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PubMed1986

[Cholinergic systems in bronchospasm].

A neuronal cholinergic system is widely distributed in larger airways, particularly around bifurcations. These neurons form efferent pathways from the brainstem ending in the motor end-plate on smooth muscle, and ciliated and mucus-producing cells. Impulses originating in various sensory endings in the airways, from the central nervous system and from many sensory receptors throughout the body, influence the activity of the cholinergic system thereby controlling the patency of the airways and modulating the rate and depth of breathing. A non-neuronal cholinergic system present on mast cells facilitates their degranulation, resulting in the release of chemical mediators. These induce bronchospasm directly but also indirectly by activating the neuronal cholinergic system. Effective bonchodilator drugs are all antagonists of the cholinergic system. The most effective bronchodilators, however, are physiological antagonists of cholinergic and all other known bronchospasm-inducing agents. Such antagonists include beta-adrenergic stimulants and methyl xanthines. Competitive antagonists such as ipratropium which act on muscarinic receptors in the cholinergic motor end-plate are generally less effective. Drugs such as sodium cromoglycate act only prophylactically by reducing the degranulation of mast cells and/or minimizing irritation of airway sensory receptors.

Bronchial Spasm↗
PubMed1978

[The affected medullary segment in paraplegics. Relation to sexual function in men (author's transl)].

The authors made a detailed clinical analysis of 119 stabilized total paraplegics in order to define, as precisely as possible, the limits of the medullary segment which, for each patient, had lost all its functional value. The relationships between the affected segments and the sexual capabilities of these patients show that the segment must: --exclude the sacral spinal cord if reflex erections are to occur; --underly Th. IX at least, or better still Th. XI, for psychogenic turgescence to appear; the efferent pathways seem therefore, to emerge from the cord quite close to the level which receives testicular afferent pathways; --underly or overly Th. XII, L I, and L II for at least the greater part, for emission of sperm to occur; a true abrupt ejaculation probably requires the complementary integrity of the sacral spinal cord.

Adult↗
PubMed1983

Interactions of leucine-enkephalin with alpha-adrenoceptors in the conscious dog.

Leucine-enkephalin (Leu-ENK) administered systemically to the conscious dog increases heart rate and blood pressure, a response prevented by naloxone and hence mediated by opiate receptors. Clonidine attenuates the heart rate increase without affecting the pressor response. Propranolol also reduces the magnitude of the heart rate increase but to a lesser degree than does clonidine. Clonidine appears to inhibit the Leu-ENK-induced heart rate increase by both a centrally mediated increase in vagal tone and a peripheral presynaptic alpha 2-agonist effect. The presence of a pressor response to Leu-ENK after prazosin pretreatment suggests that Leu-ENK may also increase blood pressure independently of the alpha 1-adrenoceptor. Thus, Leu-ENK appears to act via a naloxone-sensitive receptor (perhaps a vagal afferent chemoreceptor), the response involving both sympathetic and parasympathetic mechanisms. The pressor response may also involve a direct effect on peripheral vessels or a non-alpha 1-adrenergic efferent pathway.

Animals↗
PubMed1984

[Projections to the supraoptic and paraventricular nuclei studied in the rat by means of retrograde fluorescent tracers (fast blue, nuclear yellow)].

Afferent projections into rat supraoptic nucleus (SO) and paraventricular nucleus (PVH) were studied with two fluorescent retrograde neuronal tracers: Nuclear Yellow (NY) and Fast Blue (FB). FB labeled cells were found into paraolfactory area (ACB), basolateral amygdaloid nucleus (ABL), lateral hypothalamus (LH), ventromedial nucleus (VMH) and dorsomedial hypothalamic)nucleus (DMH), tegmental nucleus of the pons (TPO). NY labeled cells were found into posterior hypothalamus (PH), dorsal raphe nucleus (DR) and tegmental nucleus of the pons (TPO). Few double-labeled neurons were found into TPO. The finding of double labeled neurons in the TPO is of particular interest. This latter nucleus is classically connected to the cerebellum trough the olivary nucleus and can serve as liaison for transmission of messages, e.g. vestibular, regarding spacial position variations. We can conclude affirming that quite a lot of informations of diverse nature converges on the SO and PVH nuclei that by efferent pathways may regulate hypothalamic neurosecretion, thus modifying the animal's behaviour response to different external stimuli.

