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S Colaprete - One of the best experts on this subject based on the ideXlab platform.
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Peptidergic transmission in the brain iv sex hormone dependence in the vasopressin oxytocin system
Peptides, 1991Co-Authors: David Albeck, T Smock, K Raese, K Paynter, S. Von Arnold, S ColapreteAbstract:Abstract The medial amygdaloid nucleus (AME) synthesizes a peptide similar to arginine vasopressin and projects Peptidergic fibers to the ipsilateral hippocampus in the male rat. In previous studies, we have shown that the peptide acts as a transmitter and, using in vitro and in vivo electrophysiology, we have characterized its mechanism of action. Previous anatomical work has shown that the Peptidergic fibers are more dense in male rats than females and are obliterated entirely by castration. Here we report the results of our attempt to find an electrophysiological correlate of these anatomical findings. First, we show specific mediation by a vasopressin- or oxytocin-like peptide by use of a structural vasotocin antagonist. Then we show that castration obliterates the Peptidergic signal in males. However, we were unable to find any sex difference that corresponded to the male/female disparity noted in the density of the Peptidergic fibers. The strength, nature and stimulus-response characteristics were the same between males and females. Apart from a very subtle difference in the duration of the signal, no physiological correlate of the sexual dimorphism could be found with our techniques. We conclude that the neurophysiology partly complements the anatomy and biochemistry of this system.
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Peptidergic transmission in the brain. IV. Sex hormone dependence in the vasopressin/oxytocin system
Peptides, 1991Co-Authors: David Albeck, T Smock, K Raese, K Paynter, S. Von Arnold, S ColapreteAbstract:The medial amygdaloid nucleus (AME) synthesizes a peptide similar to arginine vasopressin and projects Peptidergic fibers to the ipsilateral hippocampus in the male rat. In previous studies, we have shown that the peptide acts as a transmitter and, using in vitro and in vivo electrophysiology, we have characterized its mechanism of action. Previous anatomical work has shown that the Peptidergic fibers are more dense in male rats than females and are obliterated entirely by castration. Here we report the results of our attempt to find an electrophysiological correlate of these anatomical findings. First, we show specific mediation by a vasopressin- or oxytocin-like peptide by use of a structural vasotocin antagonist. Then we show that castration obliterates the Peptidergic signal in males. However, we were unable to find any sex difference that corresponded to the male/female disparity noted in the density of the Peptidergic fibers. The strength, nature and stimulus-response characteristics were the same between males and females. Apart from a very subtle difference in the duration of the signal, no physiological correlate of the sexual dimorphism could be found with our techniques. We conclude that the neurophysiology partly complements the anatomy and biochemistry of this system.
T Smock - One of the best experts on this subject based on the ideXlab platform.
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Orthodromic Activation of Peptidergic Cells in the Medial Amygdala
Peptides, 1997Co-Authors: Stephen Murphy, Ian Beall, April Renner, T SmockAbstract:Abstract Murphy, S., I. Beall, A. Renner and T. Smock. Orthodromic activation of Peptidergic cells in the medial amygdala. Peptides 18(8) 1175–1177, 1997.—Electrical recordings from vasopressin-containing cells in the medial amygdala were obtained. Electrical stimulation of one major afferent structure, the accessory olfactory bulb, invariably elicited single unit discharge in the Peptidergic cells and set up a field potential indicating widespread excitation in the structure. Pheromonal stimuli, normally borne into the brain by the accessory olfactory bulb, were ineffective in activating the medial amygdala. These results in combination with preexisting research suggest that the accessory olfactory bulb is an important influence, but not the only influence, on the activity of the Peptidergic cells.
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A Peptidergic circuit for reproductive behavior.
