Einfluss von synthetischem Bradykinin und Kallidin auf die Chemoreceptoren der Gefässe der hinteren Extremität der Katze

Summary The hindlimb of cat was separated from the body, the sciatic nerve remaining intact, The separated hindlimb was perfused through the femoral artery with tyrode solution. Synthetic bradykinin and kallidin injected into the femoral artery elicit vasoconstriction in the hindlimb, reflex on the systemic blood pressure, and stimulation of respiration. We assumed the cause of this reflex to be general sympathetic excitation through stimulation of chemoreceptor cells in the blood vessels of the hindlimb of the cat.     

Perception of olfactory and intranasal trigeminal stimuli following cutaneous electrical stimulation

Based on previous research it may be hypothesized that the perception of odorants is modified by an axon reflex emanating from trigeminal afferents activated via the skin and/or the intranasal respiratory epithelium. The present experiment investigated the effects of trigeminal cutaneous stimulation on intensity estimates of intranasal chemical stimuli. While the left nostril was stimulated chemically with olfactory and trigeminal stimulants, four regions of the face were stimulated electrically. Intensity estimates of the chemical stimuli tended to increase after cutaneous electrical stimulation which may be interpreted in terms of response priming. The effect of electrical stimulation did not differ at the 4 stimulation sites. The results argue against the hypothesis that the processing of intranasal chemical stimuli is modified peripherally by cutaneous trigeminal excitation.     

A somatotopic organization of leg afferents in the spiderCupiennius salei Keys. (Araneae,Ctenidae)

Summary Axonal anterograde degeneration after ablation of different leg segments of the spiderCupiennius salei was traced using LM-and EM-methods. The pattern of degeneration seen in cross sections of the leg nerves close to their entry into the subesophageal ganglion shows a somatotopic organization of afferents within the leg nerves coming from different leg segments. All afferents run through the ventral part of the nerve.Acknowledgment. We thank Dr E.A. Seyfarth for helpful discussions. Parts of the study were supported by the Deutsche Forschungsgemeinschaft (W.G., SFB45/A1).     

Role played in man by myelinated fibers of different diameters for the evocation of a nociceptive flex reflex and the accompanying pain sensation]

Using simultaneous recordings we have made in Man a comparative study of: the sural nerve afferent volley, the nociceptive flexor reflex of a muscle of the lower limb and the associated painful sensation. Two types of stimulations were used, a single short duration electric stimulus, and a train of electric shocks (100/sec). With a single stimulus, the nociceptive flexor reflex and the painful sensation develop only when A delta fibers are recruited. On the other hand, when the stimulations are given by trains the nociceptive flexor reflex and the painful sensation can develop with a stimulus sub-liminar to the threshold of A delta fibers, when A alpha fibers are recruited. When the stimulus activate both A alpha and A delta fibers, the flexion reflex and the pain disappear when a selective blockade of the A delta group is exerted by means of Lidocain.     

Physiologische Untersuchungen an der innervierten glatten Muskulatur der Vogelfedern (Mm. pennarum)

Summary The tension development of the smooth feather muscles of the pigeon was measured (a) on the wing in situ (b) on an isolated innervated skin preparation and (c) on an isolated muscle preparation. The contraction produced by nerve stimulation is biphasic. The second phase can be blocked by -receptor blocking agents. The mechanism of the first phase is unknown. The preparation seems very suitable for the investigation of neuromuscular transmission in smooth muscle.     

Different intrafusal fiber composition of spindles in sheep and pig extraocular muscles

Histochemical profiles of intrafusal fibers have been examined in muscle spindles of extraocular muscles of sheep and pig. Results show that in the sheep the intrafusal content presents, in addition to chain fibers, at least one bag1 and one bag2 fiber, whereas in the pig almost all the spindles are one-bag-fiber [corrected] spindles.     

Neuromuscular spindles in bovine foetuses with hereditary muscle fiber hyperplasia

Summary In cattle with genetic hyperplasia of skeletal muscle fibers, foetuses have an increased number of intrafusal muscle fibers in their neuromuscular spindles.     