Afferent Pathways↗
PubMed1984

[Interneuronal and nerve-tissue connections in human sympathetic ganglia].

Twelve human cervical-thoracic sympathetic ganglia have been studied 3 h after a sudden death. Peculiar osmophilic bodies in the neuronal mitochondria have been revealed electron microscopically. In the preparation successive stages of these bodies formation are seen. Ultrastructure of afferent neural terminals adjoining the sympathetic neuron bodies but divided from them with a gap space is described. The structure of the receptors in the ganglia and that of the sympathetic contacts are compared, the latter are predominantly axodendritic.

Afferent Pathways↗
PubMed1982

[Study of uterine motor responses to vaginal and uterine stimulations in the ewe in estrus].

We recorded in vivo the electromyographic (EMG) activity of the myometrium in 36 conscious ewes, including ovariectomized animals treated with oestrogen and cyclic animals in oestrus. We studied the motor responses of the uterus to distension of the vagina with a speculum and distension of the uterine horn with a balloon. These two types of stimulation provoked an increase in myometrial activity. By comparing the responses before and after hypophysectomy and before and after treatment with an alpha-adrenergic blocking agent, we were able to evaluate the nature of these responses. Vaginal stimulation induced two types of response: 1) a response of long duration, possibly the result of a spinal reflex followed by a reflex release of oxytocin; 2) a response of short duration, probably resulting simply from a spinal reflex whose efferent pathway is composed of sympathetic fibres. Uterine stimulation activated motility in the stimulated horn only. Thus, the observed increase in EMG activity was not a reflex but the response of the uterine muscle to its own distension.

Animals↗
PubMed1981

Suppression of the late component of the carotid occlusion reflex by lesion of the medial forebrain bundle in the rat.

1. The pressor response to a prolonged carotid occlusion in the rat has two components: an early, fast increase in blood pressure, and a late, slow and sustained hypertension. Since the second component can be blocked by a disconnecting lesion near the medial side of the medial forebrain bundle, the hypothesis that this complex structure is involved in the integration of the late pressor reflex was tested. 2. The medial forebrain bundle was partially or completely destroyed, or a disconnecting lesion was made to interrupt some of its medially running afferents and/or efferents. Incomplete lesion caused a transient suppression of the second component in 4 rats, whereas complete lesion in 5 rats or probable interruption of the medial efferent pathways in 3 rats led to suppression of the late component when the one-minute occlusion was performed within one hour after the lesion. 3. The data show that the medial forebrain bundle plays an important role in the integration of the late component of the pressor response to prolonged carotid occlusion.

Animals↗
PubMed1982

[Pathogenesis and clinical features of painful dysfunctions of the locomotor system].

In the pathogenesis of painful dysfunctions of the locomotor apparatus superficial pain, deep pain and compression pain as well as referred pain play a role. The development of this pain is discussed. The differential diagnosis of radicular and pseudoradicular forms of pain of the vertebral column is discussed. The most clinical important rheumatic pain syndromes, myalgia, arthritis and arthrosis as well as the development of pain in gout attacks are described according to the natural history and clinical presentation of the disease. Therapeutic indications are given. The importance of the differential diagnostic evaluation of pain syndrome is stressed, in particular if it seems, that there is no organic background.

Afferent Pathways↗
PubMed1980

The effects of subcortical sensory and motor lesions on conditioned tactile placing in cats with pyramid section.