Brain Research, 1992Co-Authors: T Smock, S. Von Arnold, David Albeck, P. Emerson, J. Garritano, K. Burrows, W. Derber, C. Sanson, Kurt Marrs, H. WeatherlyAbstract:A projection from the medial amygdaloid nucleus to the hippocampus and septum probably uses vasopressin as a transmitter. The nucleus synthesizes vasopressin and activation of the nucleus has a hippocampal effect that is completely blocked by a vasopressin antagonist. The afferent and efferent projections of this Peptidergic nucleus suggest a possible role for the system in sexual behavior. Stimulation of the nucleus inhibits the output of the hippocampus in both genders and reorganizes behavior for a period of 15-20 min. In males, the effect of Peptidergic activation is to produce a behavior that resembles the post-ejaculatory interval in coitus. This state is characterized by an EEG that resembles slow-wave sleep and by ultrasonic vocalizations at a characteristic frequency of 22 kHz. Castration in either gender causes depletion of the peptide from the target fields and eliminates the Peptidergic signal in the hippocampus after about 15 weeks. The effects of castration in males can be reversed by testosterone replacement. The fluctuation of estrogen levels in rat plasma during the estrus cycle happens too quickly to impact the Peptidergic system, and thus there is no significant change in the strength of the Peptidergic signal among the proestrus, estrus, metestrus and diestrus stages. This fact permits study of the physiology of the system without concern for stage of estrus but does not permit conclusions regarding its function in females.
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Peptidergic transmission in the brain iv sex hormone dependence in the vasopressin oxytocin system
Peptides, 1991Co-Authors: David Albeck, T Smock, K Raese, K Paynter, S. Von Arnold, S ColapreteAbstract:Abstract The medial amygdaloid nucleus (AME) synthesizes a peptide similar to arginine vasopressin and projects Peptidergic fibers to the ipsilateral hippocampus in the male rat. In previous studies, we have shown that the peptide acts as a transmitter and, using in vitro and in vivo electrophysiology, we have characterized its mechanism of action. Previous anatomical work has shown that the Peptidergic fibers are more dense in male rats than females and are obliterated entirely by castration. Here we report the results of our attempt to find an electrophysiological correlate of these anatomical findings. First, we show specific mediation by a vasopressin- or oxytocin-like peptide by use of a structural vasotocin antagonist. Then we show that castration obliterates the Peptidergic signal in males. However, we were unable to find any sex difference that corresponded to the male/female disparity noted in the density of the Peptidergic fibers. The strength, nature and stimulus-response characteristics were the same between males and females. Apart from a very subtle difference in the duration of the signal, no physiological correlate of the sexual dimorphism could be found with our techniques. We conclude that the neurophysiology partly complements the anatomy and biochemistry of this system.
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Peptidergic transmission in the brain. IV. Sex hormone dependence in the vasopressin/oxytocin system
Peptides, 1991Co-Authors: David Albeck, T Smock, K Raese, K Paynter, S. Von Arnold, S ColapreteAbstract:The medial amygdaloid nucleus (AME) synthesizes a peptide similar to arginine vasopressin and projects Peptidergic fibers to the ipsilateral hippocampus in the male rat. In previous studies, we have shown that the peptide acts as a transmitter and, using in vitro and in vivo electrophysiology, we have characterized its mechanism of action. Previous anatomical work has shown that the Peptidergic fibers are more dense in male rats than females and are obliterated entirely by castration. Here we report the results of our attempt to find an electrophysiological correlate of these anatomical findings. First, we show specific mediation by a vasopressin- or oxytocin-like peptide by use of a structural vasotocin antagonist. Then we show that castration obliterates the Peptidergic signal in males. However, we were unable to find any sex difference that corresponded to the male/female disparity noted in the density of the Peptidergic fibers. The strength, nature and stimulus-response characteristics were the same between males and females. Apart from a very subtle difference in the duration of the signal, no physiological correlate of the sexual dimorphism could be found with our techniques. We conclude that the neurophysiology partly complements the anatomy and biochemistry of this system.
David Albeck - One of the best experts on this subject based on the ideXlab platform.
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A Peptidergic circuit for reproductive behavior.
