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János Szolcsányi - One of the best experts on this subject based on the ideXlab platform.

  • Release of somatostatin and its role in the mediation of the anti-inflammatory effect induced by Antidromic Stimulation of sensory fibres of rat sciatic nerve.
    British journal of pharmacology, 1998
    Co-Authors: János Szolcsányi, Zsuzsanna Helyes, Gábor Oroszi, József Németh, Erika Pintér
    Abstract:

    1 The effect of Antidromic Stimulation of the sensory fibres of the sciatic nerve on inflammatory plasma extravasation in various tissues and on cutaneous vasodilatation elicited in distant parts of the body was investigated in rats pretreated with guanethidine (8 mg kg−1, i.p.) and pipecuronium (200 μg kg−1, i.v.). 2 Antidromic sciatic nerve Stimulation with C-fibre strength (20 V, 0.5 ms) at 5 Hz for 5 min elicited neurogenic inflammation in the innervated area and inhibited by 50.3±4.67% the development of a subsequent plasma extravasation in response to similar Stimulation of the contralateral sciatic nerve. Stimulation at 0.5 Hz for 1 h also evoked local plasma extravasation and inhibited the carrageenin-induced (1%, 100 μl s.c.) cutaneous inflammation by 38.5±10.0% in the contralateral paw. Excitation at 0.1 Hz for 4 h elicited no local plasma extravasation in the stimulated hindleg but still reduced the carrageenin-induced oedema by 52.1±9.7% in the paw on the contralateral side. 3 Plasma extravasation in the knee joint in response to carrageenin (2%, 200 μl intra-articular injection) was diminished by 46.1±12.69% and 40.9±4.93% when the sciatic nerve was stimulated in the contralateral leg at 0.5 Hz for 1 h or 0.1 Hz for 4 h, respectively. 4 Stimulation of the peripheral stump of the left vagal nerve (20 V, 1 ms, 8 Hz, 10 min) elicited plasma extravasation in the trachea, oesophagus and mediastinal connective tissue in rats pretreated with atropine (2 mg kg−1, i.v.), guanethidine (8 mg kg−1, i.p.) and pipecuronium (200 μg kg−1, i.v.). These responses were inhibited by 37.8±5.1%, 49.7±9.9% and 37.6±4.2%, respectively by Antidromic sciatic nerve excitation (5 Hz, 5 min) applied 5 min earlier. 5 Pretreatment with polyclonal somatostatin antiserum (0.5 ml/rat, i.v.) or the selective somatostatin depleting agent cysteamine (280 mg kg−1, s.c.) prevented the anti-inflammatory effect of sciatic nerve Stimulation (5 Hz, 5 min) on a subsequent neurogenic plasma extravasation of the contralateral paw skin. The inhibitory effect of Antidromic sciatic nerve excitation on plasma extravasation in response to vagal nerve Stimulation was also prevented by somatostatin antiserum pretreatment. 6 Cutaneous blood flow assessment by laser Doppler flowmetry indicated that Antidromic vasodilatation induced by sciatic nerve Stimulation was not inhibited by excitation of the sciatic nerve of the contralateral leg (1 Hz, 30 min) or by somatostatin (10 μg/rat, i.v.) injection. 7 Plasma levels of somatostatin increased more than 4 fold after Stimulation of both sciatic nerves (5 Hz, 5 min) but the stimulus-evoked increase was not observed in cysteamine (280 mg kg−1, s.c.) pretreated rats. 8 These results suggest that somatostatin released from the activated sensory nerve terminals mediates the systemic anti-inflammatory effect evoked by stimulating the peripheral stump of the sciatic nerve. British Journal of Pharmacology (1998) 123, 936–942; doi:10.1038/sj.bjp.0701685

  • Systemic anti-inflammatory effect induced by Antidromic Stimulation of the dorsal roots in the rat☆
    Neuroscience letters, 1996
    Co-Authors: Erika Pintér, János Szolcsányi
    Abstract:

