Nonlocomotor and Locomotor Hindlimb Responses Evoked by Electrical Microstimulation of the Lumbar Cord in Spinalized Cats

2006 ◽  
Vol 96 (6) ◽  
pp. 3273-3292 ◽  
Author(s):  
Dorothy Barthélemy ◽  
Hugues Leblond ◽  
Janyne Provencher ◽  
Serge Rossignol
Keyword(s):  
Intravenous Injection ◽  
Evoked Responses ◽  
Dorsal Region ◽  
Preliminary Step ◽  
Electrical Microstimulation ◽  
Intraspinal Microstimulation ◽  
Before And After ◽  
Ventral Zones ◽  
Lumbar Cord ◽  
Flexion And Extension

As a preliminary step to using intraspinal microstimulation (ISMS) for rehabilitation purposes, the distribution of various types of hindlimb responses evoked by ISMS in spinal cats (T13) is described. The responses to ISMS applied through a single electrode was assessed, before and after an intravenous injection of clonidine (noradrenergic agonist), using kinematics and electromyographic recordings in subacute (5–7 days, untrained) or chronic (3–5 wk trained on a treadmill) spinal cats. ISMS was applied in the dorsal, intermediate and ventral areas of segments L3–L7, from midline to 3 mm laterally. Uni- and bilateral non-locomotor responses as well as rhythmical locomotor responses were evoked. In the subacute cats, ipsilateral flexion was elicited in the dorsal region of L3–L7, whereas ipsilateral extension was evoked more ventrally and mainly in the caudal segments. Dorsal stimuli could induce ipsilateral flexion followed by ipsilateral extension. Sites inducing bilateral flexion and bilateral extension were similarly distributed to those evoking ipsilateral flexion and extension in the rostrocaudal axis but were evoked from more medial sites. Ipsilateral flexion with crossed extension was evoked from intermediate and ventral zones of all segments and lateralities. Unilateral ipsilateral locomotion was rarely observed. Contralateral locomotion was more frequent and mainly evoked medially, whereas bilateral locomotion was evoked exclusively from dorsal regions. With some exceptions, those distribution gradients were similar in the four conditions (subacute, chronic, pre- and postclonidine), but the proportion of each response could vary. The distribution of ISMS-evoked responses is discussed as a function of known localization of interneurons and motoneurons.

Excitotoxic acid lesions of the primate subthalamic nucleus result in reduced pallidal neuronal activity during active holding

1992 ◽  
Vol 68 (5) ◽  
pp. 1859-1866 ◽  
Author(s):  
I. Hamada ◽  
M. R. DeLong
Keyword(s):  
Subthalamic Nucleus ◽  
Neuronal Activity ◽  
Elbow Flexion ◽  
Ibotenic Acid ◽  
Excitatory Input ◽  
Behavioral Task ◽  
Discharge Rates ◽  
Before And After ◽  
The Mean ◽  
Flexion And Extension

1. To gain a better understanding of the pathophysiology of hemiballismus in primates, and to test directly the hypothesis that the subthalamopallidal projection is excitatory, we studied the effects of lesions of the subthalamic nucleus (STN) on neuronal activity in the globus pallidus (GP) of monkeys during performance of a motor behavioral task. 2. Animals were trained to position and hold a manipulandum to which torque pulses were applied, producing elbow flexion and extension. The activity of neurons in the external (GPe) and internal (GPi) segments of GP was recorded in two monkeys during task performance before and after STN lesions. The STN was lesioned by the fiber-sparing neurotoxins ibotenic acid and/or kainic acid. 3. After lesioning, the firing rate of neurons in both segments of GP, which was measured during the period of holding before torque application, was significantly decreased in both animals. The mean of discharge rates of GPi neurons decreased (P < 0.001) from 69.8 (n = 169, SD = 21.6) to 47.4 spikes/s (n = 180, SD = 22.6) after lesioning. The mean of discharge rates of GPe neurons decreased from 63.6 spikes/s (n = 218, SD = 25.1) before lesions to 41.0 spikes/s (n = 208, SD = 18.1) after lesioning. 4. These results provide further evidence that STN gives rise to a major excitatory input to both segments of the GP and support the hypothesis that dyskinesias result from decreased GPi output.

