Immunohistochemistry and spinal projections of the reticular formation in the northern leopard frog, Rana pipiens
american opossum; amphibian; brain-stem; central-nervous-system; descending; enkephalin; intermediolateral cell column; Neurosciences & Neurology; pathways; reticulospinal; serotonin; somatostatin; somatostatin-immunoreactive; stem reticulospinal nuclei; structures; substance P; substance-p-like; tyrosine-hydroxylase; ventral medulla-oblongata; Zoology
Over 30 nuclei have been identified in the reticular formation of rats, but only a small number of distinct reticular nuclei have been recognized in frogs. We used immunohistochemistry, retrograde tracing, and cell morphology to identify nuclei within the brainstem of Rana pipiens. FluoroGold was injected into the spinal cord, and, in the same frogs, antibodies to enkephalin, substance P, somatostatin, and serotonin were localized in adjacent sections. We identified many previously unrecognized reticular nuclei. The rhombencephalic reticular formation contained reticularis (r.) dorsalis; r. ventralis, pars alpha and pars beta; r. magnocellularis; r. parvocellularis; r. gigantocellularis; r. paragigantocellularis lateralis and dorsalis; r. pontis caudalis, pars alpha and pars beta; nucleus visceralis secundarius; r. pontis oralis, pars medialis and pars lateralis; raphe obscurus; raphe pallidus; raphe magnus; and raphe pontis. The mesencephalic reticular formation contained locus coeruleus-subcoeruleus, r. cuneiformis, r. subcuneiformis, raphe dorsalis-raphe centralis superior, and raphe linearis. Thus, the reticular formation of frog, which is an anamniote, is organized complexly and is similar to the reticular formation in amniotes. Because many of these nuclei may be homologous to reticular nuclei in mammals, we used mammalian terminology for frog reticular nuclei. (C) 1999 Wiley-Liss, Inc.
Adli D S H; Stuesse S L; Cruce W L R
Journal of Comparative Neurology
1999
1999-02
Journal Article or Conference Abstract Publication
n/a
Comparison of inotropic and chronotropic effects of vasoactive intestinal peptide in isolated dog atria
adenylate-cyclase; anesthetized dogs; atrium; autonomic nervous system; cardiac; conscious dogs; contractile force; heart rate; heart rate; isoproterenol; neuropeptide; neuropeptides; Neurosciences & Neurology; parasympathetic; performance; polypeptide; receptor; receptors; Substance P; vip
The positive chronotropic and inotropic effects of vasoactive intestinal peptide, VIP, were studied in an isolated canine right atrial preparation, Atria were removed, maintained in a bath, and perfused with Tyrode's solution. Contractile force and atrial depolarization were measured, VIP (18.8-600 pmol) was injected into a cannulated sinoatrial nodal artery and dose response curves were obtained. The mean EC(50) was similar for the inotropic and the chronotropic responses (136 and 144 pmol, respectively). Time courses of the onset and of recovery from the responses were measured. Times for onset of VIP effects were similar but, once the effect was initiated, rate of development of the response and recovery time from the responses were dose dependent, The increases in atrial rate lasted two to four times longer than did the increases in contractile force. Recovery from the chronotropic and inotropic responses to VIP differ, suggesting that the intracellular responses are coupled differently to the receptors. The responses to VIP were compared to those of 100 pmol isoproterenol, another positive chronotropic and inotropic agent. Isoproterenol was a slightly more potent chronotropic and inotropic agent than VIP. Desensitization of the responses was determined. Repeated exposures to VIP decreased the chronotropic response but not the inotropic response to VIP. There was no significant decrease in responsiveness to isoproterenol.