    Neurogenic inflammation and other local efferent functions of the capsaicin-sensitive nerve endings is well established. Here, we describe evidence for a systemic neurogenic anti-inflammatory effect initiated in the rat by this local response. A preceding local neurogenic inflammation induced by Antidromic Stimulation of lumbar dorsal roots inhibited a subsequent inflammatory response due to Antidromic Stimulation of the contralateral dorsal roots or evoked by subplantar carrageenin injection or instillation of capsaicin solution into the eye. Initiation of these anti-inflammatory responses were prevented by degeneration of the capsaicin-sensitive afferents after perineural capsaicin pre-treatment, but not by bilateral adrenalectomy. These results demonstrate an unorthodox new type of neurohumoral regulatory mechanism of sensory fibres and provide a possible mode of action for the anti-inflammatory effect of counter-irritation and acupuncture.

  • Plasma extravasation in the skin and pelvic organs evoked by Antidromic Stimulation of the lumbosacral dorsal roots of the rat.
    Neuroscience, 1995
    Co-Authors: Erika Pintér, János Szolcsányi
    Abstract:

    Electrical Stimulation of the distal stump of cut peripheral nerves is a commonly accepted way to evoke neurogenic inflammation. Nevertheless, the modulatory effect of biogenic amines and vasoactive peptides released from efferent fibres can be excluded only if the dorsal roots are stimulated. The present study was focussed to investigate plasma extravasation in the appropriate skin and mucosal areas as well as in the genito-urinary organs in response to Antidromic Stimulation of the lumbar and sacral dorsal roots of the rat. Plasma extravasation was detected by quantitative measurement of the accumulated Evans Blue tracer in tissue pieces. Two unilateral posterior roots were stimulated simultaneously (20 V, 0.5 ms, 5 Hz, 5 min) in each anaesthetized rat. Intensive blueing response occurred in the following tissues: plantar glabrous skin, L4-L5 (L6); dorsum of the hindpaw and ankle joint, L2-L4; ventral surface of the thigh, L2-L4 (L1); abdominal skin, L1-L4; caudal nipples, L1-L2; root of the tail, S1 orifice of the vagina, S1 (L6); vagina, L2-L3, L5-S1; cervix and corpus uteri, L2-L3, L5-S1; lower two-thirds of the uterine horns, L1-L3; urinary bladder, L1-L3, L6-S1; rectum, L5-S1; scrotum (dorsal surface and lower pole), L6-S1; scrotum (ventral surface), L3-L5. No significant dye accumulation was observed in the muscles, testicles, vas deferens and prostate. Plasma extravasation caused by Antidromic activation of the dorsal roots was absent or highly reduced after systemic capsaicin pretreatment of the rats. Neurogenic inflammation evoked by Antidromic Stimulation of the dorsal roots makes this method suitable for mapping the organs where capsaicin-sensitive sensory nerve endings exert their "efferent functions". This first functional description of segmental innervation of capsaicin-sensitive afferent fibres is in agreement with retrograde tracing studies and immunohistochemical localization of substance P in the dorsal root ganglia and peripheral tissues.

Erika Pintér - One of the best experts on this subject based on the ideXlab platform.

  • Release of somatostatin and its role in the mediation of the anti-inflammatory effect induced by Antidromic Stimulation of sensory fibres of rat sciatic nerve.
    British journal of pharmacology, 1998
    Co-Authors: János Szolcsányi, Zsuzsanna Helyes, Gábor Oroszi, József Németh, Erika Pintér
    Abstract:

