Somatic Afferent Stimulation Research Articles

Peculiarities of the synaptic adaptation of the intermediate neurons of the thoracic segments of the spinal cord by cutaneous, muscle, and visceral afferents

The responses of the interneurons of the thoracic segments of the spinal cord to stimulation of the intercostal and splanchnic nerves were studied on decerebrated and narcotized cats. It was established that the neurons of different layers of the gray matter (according to Rexed) differ substantially in type of afferent inputs. Cells in laminae I–III and IV are activated chiefly by somatic afferents: primarily high-threshold in laminae I–III and low-threshold in lamina IV. The neurons of lamina V and most of the neurons of laminae VII and VIII respond to stimulation of high-threshold somatic afferents (cutaneous fibers of the Aδ group and muscle afferents of groups II and III), as well as visceral afferents of group Aγδ, conducting impulses at a rate of 9–35 m/sec. Cells of laminae VII and VIII, monosynaptically activated by muscle afferents of group I, do not respond to stimulation of the visceral afferents. The peculiarities of the "functional" laminar organization of the thoracic segments of the spinal cord are discussed.

Release of a humoral vasodilator substance during neurogenic vasodilatation.

ARTICLESRelease of a humoral vasodilator substance during neurogenic vasodilatationDR Ballard, FM Abboud, and HE MayerDR Ballard, FM Abboud, and HE MayerPublished Online:01 Nov 1970https://doi.org/10.1152/ajplegacy.1970.219.5.1451MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByThe pressor effect of angiotensin-(1-7) in the rat rostral ventrolateral medulla involves multiple peripheral mechanismsClinics, Vol. 68, No. 2Role of nitrosyl factors in the hindlimb vasodilation elicited by baroreceptor afferent nerve stimulationOlga S. Possas, Alan Kim Johnson, and Stephen J. Lewis1 March 2006 | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, Vol. 290, No. 3Hypotensive effect of ANG II and ANG-(1–7) at the caudal ventrolateral medulla involves different mechanismsA. C. Alzamora, R. A. S. Santos, and M. J. Campagnole-Santos1 November 2002 | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, Vol. 283, No. 5Vasodilatation of muscle microvessels induced by somatic afferent stimulation is mediated by calcitonin gene-related peptide release in the ratNeuroscience Letters, Vol. 333, No. 2Inhibition of sympathetic cholinergic vasodilatation by a selective NPY Y2 receptor agonist in the gracilis muscle of anaesthetised dogsJournal of the Autonomic Nervous System, Vol. 68, No. 1-2Neurogenic cutaneous vasodilation in the cat forepawJournal of the Autonomic Nervous System, Vol. 37, No. 1Inhibition of carrageenan induced inflammation in the rat knee joint by substance P antagonist.Annals of the Rheumatic Diseases, Vol. 48, No. 11In search of mediators of skin vasodilation induced by transcutaneous nerve stimulation: III. Increase in plasma VIP in normal subjects and in Raynaud's DiseaseGeneral Pharmacology: The Vascular System, Vol. 15, No. 2In search of mediators of skin vasodilation induced by transcutaneous nerve stimulation: IV. In vitro bioassay of the vasoinhibitory activity of sera from patients suffering from peripheral ischaemiaGeneral Pharmacology: The Vascular System, Vol. 15, No. 2Interaction of Cardiovascular Reflexes in Circulatory Control1 January 2011Cardiovascular Adjustments to Thermal Stress1 January 2011In search of mediators of skin vasodilation induced by transcutaneous nerve stimulation: I. Failure to block the response by antagonists of endogenous vasodilatorsGeneral Pharmacology: The Vascular System, Vol. 14, No. 6Dopamine as a postganglionic autonomic neurotransmitterNeuroscience, Vol. 7, No. 1Adenosine triphosphate-evoked vascular changes in human skin: Mechanism of actionEuropean Journal of Pharmacology, Vol. 76, No. 4Cholinergic and Purinergic Regulation of Blood Vessels1 January 2011EVIDENCE FOR DOPAMINERGIC VASODILATOR INNERVATION OF THE CANINE PAW PAD19 July 2012 | British Journal of Pharmacology, Vol. 67, No. 3Substance P as neurogenic mediator of antidromic vasodilation and neurogenic plasma extravasationNaunyn-Schmiedeberg's Archives of Pharmacology, Vol. 310, No. 2Components of the hemodynamic response to elevated cerebrospinal fluid pressureAmerican Heart Journal, Vol. 95, No. 1Neurogenic vasodilatationGeneral Pharmacology: The Vascular System, Vol. 9, No. 4AUTONOMIC NEUROEFFECTOR JUNCTIONS—REFLEX VASODILATATION OF THE SKINJournal of Investigative Dermatology, Vol. 69, No. 1REFLEX CONTROL OF THE CUTANEOUS VASCULATUREJournal of Investigative Dermatology, Vol. 69, No. 1Possible feed-back inhibition of noradrenaline release by purine compoundsNaunyn-Schmiedeberg's Archives of Pharmacology, Vol. 297, No. 1Reflex control of the peripheral circulationProgress in Cardiovascular Diseases, Vol. 18, No. 5Pharmacology of pulmonary blood vesselsPharmacology & Therapeutics. Part B: General and Systematic Pharmacology, Vol. 2, No. 2Purinergic TransmissionA VASODILATOR INNERVATION TO THE CENTRAL ARTERY OF THE RABBIT EAR19 July 2012 | British Journal of Pharmacology, Vol. 52, No. 1Reflex regulation of peripheral blood flow during lung hyperinflationThe American Journal of Cardiology, Vol. 29, No. 5Molecular Inflammation Of The SkinJournal of Investigative Dermatology, Vol. 57, No. 4 More from this issue > Volume 219Issue 5November 1970Pages 1451-1457 Copyright & PermissionsCopyright © 1970 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1970.219.5.1451PubMed5473134History Published online 1 November 1970 Published in print 1 November 1970 Metrics