Brain Research, 1992Co-Authors: T Smock, S. Von Arnold, David Albeck, P. Emerson, J. Garritano, K. Burrows, W. Derber, C. Sanson, Kurt Marrs, H. WeatherlyAbstract:A projection from the medial amygdaloid nucleus to the hippocampus and septum probably uses vasopressin as a transmitter. The nucleus synthesizes vasopressin and activation of the nucleus has a hippocampal effect that is completely blocked by a vasopressin antagonist. The afferent and efferent projections of this Peptidergic nucleus suggest a possible role for the system in sexual behavior. Stimulation of the nucleus inhibits the output of the hippocampus in both genders and reorganizes behavior for a period of 15-20 min. In males, the effect of Peptidergic activation is to produce a behavior that resembles the post-ejaculatory interval in coitus. This state is characterized by an EEG that resembles slow-wave sleep and by ultrasonic vocalizations at a characteristic frequency of 22 kHz. Castration in either gender causes depletion of the peptide from the target fields and eliminates the Peptidergic signal in the hippocampus after about 15 weeks. The effects of castration in males can be reversed by testosterone replacement. The fluctuation of estrogen levels in rat plasma during the estrus cycle happens too quickly to impact the Peptidergic system, and thus there is no significant change in the strength of the Peptidergic signal among the proestrus, estrus, metestrus and diestrus stages. This fact permits study of the physiology of the system without concern for stage of estrus but does not permit conclusions regarding its function in females.
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Peptidergic transmission in the brain iv sex hormone dependence in the vasopressin oxytocin system
Peptides, 1991Co-Authors: David Albeck, T Smock, K Raese, K Paynter, S. Von Arnold, S ColapreteAbstract:Abstract The medial amygdaloid nucleus (AME) synthesizes a peptide similar to arginine vasopressin and projects Peptidergic fibers to the ipsilateral hippocampus in the male rat. In previous studies, we have shown that the peptide acts as a transmitter and, using in vitro and in vivo electrophysiology, we have characterized its mechanism of action. Previous anatomical work has shown that the Peptidergic fibers are more dense in male rats than females and are obliterated entirely by castration. Here we report the results of our attempt to find an electrophysiological correlate of these anatomical findings. First, we show specific mediation by a vasopressin- or oxytocin-like peptide by use of a structural vasotocin antagonist. Then we show that castration obliterates the Peptidergic signal in males. However, we were unable to find any sex difference that corresponded to the male/female disparity noted in the density of the Peptidergic fibers. The strength, nature and stimulus-response characteristics were the same between males and females. Apart from a very subtle difference in the duration of the signal, no physiological correlate of the sexual dimorphism could be found with our techniques. We conclude that the neurophysiology partly complements the anatomy and biochemistry of this system.
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Peptidergic transmission in the brain. IV. Sex hormone dependence in the vasopressin/oxytocin system
Peptides, 1991Co-Authors: David Albeck, T Smock, K Raese, K Paynter, S. Von Arnold, S ColapreteAbstract:The medial amygdaloid nucleus (AME) synthesizes a peptide similar to arginine vasopressin and projects Peptidergic fibers to the ipsilateral hippocampus in the male rat. In previous studies, we have shown that the peptide acts as a transmitter and, using in vitro and in vivo electrophysiology, we have characterized its mechanism of action. Previous anatomical work has shown that the Peptidergic fibers are more dense in male rats than females and are obliterated entirely by castration. Here we report the results of our attempt to find an electrophysiological correlate of these anatomical findings. First, we show specific mediation by a vasopressin- or oxytocin-like peptide by use of a structural vasotocin antagonist. Then we show that castration obliterates the Peptidergic signal in males. However, we were unable to find any sex difference that corresponded to the male/female disparity noted in the density of the Peptidergic fibers. The strength, nature and stimulus-response characteristics were the same between males and females. Apart from a very subtle difference in the duration of the signal, no physiological correlate of the sexual dimorphism could be found with our techniques. We conclude that the neurophysiology partly complements the anatomy and biochemistry of this system.