Contractile properties of fast muscle preparations regenerating in slow muscle beds

Summary Mechanical evidence is presented to show that fast muscle tissue regenerating in the bed of a slow muscle, and innervated by the slow muscle nerve, has contractile properties identical to those of a slow muscle regenerating in its own bed. The results do not support the idea that regenerating fast muscles are partially resistant to the transforming effects of a slow nerve.This investigation was supported in part by NIH grants 1-RO1-NS-14033 and 1-T32-07224.     

Effets d'un inhibiteur béta-adrénergique,l'aténolol,sur l'activité efférente du nerf rénal chez le lapin

Summary Postganglionic sympathetic nerve activity (renal nerve) decreased significantly during i.v. infusion of a beta-adrenergic blocking drug, atenolol, in anesthetized rabbits. This phenomenon, at least in part reflex in nature, may contribute to the hypotensive effect of atenolol.

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Travail réalisé dans le cadre d'un contrat INSERM, ATP n^o 15.75.38.     

Motor nerve terminal defect following tenotomy

Summary Post-tetanic potentiation and the underlying post-tetanic repetition in cat soleus muscle require normal motor nerve terminals. These indices of nerve terminal viability are depressed 10 days and absent 15 days after tenotomy of the soleus muscle.Supported in part by NIH grant NS-11948.     

Different intrafusal fiber composition of spindles in sheep and pig extraocular muscles

Summary Histochemical profiles of intrafusal fibers have been examined in muscle spindles of extraocular muscles of sheep and pig. Results show that in the sheep the intrafusal content presents, in addition to chain fibers, at least one bag₁ and one bag₂ fiber, whereas in the pig almost all the spindles are bag₁-fiber spindles.Acknowledgment. This study was supported by grants from C.N.R. and M.P.I.     

Das perfundierte Riesenaxon des Tintenfisches Eine neue Methode der Nervenphysiologie und ihre ersten Anwendungen

Summary The recently developed perfused nerve fibre technique, which consists of perfusing the interior of a squid giant fibre with artificial solutions, is described. The experimental results obtained with various perfusion fluids are discussed in relation to the theory of nerve excitation.     

Acetylcholine synthesis and its dependence on nervous activity.

The findings discussed in this paper mainly derived from studies on salivary glands, serving as model organs, indicate that the capacity to form the neurotransmitter acetylcholine, as judged by the activity of choline acetyltransferase, is influenced by the traffic of nerve impulses, as a long term effect. In the glands, choline acetyltransferase seems to be exclusively localized to the cholinergic nerves. In the postganglionic parasympathetic nerves of the glands, the activity of choline acetyltransferase decreases when the flow of secretory impulses in these nerves is abolished or reduced either by isolating the nerves from the central nervous system, surgically or pharmacologically, or by diminishing the reflex activation of the glands from the mouth. The opposite occurs when the reflex activation of the salivary glands is enhanced, i.e. the activity of choline acetyltransferase increases. Observations on various other organs are quoted in support of the view that the traffic of nerve impulses is of importance for the activity of the enzyme. An increase in choline acetyltransferase activity also occurs in some salivary glands after sympathetic denervation. This puzzling observation is discussed in relation to impulse traffic. Increased nerve impulse traffic and collateral sprouting seem to be responsible for the rapid restitution of choline acetyltransferase activity from a low level in an organ partially deprived of its cholinergic nerve supply.     