Cats after unilateral bulbar pyramid section showed permanent loss of tactile placing in the contralateral limbs. However, the cats could be trained to place the forelimb following light touch in a conditioning situation with food as a reward. This conditioned response survived subsequent unilateral red nucleus and cerebellar interposed nucleus lesions. Dorsal quadrant spinal cord lesion at the cervical level produced initial loss of the conditioned tactile placing but is recovered without retraining. Since those lesions interrupted subcortical afferent and efferent pathways essential to reflex tactile placing, these results indicate that reflex and conditioned responses involve different pathways and mechanisms. Training recruits or activates additional pathways for conditioned responses rather than strengthening those subserving the reflex responses.

Animals↗
PubMed1980

[Orthostatic hypotension in tetraplegic patients (author's transl)].

Blood pressure regulation was studied in nine patients with tetraplegia following total cervical section. Ten minutes after placing the patients in an inclined position at 30 degrees there was a marked reduction in blood pressure, an increase in heart rate, and absence of increased peripheral resistance. Valsalva's maneuver was pathological in all cases (lack of overshoot). Circulating catecholamines were measured in five cases and were low in decubitus and did not react to orthostatism. Plasma renin and aldosterone levels were at the upper limits of normal and reacted strongly to orthostatism. Marked hypersensitivity to exogenous angiotensin and noradrenaline was observed in all cases. These modifications result from section of the sympathetic efferent pathways. High plasma renin levels and their increase during orthostatism are not incompatible with these findings and probably result from intervention of renal baroreceptors. Whatever the mechanism involved, this increase in plasma renin activity could play an important role in the control of blood pressure in tetraplegic patients.

Adolescent↗
PubMed1982

Mechanisms of metastasis.

The mechanism by which a malignant tumor cell establishes a metastatic foci is a complex process requiring the successful completion of a series of steps. If any step cannot be completed, the entire process fails. The tumor cell must separate from the primary tumor, gain access to an efferent channel (lymphatic or vascular), survive transport to a distant capillary bed, exit the vessel at the distant site, and obtain a new blood supply within the distant organ, if successful macrometastases are to develop. As the mysteries of this process are being unraveled, numerous heretofore beliefs have been disproven and new beliefs established. The primary malignant tumor is a heterogenous mixture of malignant cells, each subcell type with unique properties. Both lymphatic and vascular channels offer an efferent pathway for tumor cells, whether they be carcinomatous or sarcomatous. The location of the clinical metastasis is not a haphazard process, but rather a combination of selection by the tumor cell and mechanical trapping of the tumor cell fibrin-platelet clot. Finally, investigations are beginning to demonstrate that the immune process is exceedingly complex and its role in defense against malignancy is far from understood. As more is learned, new treatment methods will become available to combat the metastatic process. If metastasis were to be controlled, cancer would be conquered.

Bone Neoplasms↗
PubMed1982

Effects of subcortical electrolytic lesions on the head-eye turning response induced by electrical stimulation of the cat's pulvinar-lateralis posterior nucleus complex.

The relations between three subcortical structures and P-LP, all of them capable of inducing contralateral head-eye turning responses when electrically stimulated, were studied in three groups of cats. In all the experiments stainless steel electrodes were chronically implanted in P-LP and in each group of five cats. Electrodes were also placed respectively in the caudate nucleus, superior colliculus and nucleus centralis lateralis. Series of current intensity threshold values for evoking head-eye turning responses were determined in each group, before and after electrolytic lesion of these three subcortical structures. The total observation period was approximately 30 days. Only the destruction of the superior colliculus produced the loss of the ability of the ipsilateral P-LP to evoke turning response. According to these results it is postulated that the efferent pathway that carries the information for turning response from P-LP runs through the ipsilateral superior colliculus.

Animals↗
PubMed1982

[Parinaud's syndrome and tonic vertical gaze deviation. 3 anatomo-clinical observations].

