Inhibition of shivering obtained by peripheral stimulation

Résumé La stimulation de la patte chez le chien anesthésié, inhibe l'activité musculaire enregistrée pendant les attaques de frisson. Cet effet peut dépendre de l'action inhibitrice des influx nerveux agissant sur l'hypothalamus ou même sur la formation réticulaire, et peut se distinguer des influences inhibitrices d'origine médullaire qu'on observe quand la patte est stimulée en dehors des attaques de frisson.

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Supported by grants from the British Council and the Consejo Nacional de Investigaciones Cientificas y Técnicas, Argentina.     

Inflammatory factors produced by sensitized guinea-pig peripheral blood lymphocytes

Summary The supernatants obtained from stimulated tuberculin-sensitive guinea-pig peripheral blood lymphocytes contain factors that induce a cutaneous inflammatory response in normal guinea-pigs similar to the tuberculin reaction and inhibit the migration of normal guinea-pigs peritoneal exudate cells. There appears to be a correlation between the presence of in vitro migration inhibitory activity and inflammatory activity in vivo.     

Responses to stimulation of the peripheral end of the right splanchnic nerve in the conscious calf

Summary The ratio at which adrenaline and noradrenaline are released from the adrenal medulla in response to stimulation of the splanchnic nerve has been established in the conscious calf. The proportion of adrenaline: noradrenaline was closely similar to that in which the 2 amines are stored in the gland and released in response to other stimuli in conscious, but not anaesthetized, calves.Acknowledgments. This work has been supported by a grant from the Agricultural Research Council, and we are also indebted to Dr D.M. Burley (Ciba) for his continued support. It is a pleasure to acknowledge the skilled technical assistance provided by Mr P.M.M. Bircham.     

Monosynaptic inhibition of thalamic neurons produced by stimulation of the substantia nigra

Summary Electrical stimulation to the substantia nigra (Pars reticulata) produced a monosynaptic inhibition of the neurons of the ventromedial necleus of the thalamus in anesthetized cats.     

Generalized inhibition of spinal reflexes induced by cutaneous nerve stimulation in unrestrained cats

Riassunto Nell'animale integro non anestetizzato la stimolazione a bassa frequenza delle fibre cutanee del gruppo II produce una riduzione generalizzata del tono posturale e dei riflessi spinali mono- e polisinaptici, che si accompagna di solito, ma non necessariamente, ad un quadro di sincronizzazione elettroencefalografica. In particolari condizioni sperimentali la stimolazione cutanea suddetta può anche precipitare il quadro di sonno desincronizzato.

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This investigation was supported by PHS research grant B-2990 from the National Institute of Neurological Diseases and Blindness, N.I.H., Public Health Service (U.S.A.).     

Modifications of the vestibular nerve activity by stimulation of the efferent vestibular system

Riassunto La stimolazione elettrica della zona nucleare vestibolare in vicinanza del nucleo di Deiters (dove presumibilmente originano le fibre efferenti vestibolari) è seguita, dopo un periodo di latenza pressochè costante (22–32 msec), dalla comparsa di potenziali bioelettrici nel nervo vestibolare controlaterale.     

Study of the cortical field potentials produced by weak light stimulation in adult rabbits]

On a chronic preparation of an adult Rabbit, the cortical visual evoked response, produced by a weak luminous stimulation activating only the scotopic system is characterized by the suppression of the early surface-positive phase and by a lengthening of the latencies of the following deflection. The profile of the fields of potential corresponding to the various defletions in relation to the depth, has been investigated.     

Electromyographic responses elicited by cutaneous and mixed nerve stimulation in human tibialis anterior muscle

The rectified and averaged myoelectrical responses of the anterior tibial muscle to stimulation of the posterior tibial, peroneal and sural nerves at the ankle were recorded during a weak isometric contraction in man. The stimulation of the posterior tibial nerve elicited two excitatory phases (short and long latency excitations) at 40 ms and 78 ms latencies, respectively, separated by a phase of reduced activity. With peroneal and sural nerve stimulation such triphasic responses were less consistent; only a monophasic inhibitory response occurred in some recordings. These results indicate that well-identifiable responses with distinct latencies can be obtained in human leg muscle with cutaneous and mixed nerve stimulation distal to the muscle.     

Adrenergic nerve endings in the peripheral autonomic ganglion

Zusammenfassung Mittels elektronenmikroskopischer Untersuchungen wird die Anwesenheit adrenergischer Nervenendigungen im Ganglion hypogastricum des Meerschweinchens bewiesen.     

Reflex motility of the stomach evoked by electrical stimulation of the hepatic vagus nerve

Summary Electrical stimulation of the cranial end of the cut hepatic branch of the vagus nerve produced an increase in the motility of the empty stomach in the rat, whereas systemic injection of insulin produced a gradual increase in the motility.Acknowledgment. The authors are indebted to Dr K. Yamaguchi and Prof. A. Niijima for their encouragement of the project.     

Electromyographic responses elicited by cutaneous and mixed nerve stimulation in human tibialis anterior muscle

Summary The rectified and averaged myoelectrical responses of the anterior tibial muscle to stimulation of the posterior tibial, peroneal and sural nerves at the ankle were recorded during a weak isometric contraction in man. The stimulation of the posterior tibial nerve elicited two excitatory phases (short and long latency excitations) at 40 ms and 78 ms latencies, respectively, separated by a phase of reduced activity. With peroneal and sural nerve stimulation such triphasic responses were less consistent; only a monophasic inhibitory response occurred in some recordings. These results indicate that well-identifiable responses with distinct latencies can be obtained in human leg muscle with cutaneous and mixed nerve stimulation distal to the muscle.This work was supported by the Council of Physical Education and Sport (Ministry of Education), Finland.     

Role of metallothioneins in peripheral nerve function and regeneration

The physiological role of the metallothionein (MT) family of proteins during peripheral nerve injury and regeneration was examined in Mt1+ 2 and Mt3 knockout (KO) mice. To this end, the right sciatic nerve was crushed, and the regeneration distance was evaluated by the pinch test 2-7 days postlesion (dpl) and electrophysiologically at 14 dpl. The quality of the regeneration was assessed by light microscopy and immunohistochemical methods. The results show that the regeneration distance was greater in the Mt3 KO than in the Mt1+ 2 KO mice, whereas control mice showed intermediate values. Moreover, the number of regenerating axons in the distal tibial nerve was significantly higher in Mt3KO mice than in the other two strains at 14 dpl. Immunoreactive profiles to protein gene product 9.5 were present in the epidermis and the sweat glands of the plantar skin of the hindpaw of the Mt3 KO group. The improved regeneration observed with the Mt3 KO mice was confirmed by compound nerve action potentials that were recorded from digital nerves at 14 dpl only in this group. We conclude that Mt3 normally inhibits peripheral nerve regeneration.     

On driving and synchronization of the rate of clonic discharges of the two autonomous hippocampal epileptogenic foci by thalamic stimulation

Zusammenfassung Bei Katzen wurde auf beiden Seiten im Hippocampus je ein epileptischer Fokus (Aluminapaste) geschaffen. In einer zweiten Sitzung wurden Elektroden in jeden Hippocampus und in die intralaminären Thalamuskerne implantiert. Durch Reizung in den letzteren Strukturen konnten die sonst voneinander unabhängigen epileptischen Entladungen der beiden Hippocampi synchronisiert werden.