Acetylcholine synthesis and its dependence on nervous activity

Summary The findings discussed in this paper mainly derived from studies on salivary glands, serving as model organs, indicate that the capacity to form the neurotransmitter acetylcholine, as judged by the activity of choline acetyltransferase, is influenced by the traffic of nerve impulses, as a long term effect. In the glands, choline acetyltransferase seems to be exclusively localized to the cholinergic nerves. In the postganglionic parasympathetic nerves of the glands, the activity of choline acetyltransferase decreases when the flow of secretory impulses in these nerves is abolished or reduced either by isolating the nerves from the central nervous system, surgically or pharmacologically, or by diminishing the reflex activation of the glands from the mouth. The opposite occurs when the reflex activation of the salivary glands is enhanced, i.e. the activity of choline acetyltransferase increases. Observations on various other organs are quoted in support of the view that the traffic of nerve impulses is of importance for the activity of the enzyme. An increase, in choline acetyltransferase activity also occurs in some salivary glands after sympathetic denervation. This puzzling observation is discussed in relation to impulse traffic. Increased nerve impulse traffic and collateral sprouting seem to be responsible for the rapid restitution of choline acetyltransferase activity from a low level in an organ partially deprived of its cholinergic nerve supply.     

Tachykinins and their functions in the gastrointestinal tract

In the gastrointestinal tract, tachykinins are peptide neurotransmitters in nerve circuits that regulate intestinal motility, secretion, and vascular functions. Tachykinins also contribute to transmission from spinal afferents that innervate the gastrointestinal tract and have roles in the responses of the intestine to inflammation. Tachykinins coexist with acetylcholine, the primary transmitter of excitatory neurons innervating the muscle, and act as a co-neurotransmitter of excitatory neurons. Excitatory transmission is mediated through NK1 receptors (primarily on interstitial cells of Cajal) and NK2 receptors on the muscle. Tachykinins participate in slow excitatory transmission at neuro-neuronal synapses, through NK1 and NK3 receptors, in both ascending and descending pathways affecting motility. Activation of receptors (NK1 and NK2) on the epithelium causes fluid secretion. Tachykinin receptors on immune cells are activated during inflammation of the gut. Finally, tachykinins are released from the central terminals of gastrointestinal afferent neurons in the spinal cord, particularly in nociceptive pathways. Received 24 March 2007; received after revision 30 August 2007; accepted 14 September 2007     

Ultrastructure of muscle spindles in C57BL/6J dy2J/dy2J dystrophic mice.

The sensory organs of skeletal muscles, the muscle spindles, were examined using electron microscopy in dy2J/dy2J dystrophic mice. Despite widespread damage to the extrafusal (skeletomotor) fibres the intrafusal (spindle) fibres appeared normal and seemed resistant to the aetiological factors for murine dystrophy.     

Nachweis einer reflektorischen Natur der Jodazetat-Miosis

Summary Intravenous administration of iodoacetate (20 mg/kg) produces in cats a transient miosis. This is shown to be a reflex constriction elicited by an excitatory action of iodoacetate on the retina.     

Lamellated sensory nerve endings in guinea-pig adrenals

Summary Lamellated sensory nerve endings were observed in the adrenal gland of guinea-pigs located at the corticomedullary junction close to venous blood vessels. We suggest that they form the afferents of a system contributing to a local regulation of adrenal blood flow.     

Heterogeneous effects of sinusoidal muscular stretching on frequency grams of primary endings due to stimulation of static gamma axons]

The action of sinusoidal stretching at 1,5 Hz on primary ending frequencygrams due to repetitive stimulation of static gamma axons has been studied, in nembutalized cats, on flexor hallucis longus muscle spindles. Whenever, in static conditions, driving is elicited by the repetitive stimulation of gamma axons, the elementary components of the frequencygrams increase in amplitude during muscle stretch. This effect is not observed when the stimulation of the gamma axons gives a regular acceleration of the primary endings without "driving".     

The action of substance P on mesencephalic reticular and substantia nigral neurones of the rat.

Extracellular recordings were made from neurones in the mesencephalic reticular formation and substantianigra of the rat which was anaesthetized with urethane 1.5-2 g/kg i.p. Out of 44 cells tested 42 were excited by Substance P applied iontophoretically and in some cases this excitation was rapid. Evidence is presented for Substance P as a putative excitatory transmitter onto reticular and nigral neurones possibly released from primary sensory afferents.