Amy B Macdermott - One of the best experts on this subject based on the ideXlab platform.
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Characterization of sensory neuron subpopulations selectively expressing green fluorescent protein in phosphodiesterase 1C BAC transgenic mice
Molecular Pain, 2006Co-Authors: Carole Torsney, Rebecca L Anderson, Kerry-anne G Ryce-paul, Amy B MacdermottAbstract:Background The complex neuronal circuitry of the dorsal horn of the spinal cord is as yet poorly understood. However, defining the circuits underlying the transmission of information from primary afferents to higher levels is critical to our understanding of sensory processing. In this study, we have examined phosphodiesterase 1C ( Pde1c ) BAC transgenic mice in which a green fluorescent protein (GFP) reporter gene reflects Pde1c expression in sensory neuron subpopulations in the dorsal root ganglia and spinal cord. Results Using double labeling immunofluorescence, we demonstrate GFP expression in specific subpopulations of primary sensory neurons and a distinct neuronal expression pattern within the spinal cord dorsal horn. In the dorsal root ganglia, their distribution is restricted to those subpopulations of primary sensory neurons that give rise to unmyelinated C fibers (neurofilament 200 negative). A small proportion of both non-Peptidergic (IB4-binding) and Peptidergic (CGRP immunoreactive) subclasses expressed GFP. However, GFP expression was more common in the non-Peptidergic than the Peptidergic subclass. GFP was also expressed in a subpopulation of the primary sensory neurons immunoreactive for the vanilloid receptor TRPV1 and the ATP-gated ion channel P2X_3. In the spinal cord dorsal horn, GFP positive neurons were largely restricted to lamina I and to a lesser extent lamina II, but surprisingly did not coexpress markers for key neuronal populations present in the superficial dorsal horn. Conclusion The expression of GFP in subclasses of nociceptors and also in dorsal horn regions densely innervated by nociceptors suggests that Pde1c marks a unique subpopulation of nociceptive sensory neurons.
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Characterization of sensory neuron subpopulations selectively expressing green fluorescent protein in phosphodiesterase 1C BAC transgenic mice
Molecular Pain, 2006Co-Authors: Carole Torsney, Rebecca L Anderson, Kerry-anne G Ryce-paul, Amy B MacdermottAbstract:The complex neuronal circuitry of the dorsal horn of the spinal cord is as yet poorly understood. However, defining the circuits underlying the transmission of information from primary afferents to higher levels is critical to our understanding of sensory processing. In this study, we have examined phosphodiesterase 1C (Pde1c) BAC transgenic mice in which a green fluorescent protein (GFP) reporter gene reflects Pde1c expression in sensory neuron subpopulations in the dorsal root ganglia and spinal cord. Using double labeling immunofluorescence, we demonstrate GFP expression in specific subpopulations of primary sensory neurons and a distinct neuronal expression pattern within the spinal cord dorsal horn. In the dorsal root ganglia, their distribution is restricted to those subpopulations of primary sensory neurons that give rise to unmyelinated C fibers (neurofilament 200 negative). A small proportion of both non-Peptidergic (IB4-binding) and Peptidergic (CGRP immunoreactive) subclasses expressed GFP. However, GFP expression was more common in the non-Peptidergic than the Peptidergic subclass. GFP was also expressed in a subpopulation of the primary sensory neurons immunoreactive for the vanilloid receptor TRPV1 and the ATP-gated ion channel P2X3. In the spinal cord dorsal horn, GFP positive neurons were largely restricted to lamina I and to a lesser extent lamina II, but surprisingly did not coexpress markers for key neuronal populations present in the superficial dorsal horn. The expression of GFP in subclasses of nociceptors and also in dorsal horn regions densely innervated by nociceptors suggests that Pde1c marks a unique subpopulation of nociceptive sensory neurons.
Alfredo Ribeirodasilva - One of the best experts on this subject based on the ideXlab platform.
