP, at concentrations which did not affect basal DA release (less than 1 microM), also antagonized the action of amphetamine. From these results, it appears that PCP enhances DA release in a manner similar to the nonamphetamine class of central nervous system stimulants.
TL;DR: The distribution of the descending serotonergic and peptidergic neurons in the raphe nuclei as well as quantitative data on their relative numbers suggest that a large fraction of raphe-spinal neurons contain serotonin co-existing with one or more peptides in the same cell.