Wallick D W; Stuesse S L
Journal of the Autonomic Nervous System
1996
1996-12
Journal Article
<a href="http://doi.org/10.1016/s0165-1838(96)00091-4" target="_blank" rel="noreferrer noopener">10.1016/s0165-1838(96)00091-4</a>
Changes of the responses of single sympathetic ganglionic neurones to substance P following desensitization
adenylate-cyclase; binding; cells; desensitization; G protein; inhibition; k+ current; kinase-c; M current; muscarine; Neurosciences & Neurology; Pharmacology & Pharmacy; phosphorylation; protein alpha-subunits; receptor; rgs proteins; Substance P
1 The neuropeptide substance P (SP) exerts an excitatory effect on sympathetic neurones by inhibiting a time- and voltage-dependent potassium current. During prolonged application of SP, the response desensitizes. The changes in kinetics of the SP response in single neurones after desensitization have been studied in an attempt to gain some insight as to the molecular mechanism of desensitization in live, functioning neurones. 2 Desensitization to SP resulted in subsequent SP responses being smaller, but the time course was unchanged in desensitized cells compared with non-desensitized cells. 3 Experimental manipulations were performed to decrease receptor and G protein function for comparison to desensitization. Intracellular application of GDP betaS, to decrease G protein function, led to successive responses to agonist becoming smaller and slower. When functional muscarinic receptors were decreased by extracellular application of propylbenzilylcholine mustard (PrBCM), the response to muscarine became smaller, but the time course was unchanged compared with the change in time course produced by PrBCM vehicle alone. 4 The results have also been compared with simulations from a mathematical model of drug-receptor-G protein interactions. Under a constrained set of conditions, the model predicts that decreasing the size of the G protein pool will decrease both the magnitude and the time course of the response to agonist. Decreasing receptor levels results in a more efficient decrease in the magnitude of the response but no change in the time course of the response. 5 These data provide evidence that desensitization of the response to SP in single neurones results from a decrease in functional receptors.
Simmons M A
Journal of Autonomic Pharmacology
2001
2001-04
Journal Article
<a href="http://doi.org/10.1046/j.1365-2680.2001.00214.x" target="_blank" rel="noreferrer noopener">10.1046/j.1365-2680.2001.00214.x</a>
Characterization of a conformationally sensitive TOAC spin-labeled substance P
activation; adrenergic-receptor; agonist; amino-acid; binding-site; Biochemistry & Molecular Biology; Endocrinology & Metabolism; EPR; ESR; GPCR; neurokinin-1; nk-1; peptide-synthesis; Pharmacology & Pharmacy; protein-coupled-receptors; receptor; Substance P; tachykinin nk1 receptor; TOAC spin label
To probe the binding of a peptide agonist to a G-protein coupled receptor in native membranes, the spin-labeled amino acid analogue 4-amino-4-carboxy-2,2,6,6-tetramethyl-piperidino-1-oxyl (TOAC) was substituted at either position 4 or 9 within the substance P peptide (RPKPQQFFGLM-NH2), a potent agonist of the neurokinin-1 receptor. The affinity of the 4-TOAC analog is comparable to the native peptide while the affinity of the 9-TOAC derivative is similar to 250-fold lower. Both peptides activate receptor signaling, though the potency of the 9-TOAC peptide is substantially lower. The utility of these modified ligands for reporting conformational dynamics during the neurokinin-1 receptor activation was explored using EPR spectroscopy, which can determine the real-time dynamics of the TOAC nitroxides in solution. While the binding of both the 4-TOAC substance P and 9-TOAC substance P peptides to isolated cell membranes containing the neurokinin-1 receptor is detected, a bound signal for the 9-TOAC peptide is only obtained under conditions that maintain the receptor in its high-affinity binding state. In contrast, 4-TOAC substance P binding is observed by solution EPR under both low- and high-affinity receptor states, with evidence of a more strongly immobilized peptide in the presence of GDP. In addition, to better understand the conformational consequences of TOAC substitution into substance P as it relates to receptor binding and activation, atomistic models for both the 4- and 9-TOAC versions of the peptide were constructed, and the molecular dynamics calculated via simulated annealing to explore the influence of the TOAC substitutions on backbone structure. (C) 2008 Elsevier Inc. All rights reserved.