    1 The effect of Antidromic Stimulation of the sensory fibres of the sciatic nerve on inflammatory plasma extravasation in various tissues and on cutaneous vasodilatation elicited in distant parts of the body was investigated in rats pretreated with guanethidine (8 mg kg−1, i.p.) and pipecuronium (200 μg kg−1, i.v.). 2 Antidromic sciatic nerve Stimulation with C-fibre strength (20 V, 0.5 ms) at 5 Hz for 5 min elicited neurogenic inflammation in the innervated area and inhibited by 50.3±4.67% the development of a subsequent plasma extravasation in response to similar Stimulation of the contralateral sciatic nerve. Stimulation at 0.5 Hz for 1 h also evoked local plasma extravasation and inhibited the carrageenin-induced (1%, 100 μl s.c.) cutaneous inflammation by 38.5±10.0% in the contralateral paw. Excitation at 0.1 Hz for 4 h elicited no local plasma extravasation in the stimulated hindleg but still reduced the carrageenin-induced oedema by 52.1±9.7% in the paw on the contralateral side. 3 Plasma extravasation in the knee joint in response to carrageenin (2%, 200 μl intra-articular injection) was diminished by 46.1±12.69% and 40.9±4.93% when the sciatic nerve was stimulated in the contralateral leg at 0.5 Hz for 1 h or 0.1 Hz for 4 h, respectively. 4 Stimulation of the peripheral stump of the left vagal nerve (20 V, 1 ms, 8 Hz, 10 min) elicited plasma extravasation in the trachea, oesophagus and mediastinal connective tissue in rats pretreated with atropine (2 mg kg−1, i.v.), guanethidine (8 mg kg−1, i.p.) and pipecuronium (200 μg kg−1, i.v.). These responses were inhibited by 37.8±5.1%, 49.7±9.9% and 37.6±4.2%, respectively by Antidromic sciatic nerve excitation (5 Hz, 5 min) applied 5 min earlier. 5 Pretreatment with polyclonal somatostatin antiserum (0.5 ml/rat, i.v.) or the selective somatostatin depleting agent cysteamine (280 mg kg−1, s.c.) prevented the anti-inflammatory effect of sciatic nerve Stimulation (5 Hz, 5 min) on a subsequent neurogenic plasma extravasation of the contralateral paw skin. The inhibitory effect of Antidromic sciatic nerve excitation on plasma extravasation in response to vagal nerve Stimulation was also prevented by somatostatin antiserum pretreatment. 6 Cutaneous blood flow assessment by laser Doppler flowmetry indicated that Antidromic vasodilatation induced by sciatic nerve Stimulation was not inhibited by excitation of the sciatic nerve of the contralateral leg (1 Hz, 30 min) or by somatostatin (10 μg/rat, i.v.) injection. 7 Plasma levels of somatostatin increased more than 4 fold after Stimulation of both sciatic nerves (5 Hz, 5 min) but the stimulus-evoked increase was not observed in cysteamine (280 mg kg−1, s.c.) pretreated rats. 8 These results suggest that somatostatin released from the activated sensory nerve terminals mediates the systemic anti-inflammatory effect evoked by stimulating the peripheral stump of the sciatic nerve. British Journal of Pharmacology (1998) 123, 936–942; doi:10.1038/sj.bjp.0701685

  • Systemic anti-inflammatory effect induced by Antidromic Stimulation of the dorsal roots in the rat☆
    Neuroscience letters, 1996
    Co-Authors: Erika Pintér, János Szolcsányi
    Abstract:

    Neurogenic inflammation and other local efferent functions of the capsaicin-sensitive nerve endings is well established. Here, we describe evidence for a systemic neurogenic anti-inflammatory effect initiated in the rat by this local response. A preceding local neurogenic inflammation induced by Antidromic Stimulation of lumbar dorsal roots inhibited a subsequent inflammatory response due to Antidromic Stimulation of the contralateral dorsal roots or evoked by subplantar carrageenin injection or instillation of capsaicin solution into the eye. Initiation of these anti-inflammatory responses were prevented by degeneration of the capsaicin-sensitive afferents after perineural capsaicin pre-treatment, but not by bilateral adrenalectomy. These results demonstrate an unorthodox new type of neurohumoral regulatory mechanism of sensory fibres and provide a possible mode of action for the anti-inflammatory effect of counter-irritation and acupuncture.