Two anatomo-clinical cases of downward gaze palsy and one case of upward gaze palsy are reported. A tonic and intermittent downward gaze deviation is described. The supranuclear palsies of the downward gaze were related to paramedian lesions of the rostral mesencephalon; the lesions involved the rostral interstitial nucleus of the medial longitudinal fasciculus, the nucleus interstitial of Cajal, and/or their afferent and/or efferent pathways. The supranuclear palsy of the upward gaze was related to lesions of the posterior commissure. Tonic and intermittent downward deviation of gaze and ocular bobbing have opposed features. The former could be related to disinhibited reticular mesencephalic neurones activated by vestibular inputs. Tonic upward deviation of gaze is also related to a vestibulo-ocular reflex. In this case, partial or total damage of the nucleus of Cajal, and/or its input and/or its output fibers appears to have a critical role.

Aged↗
PubMed1981

[Role of medullary nuclei and the vagus nerve in hypothalamic regulation of the anticoagulant system].

Electric stimulation of the anterior and rostral parts of the lateral hypothalamus induced activation of the medulla oblongata n. ambiguus and did not change the activity of the vagus n. gigantocellularis and n. dorsalis. Thrombin administration induced maximal activity in the nn. vagi within 3--5 min and the maximal hypocoagulation during the same time in the blood. A scheme of efferent pathways for the hypothalamic regulation of the anticoagulating system, is suggested.

Animals↗
PubMed1981

[Neurogenic pulmonary edema following severe head injury--case report (author's transl)].

A case of severe head injury associated with fulminant pulmonary edema considered as neurogenic which developed within short time after the injury was presented. A five-year-old boy who had no previous history of cardiopulmonary disease was struck on his right frontal region by car accident at 15.30 PM on July 5 of 1979. Immediately after the impact he lost his consciousness and subsequently transferred to a local hospital where bilateral dilated pupil and flaccid paralysis of the limbs were noted. On transmission of the patient to Omuta City Hospital 30 minutes after the injury, massive foamy fluid was discharged from the tracheal tube. On admission, he was comatous, with bilateral dilated and fixed pupils and flaccid paralysis of the limbs. There was no retinal bleeding. He showed ataxic respiration with severe stridor and massive discharge of foamy fluid pinkish in colour from the trachea characteristic in pulmonary edema was significant. Chest x-ray film demonstrated perihilar densities suggesting pulmonary edema. CT scan showed extremely small ventricle on both sides without manifestations of intracranial hematomas or cerebral contusion. With an intensive medical treatments including corticosteroids, alkalizing agents and alpha-blocker were administered under controlled respiration, the discharge of edema fluid was gradually decreased and the findings on blood gases were also improved. However neurological signs were aggravated and he died 8 hours after the injury. Central venous pressure was maintained at the level between 8 to 10 cm. From these clinical findings the pulmonary edema was concluded as neurogenic. Direct or indirect injury to the hypothalamic efferent pathway at the level of lower brain stem seemed to be important as the cause of neurogenic pulmonary edema in this case. The possible pathophysiology of neurogenic pulmonary edema associated with brain stem injury and intracranial hypertension was discussed with other related literature.

Brain Concussion↗
PubMed1980

[Ramsay-Hunt's syndrome: a case report with pathological examination (author's transl)].

A patient developed dyssynergia cerebellaris myoclonica, following an epileptic attack at the age of 19 years, with the progressive onset of involuntary movements and a cerebellar syndrome. He was second of a family of six children in which the same affection was present in the older sister while the four others were not affected. The involuntary movements corresponded to krebs type III intentino myoclonus, to massive myoclonic movements, and Krebs type I fibrillary myoclonia. The E.E.G. changes were typical, particularly the constant reinforcement of epileptic potential by photic stimulation. Completely disabled at 35 years, the patient was hospitalized at age 51 and kept under observation for 18 months. The per os administration of 5-hydroxytryptophane (5-H.T.P.), 150 mg daily, without a decarboxylase inhibitor, resulted in a spectacular reduction of the myoclonic movements and a marked improvement in autonomy. The patient died at 53 years of age from deglutition disorders related to oropharyngeal myoclonus. Pathological examination revealed no abnormalities in the brain, particularly in the dentate nuclei and the superior cerebellar penduncles. The only lesions observed were in the spinal cord: atrophy and demyelinization of Goll's columns and of the posterior lumbar and dorsal roots, and slight atrophy of the lateral funiculi. This case raises the problem of the relationship between myoclonus and lesions of the dentate nucleus, observed in 13 out of 16 cases of anatomically confirmed D.C.M., and lesions of its efferent pathways, present in 8 cases out of 16. The case reported here is the only one with an isolated spinal cord lesion, apart from that of Bradshaw in which no lesion was found but the cord had not been examined. The improvement obtained with the precursor of serotonin, 5-H.T.P. in the Lance and Adams syndrome (in which the intention myoclonus is semiologically very close to that of D.C.M., whatever their respective lesions), suggests that pathogenic studies should be carried out along biochemical lines. Though all authors do not agree, many accept a disturbance in serotoninergic pathways in the genesis of intentional myoclonus. The improvement in clinical signs and symptoms obtained in the present case with low doses of 5-H.T.P. brings additional evidence in favor of this hypothesis.