Shafer A M; Nakaie C R; Deupi X; Bennett V J; Voss J C
Peptides
2008
2008-11
Journal Article
<a href="http://doi.org/10.1016/j.peptides.2008.08.002" target="_blank" rel="noreferrer noopener">10.1016/j.peptides.2008.08.002</a>
TRENDS IN PLACE PREFERENCE CONDITIONING WITH A CROSS-INDEXED BIBLIOGRAPHY, 1957-1991
1-17 induces reward; Behavioral Sciences; beta-endorphin; brain-stimulation; conditioned place preference; drug affect; ethanol; mesolimbic dopamine system; motivational properties; Neurosciences & Neurology; nucleus-accumbens; place approach; positive reinforcing properties; rats; rewarding; self-administered; Substance P; ventral tegmental area
The purpose of this work is to present a perspective of the conditioned place preference (CPP) test by offering an overview of the empirical research from 1957-1991. The intent is not to extensively analyze the controversies inherent to any behavioral technique but rather to present a survey of research using a descriptive statistics approach to explore topical issues. The objectives of this work are three-fold: (a) to provide an exhaustive bibliography of the CPP literature including articles, journal abstracts, book chapters and critical reviews; (b) to provide a cross-index of identified key words/drugs tested; and (c) to give an overview of selected procedural issues underlying CPP testing.
Schechter M D; Calcagnetti D J
Neuroscience and Biobehavioral Reviews
1993
1993
Journal Article
<a href="http://doi.org/10.1016/s0149-7634(05)80228-3" target="_blank" rel="noreferrer noopener">10.1016/s0149-7634(05)80228-3</a>
Effect of aging on the substance P receptor, NK–1, in the spinal cord of rats with peripheral nerve injury.
ANIMAL models for aging; INJURIES to the peripheral nervous system; SPINAL cord injuries; SUBSTANCE P
Substance P (SP) levels in the spinal cords of very old rats are less than the levels in younger rats (Bergman et al., 1996). After injury to a peripheral nerve in young rats, immunoreactivity (ir) to the SP receptor, NK-1 (neurokinin-1), increases in the spinal cord ipsilateral to the injury and the increases are correlated with the development of thermal hyperalgesia (Goff et al., 1998). Thus we postulated that aged rats might display an increased sensitivity to thermal stimulation before peripheral nerve injury and that they might respond differently to injury than do younger rats. To test this hypothesis, we used the Bennett and Xie model (1988) of chronic constriction injury (CCI) to the sciatic nerve to induce a neuropathic pain condition. We investigated the effect of age on changes in NK-1 ir in superficial layers of the dorsal horn and on numbers of NK ir cells in deeper laminae at the L4-L5 levels of the spinal cord after CCI. NK-1 receptors were tagged immunohistochemically and their distribution quantified by use of computer-assisted image analysis. NK-1 ir changes were related to alterations in thermal and tactile sensitivity that developed after CCI in young, mature and aged (4-6, 14-16, and 24-26 months) Fischer F344 BNF1 hybrid rats. No differences in thermal or tactile sensitivity of young and aged rats were seen in the absence of nerve injury. After injury, aged rats developed thermal hyperalgesia and tactile allodynia more slowly than did the younger rats. NK-1 receptor ir and numbers of NK-1 ir cells in the dorsal horn increased with time post-injury in all three groups. NK-1 ir increases were correlated with the development of thermal hyperalgesia in those rats that displayed hyperalgesia. However, some rats developed an increased threshold to thermal stimuli (analgesia) and that also was correlated with increases in NK-1 ir. Thus NK-1 ir extent, while correlated with thermal sensitivity in the absence of injury, is not a specific marker for disturbances in one particular sensory modality; rather it increases with peripheral nerve injury per se. [ABSTRACT FROM AUTHOR]
Cruce William L R; Lovell John A; Crisp Terriann; Stuesse Sherry L
Somatosensory & Motor Research
2001
2001-01-16
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1080/08990220020021366" target="_blank" rel="noreferrer noopener">10.1080/08990220020021366</a>