Effect of reflexes of somatic afferents on the adrenergic outflow to the stomach in the cat.

AbstractThe adrenergic activity to the stomach in cats anesthetized with chloralose was modified by electric stimulation of somatic afferent nerves. Electric stimulation of “somatic pressor” afferents promptly elicited inhibitory responses of stomach contractions which contractions were, in turn, dependent on cholinergic nervous activity. However, in the absence of such cholinergic activity, corresponding somatic afferent stimulation had only an insignificant effect on the stomach, despite a considerable myogenic activity, suggesting that the inhibitory adrenergic nervous mechanism preferentially operated by interfering with the cholinergic nervous activity.—Activation of “somatic depressor” afferents, on the other hand, suppressed the prevailing supply, if any, of adrenergic nervous activity to the stomach, which could result in augmentation of vagally induced gastric motor responses. Similar effects were obtained also after spinal cord transection indicating that the “somatic depressor” afferents made propriospinal reflex connections with the sympathetic outflow to the stomach.

Role of the sympathetic nervous system in hemorrhage.

Role of the sympathetic nervous system in hemorrhage.

REFLEX INFLUENCE OF "SOMATIC PRESSOR AND DEPRESSOR AFFERENTS" ON RESISTANCE AND CAPACITANCE VESSELS AND ON TRANSCAPILLARY FLUID EXCHANGE.

AbstractJohansson, B., O. Lundgren and S. Mellander. Reflex influence of “somatic pressor and depressor afferents” on resistance and capacitance vessels and on Tran capillary fluid exchange. Acta physiol. scand. 1964. 62. 280–286. — The reflex circulatory effects of afferent somatic nerve stimulation were studied in the different consecutive vascular sections in skeletal muscle and intestine. In skeletal muscle the “somatic pressor reflex” elicited constriction of resistance and capacitance vessels and increased the pre‐/postcapillary resistance ratio while precapillary sphincter tone was unchanged. In the intestine there was reflex constriction of capacitance and precapillary sphincter vessels but only transient changes in the resistance function. In a situation of increased vasoconstrictor fiber activity produced by carotid occlusion stimulation of “somatic depressor afferents” elicited dilatation of resistance and capacitance vessels in both skeletal muscle and intestine. Carotid occlusion produced continuous absorption of fluid from the extravascular space in skeletal muscle due to a fall in capillary pressure. A superimposed stimulation of somatic depressor afferents was able to restore capillary pressure to the control level despite incomplete restoration of total resistance and capacitance functions. A dilatation of precapillary sphincters occurred in intestine but apparently not in skeletal muscle during the somatic depressor reflex.