  • Plasma extravasation in the skin and pelvic organs evoked by Antidromic Stimulation of the lumbosacral dorsal roots of the rat.
    Neuroscience, 1995
    Co-Authors: Erika Pintér, János Szolcsányi
    Abstract:

    Electrical Stimulation of the distal stump of cut peripheral nerves is a commonly accepted way to evoke neurogenic inflammation. Nevertheless, the modulatory effect of biogenic amines and vasoactive peptides released from efferent fibres can be excluded only if the dorsal roots are stimulated. The present study was focussed to investigate plasma extravasation in the appropriate skin and mucosal areas as well as in the genito-urinary organs in response to Antidromic Stimulation of the lumbar and sacral dorsal roots of the rat. Plasma extravasation was detected by quantitative measurement of the accumulated Evans Blue tracer in tissue pieces. Two unilateral posterior roots were stimulated simultaneously (20 V, 0.5 ms, 5 Hz, 5 min) in each anaesthetized rat. Intensive blueing response occurred in the following tissues: plantar glabrous skin, L4-L5 (L6); dorsum of the hindpaw and ankle joint, L2-L4; ventral surface of the thigh, L2-L4 (L1); abdominal skin, L1-L4; caudal nipples, L1-L2; root of the tail, S1 orifice of the vagina, S1 (L6); vagina, L2-L3, L5-S1; cervix and corpus uteri, L2-L3, L5-S1; lower two-thirds of the uterine horns, L1-L3; urinary bladder, L1-L3, L6-S1; rectum, L5-S1; scrotum (dorsal surface and lower pole), L6-S1; scrotum (ventral surface), L3-L5. No significant dye accumulation was observed in the muscles, testicles, vas deferens and prostate. Plasma extravasation caused by Antidromic activation of the dorsal roots was absent or highly reduced after systemic capsaicin pretreatment of the rats. Neurogenic inflammation evoked by Antidromic Stimulation of the dorsal roots makes this method suitable for mapping the organs where capsaicin-sensitive sensory nerve endings exert their "efferent functions". This first functional description of segmental innervation of capsaicin-sensitive afferent fibres is in agreement with retrograde tracing studies and immunohistochemical localization of substance P in the dorsal root ganglia and peripheral tissues.

Yan Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Somatostatin inhibits activation of dorsal cutaneous primary afferents induced by Antidromic Stimulation of primary afferents from an adjacent thoracic segment in the rat
    Brain research, 2008
    Co-Authors: Yuan Guo, Hui-sheng Wang, Dong-yuan Cao, Joel G. Pickar, Fanrong Yao, Qi Zhang, Yan Zhao
    Abstract:

    Abstract To investigate the effect of somatostatin on the cross-excitation between adjacent primary afferent terminals in the rats, we recorded single unit activity from distal cut ends of dorsal cutaneous branches of the T10 and T12 spinal nerves in response to Antidromic Stimulation of the distal cut end of the T11 dorsal root in the presence and absence of somatostatin and its receptor antagonist applied to the receptive field of the recorded nerve. Afferent fibers were classified based upon their conduction velocity. Mean mechanical thresholds decreased and spontaneous discharge rates increased significantly in C and Aδ but not Aβ fibers of the T10 and T12 spinal nerves in both male and female rats following Antidromic electrical Stimulation (ADES) of the dorsal root from adjacent spinal segment (DRASS) indicating cross-excitation of thin fiber afferents. The cross-excitation was not significantly different between male and female rats. Microinjection of somatostatin into the receptive field of recorded units inhibited the cross-excitation. This inhibitory effect, in turn, was reversed by the somatostation receptor antagonist cyclo-somatostatin (c-SOM). Application of c-SOM alone followed by ADES of DRASS significantly decreased the mechanical thresholds and increased the discharge rates of C and Aδ fibers, indicating that endogenous release of somatostatin plays a tonic inhibitory role on the cross-excitation between peripheral nerves. These results suggest that somatostatin could inhibit the cross-excitation involved in peripheral hyperalgesia and have a peripheral analgesic effect.