Cerebellar Ataxia↗
PubMed1981

Involvement of pedal neurons in cardio-renal regulation and their connections with identified visceral cells in Helix pomatia L.

Involvement of the cells of pedal ganglia in the regulation of heart activity and their connections with visceral neurons was studied in the central nervous system of Helix pomatia L. It was found that (1) numerous cells of pedal ganglia receive inputs from the heart. The reaction of the pedal cells to heart afferents was characteristic: initial high frequency increase of firing followed by inhibition, then a secondary tonic increase occurred in activity. Some of the pedal cells were activated after a brief delay; (2) many of the cells of the visceral and right parietal ganglia were activated simultaneously with pedal neurons during tactile stimulation of the heart. In different ganglia the answer to heart afferents can be observed to the same or opposite directions but its duration was identical in every cell; (3) one cell of the left pedal ganglion (LP3) formed monosynaptic connections with several cells of the visceral ganglion. The axons of the visceral cells, connected monosynaptically to the neurons LP3, runs into the intestinal nerve. LP3 caused EPSPs on the visceral cells; (4) the heart excitatory motoneuron V41, simultaneously with a number of pedal cells, receives excitatory inputs from the heart. The heart excitatory motoneuron is involved in the afferent and efferent pathways of heart regulatory network; (5) a motoneuron (V43) was identified to cause relaxation of the heart, giving branches into the intestinal nerve and similarly to other motoneurons activated by heart afferents.

Action Potentials↗
PubMed1995

[Laboratory evaluation of autonomic function].

The sympathetic and parasympathetic systems both contain efferent and afferent neurons. The efferent pathway consists of preganglionic neurons with myelinated axons the cell bodies of which are within the central nervous system and postganglionic neurons with unmyelinated axons the cell bodies of which are peripheral. The preganglionic sympathetic fibers arise in the intermediolateral column of the thoracic and upper lumber cord segments, and reach the sympathetic chain whence postganglionic fibers are distributed to the whole body, where they have particular influence on the control of blood pressure, heart rate, swating and pupillary responses. The parasympathetic outflow is grouped into both brainstem nuclear complex and spinal sacral segments. The activities of the sympathetic and parasympathetic systems are partially reflex in nature, which, however, are controlled by numerous descending influences integrated in the hypothalamus and reticular formation. Orthostatic hypotension is the most dramatic circulatory expression of autonomic failure. As one stands, the pull of gravity pools blood in distensible veins below the heart. Diminished venous return reduces cardiac output and unless autonomic compensatory mechanism-baroreflex function performs, subsequent blood pressure fall occurs. This hemodynamic responses to upright posture can be evaluated by the head-up tilt test. More than a 30-mmHg fall of the systolic blood pressure is thought to be an abnormal response; orthostatic hypotension. The next test to study the orthostatic hypotension is to evaluate the site of the baroreflex arc lesions. Plasma noradrenaline (NA) and vasopressin (AVP) responses to the head-up tilt test are available to detect the site of the lesion.(ABSTRACT TRUNCATED AT 250 WORDS)

Autonomic Nervous System↗