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sympathetic sprouting and changes in nociceptive sensory innervation in the glabrous skin of the rat hind paw following partial peripheral nerve injury
The Journal of Comparative Neurology, 2006Co-Authors: Laurene D Yen, Gary J Bennett, Alfredo RibeirodasilvaAbstract:Previous studies have suggested that sympathetic sprouting in the periphery may contribute to the development and persistence of sympathetically maintained pain in animal models of neuropathic pain. In the present study, we examined changes in the cutaneous innervation in rats with a chronic constriction injury to the sciatic nerve. At several periods postinjury, hind paw skin was harvested and processed by using a monoclonal antibody against dopamine-beta-hydroxylase to detect sympathetic fibers and a polyclonal antibody against calcitonin gene-related peptide to identify Peptidergic sensory fibers. We observed migration and branching of sympathetic fibers into the upper dermis of the hind paw skin, where they were normally absent. This migration was first detected at 2 weeks, peaked at 4-6 weeks, and lasted for at least 20 weeks postlesion. At 8 weeks postlesion, there was a dramatic increase in the density of Peptidergic fibers in the upper dermis. Quantification revealed that densities of Peptidergic fibers 8 weeks postlesion were significantly above levels in sham animals. The ectopic sympathetic fibers did not innervate blood vessels but formed a novel association and wrapped around sprouted Peptidergic nociceptive fibers. Our data show a long-term sympathetic and sensory innervation change in the rat hind paw skin after the chronic constriction injury. This novel fiber arrangement after nerve lesion may play an important role in the development and persistence of sympathetically maintained neuropathic pain after partial nerve lesions.
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transient loss of terminals from non Peptidergic nociceptive fibers in the substantia gelatinosa of spinal cord following chronic constriction injury of the sciatic nerve
Neuroscience, 2006Co-Authors: Andrea L Bailey, Alfredo RibeirodasilvaAbstract:It is well known that following peripheral nerve injury, there are numerous changes in neurotransmitter and neuropeptide expression in the superficial dorsal horn, the dorsal root ganglion and the periphery. Of particular interest are the relative contributions of two sub-types of unmyelinated C-fibers in the initiation and maintenance of chronic pain, the Peptidergic, and the non-Peptidergic. Evidence gathered in recent years has led researchers to believe that the non-Peptidergic nociceptive primary afferents are functionally distinct from their Peptidergic counterpart. For our study, we used a well-established animal model of constriction neuropathy (the Kruger model) and studied Wistar rats at 5, 7, 10, 15 and 21 days after nerve lesion caused by the application of a fixed-diameter polyethylene cuff to the left sciatic nerve. Animals were assessed for the onset and evolution of mechanical allodynia using calibrated von Frey filaments and were additionally tested for thermal (heat and cold) hypersensitivity. Immunocytochemical detection of calcitonin gene-related peptide (CGRP) and isolectin B4 (IB4) binding was used to visualize the dorsal horn distribution of the boutons from the Peptidergic and non-Peptidergic fibers respectively. Using confocal microscopy and image analysis, we detected a significant decrease in the density of IB4-labeled boutons, ipsilateral to the lesion, at seven and 10 days following nerve injury. The density of IB4-labeled varicosities retuned to control levels by 15 days. There were no significant changes in the density of CGRP-labeled varicosities at all time points examined. Applying electron microscopy, we initially detected degenerative changes in the central elements of type I glomeruli and then a considerable reduction in their number followed by recovery at 15 days post-lesion. As the central boutons of type Ia represent varicosities from the fibers which bind IB4, the ultrastructural changes confirmed that there was a bona fide transient loss of varicosities, not simply a loss of IB4 binding. These data indicate that, in this animal model, morphological changes in the nociceptive C-fiber input of the rat dorsal horn are restricted to the non-Peptidergic sub-population and are transient in nature. Furthermore, such changes do not correlate with the time-course of the allodynia.