Nikos K. Logothetis - One of the best experts on this subject based on the ideXlab platform.

  • Activation of SC during electrical Stimulation of LGN: retinal Antidromic Stimulation or corticocollicular activation?
    Magnetic resonance imaging, 2011
    Co-Authors: Yusuke Murayama, Mark Augath, Nikos K. Logothetis
    Abstract:

    We have recently used combined electroStimulation, neurophysiology, microinjection and functional magnetic resonance imaging (fMRI) to study the cortical activity patterns elicited during Stimulation of cortical afferents in monkeys. We found that Stimulation of a site in lateral geniculate nucleus (LGN) increases the fMRI signal in the regions of primary visual cortex receiving input from that site, but suppresses it in the retinotopically matched regions of extrastriate cortex. Intracortical injection experiments showed that such suppression is due to synaptic inhibition. During these experiments, we have consistently observed activation of superior colliculus (SC) following LGN Stimulation. Since LGN does not directly project to SC, the current study investigated the origin of SC activation. By examining experimental manipulations inactivating the primary visual cortex, we present here evidence that the robust SC activation, which follows the Stimulation of LGN, is due to the activation of corticocollicular pathway.

Brian Collier - One of the best experts on this subject based on the ideXlab platform.

  • Increased Acetylcholine Content Induced by Antidromic Stimulation of a Sympathetic Ganglion: A Possible Retrograde Action of Adenosine
    Journal of neurochemistry, 2002
    Co-Authors: A. Tandon, Brian Collier
    Abstract:

    Prolonged high-frequency orthodromic Stimulation of superior cervical ganglia is known to result in increased acetylcholine (ACh) synthesis and ACh content after the period of Stimulation. In a previous study, we provided evidence to suggest that adenosine acts as an extracellular signal to activate this increased ACh synthesis and we proposed that the source of that adenosine might be postsynaptic. Thus, the purpose of the present study was to test whether direct Stimulation of the post-ganglionic nerves could affect ganglionic ACh content. Antidromic conditioning of ganglia (15 Hz, 45 min) did not affect significantly their ACh content. However, if ganglia were allowed a 15-min rest period after this Antidromic conditioning, their ACh stores were increased by 20% ; a similar increase was induced by 4-Hz Stimulation before the rest period. During the 15-Hz Antidromic Stimulation, ACh release was not clearly increased above the basal level, suggesting that preganglionic nerve endings were not stimulated to an extent that could explain the increased ACh content. Orthodromic Stimulation (5 Hz) of ganglia 15 min after they had been subjected to Antidromic conditioning (15 Hz, 45 min) showed increased ACh release in comparison with that from control unconditioned ganglia. Moreover, the extra ACh released by the conditioned ganglia was quantitatively similar to the increase in the ACh stores, as if most, or all, of the additional ACh was released by preganglionic Stimulation. If the Antidromic conditioning and the rest period were done during perfusion with Ca 2+ -free medium, the ganglia did not accumulate extra ACh. The ACh content was also not changed if ganglia were conditioned in the absence of Ca 2+ but rested with normal Ca 2+ . However, ACh content was increased by 23% when the Antidromic Stimulation was done with normal Ca 2+ but the rest period was without Ca 2+ . To test the role of adenosine in this retrograde effect, the effect of nucleoside transport inhibitors was tested. Dipyridamole blocked the Antidromic Stimulation-induced increase, but nitrobenzylthioinosine did not. Overall, these results are consistent with the idea that a diffusible retrograde messenger activates ACh synthesis. The sensitivity to blockade by dipyridamole suggests that adenosine might be that signal.