Effects of visceral and somatic afferent nerve stimulation on intra-abdominal pressure reflex of pelvic nerve origin

Effects of excitation of visceral and somatic nerve afferents on the intra-abdominal pressure reflex produced by pelvic nerve stimulation were studied in cats. Stimulation of vagus, splanchnic and somatic mixed and skin nerves mostly depressed this reflex. A similar inhibitory interaction was obtained by stimulating branches of the pelvic nerve itself. From hind-limb nerves, inhibition of the reflex was effected by excitation of Group III and probably high-threshold Group II fibers. Judging from the threshold voltage for inhibitory action, the same was considered to be true for the remaining nerves examined. The interaction appeared to occur extensively in the central pathways of the reflex, but the principal place of blocking varied with the kind of nerves stimulated. Depression of the reflex following cranial and brachial nerve stimulations appeared to be mostly dependent upon increased supraspinal inhibition or occulusion of the bulbar reflex center. On the other hand, the study of hind limb afferents presented evidence that the motoneuron pool for the abdominal muscles could also be suppressed directly having a short latency.

Longitudinal conduction systems serving spinal and brain-stem coordination.

Longitudinal conduction systems serving spinal and brain-stem coordination.

Blood pressure responses to stimulation of somatic afferents

Blood pressure responses to stimulation of somatic afferents

Visceral pain evoked by intra-arterial injection of substance P.

IT has been demonstrated1,2 that the intra-arterial injection of 1–2 µgm. of bradykinin into various organs throughout the body of the cat and dog will evoke vocalization and the other events which comprise the pseudo-affective reflexes which Woodworth and Sherrington3 obtained by electrical stimulation of somatic and splanchnic afferents in the decerebrate cat. The receptors concerned are the free-branching unmyelinated terminals of paravascular nerves which are found in the connective tissue space surrounding capillaries in the organs tested4.

On the response of the vasomotor system to somatic afferent nerve stimulation, and the effects of anaesthesia and curare thereon

1. Single or low frequency repetitive stimulation applied to the auricular or saphenous nerves in the anaesthetized rabbit causes a drop in the mean systemic blood pressure due to an inhibition of the tonic sympathetic discharge of the vasomotor centre. More intense stimulation may abolish the response and a further increase will produce a pressor reaction.

Distribution of responses to somatic afferent stimuli in the diencephalon of the cat under chloralose anesthesia

Electrical responses to somatic afferent stimulation were studied with the aim of determining their distribution with respect to morphological groupings of the cat diencephalon in two hundred twelve histologically analyzed explorations. In addition to the well-known tactile projection to the ventrobasal (VB) complex, nontactile somatic responses of longer latency were found with reasonable consistency in the centrum medianum-parafascicular (CM) complex, posterior complex, central commissural system, ventrolateral complex, and nucleus ruber, as well as in several subthalamic structures for which the findings were some-what less secure. Some evidence is presented suggesting that the CM response may be excited by the spinothalamic system and that responses in this region differ from those in the classical lemniscal pathway (VB) in modality and somatotopic representation, latency, spinal pathway, and anesthetic susceptibility.

TRANSCALLOSAL RESPONSE IN SOMATIC AREA II

A compound response was evoked in somatic area II by electrical stimula-tion to contralateral somatic II of the cerebral cortex of cat: surface positive deflection (P) prior to negative deflection (D) followed by a prolonged positive deflection (A). A spike sequence can also be recorded before and on the rising limb of component P.Studies were made of excitability characteristics determined with the use of paired identical stimuli at various intervals and recurrence rates. The effects. of local cortical application of potassium cyanide and strychnine sulfate were evaluated. Intracortical recording was made with approximately 10μ pipette electrodes. Interaction studies were also made by means of various combinations, of paired stimuli at different intervals.It is suggested from these experiments that component P represents the product of postsynaptic activity, being largely produced by the same cortical elements as the postsynaptic positive components of the primary response evoked. by contralateral and ipsilateral somatic afferent nerve stimulation. It is also suggested that component D is of similar origin as the dendritic response evoked by topical stimulation. Component A is considered to represent the activity of neurones different from those which occasion component P.

Central influences on spinal afferent conduction.

Central influences on spinal afferent conduction.