Albumin synthesis in humans increases immediately following the administration of endotoxin

2002 ◽  
Vol 103 (5) ◽  
pp. 525-531 ◽  
Author(s):  
Hans BARLE ◽  
Anna JANUSZKIEWICZ ◽  
Lars HÅLLSTRÖM ◽  
Pia ESSÉN ◽  
Margaret A. MCNURLAN ◽  
...  
Keyword(s):  
Intravenous Injection ◽  
Early Phase ◽  
The Other ◽  
Synthesis Rate ◽  
Control Group ◽  
Albumin Synthesis ◽  
Fractional Synthesis Rate ◽  
Before And After ◽  
Fractional Synthesis ◽  
Absolute Synthesis

In order to investigate the immediate (i.e. within 3h) response of albumin synthesis to the administration of endotoxin, as a model of a moderate and well controlled catabolic insult, two measurements employing L-[2H5]phenylalanine were performed in 16 volunteers. One group (n = 8) received an intravenous injection of endotoxin (4ng/kg; lot EC-6) immediately after the first measurement of albumin synthesis, whereas the other group received saline. A second measurement was initiated 1h later. In the endotoxin group, the fractional synthesis rate of albumin was 6.9±0.6%/day (mean±S.D.) in the first measurement. In the second measurement, a significant increase was observed (9.6±1.2%/day; P<0.001). The corresponding values in the control group were were 6.6±0.6%/day and 7.0±0.6%/day respectively (not significant compared with first measurement and P<0.001 compared with the second measurement in the endotoxin group). The absolute synthesis rates of albumin were 148±35 and 201±49mg·kg-1·day-1 before and after endotoxin (P<0.01). In the control group, the corresponding values were 131±21 and 132±20mg·kg-1·day-1 (not significant compared with the first measurement and P<0.01 compared with the second measurement in the endotoxin group). In conclusion, these results indicate that albumin synthesis increases in the very early phase after a catabolic insult, as represented by the administration of endotoxin.

Discharge Patterns of Coxal Levator and Depressor Motoneurones of the Cockroach, Periplaneta Americana

1970 ◽  
Vol 52 (1) ◽  
pp. 139-165
Author(s):  
K. G. PEARSON ◽  
J. F. ILES
Keyword(s):  
Peripheral Nerves ◽  
Sensory Input ◽  
Periplaneta Americana ◽  
Motor Axon ◽  
Extracellular Recordings ◽  
Before And After ◽  
Collateral Pathways ◽  
Discharge Patterns ◽  
Flexion And Extension ◽  
Leg Movements

1. Observation of movements of the metathoracic legs of the cockroach before and after section of peripheral nerves allowed identification of muscles involved in flexion and extension of the femur. 2. Extracellular recordings from the nerves to these coxal muscles show that during rhythmic leg movements bursts of activity in a number of levator motor axons were strongly reciprocal and generally non-overlapping with those of a slow depressor motor axon. 3. These reciprocal patterns persisted after removal of all sensory input from the legs. 4. The durations of levator bursts were relatively constant compared to those of the depressor, corresponding to the behavioural observations on leg protraction time. The pattern was asymmetric: levator bursts could be generated without depressor activity, but never the reverse. 5. No evidence was found for inhibitory collateral pathways between antagonist motoneurones. 6. It is proposed that levator motoneurones are driven by a group of bursting interneurones which simultaneously inhibit the ongoing depressor activity.

Pelvic visceral input into the nucleus gracilis is largely mediated by the postsynaptic dorsal column pathway

1996 ◽  
Vol 76 (4) ◽  
pp. 2675-2690 ◽  
Author(s):  
E. D. Al-Chaer ◽  
N. B. Lawand ◽  
K. N. Westlund ◽  
W. D. Willis
Keyword(s):  
Intravenous Injection ◽  
Visceral Pain ◽  
Background Activity ◽  
Dorsal Column ◽  
Mustard Oil ◽  
Medial Lemniscus ◽  
Afferent Pathways ◽  
Nucleus Gracilis ◽  
Before And After ◽  
Postsynaptic Dorsal Column

1. The purpose of this study was to investigate a proposed role for the postsynaptic dorsal column (PSDC) pathway in mediating visceral nociceptive input into the dorsal column (DC) nuclei. 2. In one group of animals, the hypogastric nerves were sectioned, thereby restricting colorectal input into the cord to pelvic afferent pathways known to coverage on lower lumbar and sacral segments. Extracellular recording were made from 41 nucleus gracilis (NG) cells that responded to colorectal distension (CRD). Results reported are from 15 NG cells that were tested before and after the administration of morphine into the sacral cord by microdialysis. 3. The responses of 11 NG cells to CRD were dramatically reduced by morphine infused into the sacral cord through a microdialysis fiber. This reduction was reversed by an intravenous injection of naloxone. Microdialysis administration of 6-cyano-7-nitro-quinoxaline-2,3-dione (CNQX) or a lesion of the DC also abolished the responses of the NG cells to CRD. 4. Four NG cells that responded to CRD showed an increase in their background activity approximately 25 min after an injection of mustard oil (MO). This increase in activity was counteracted by morphine or by a lesion of the DC. 5. In a second group of animals, recordings were made from 28 PSDC cells in the L0-S1 segments of the cord. These units were antidromically activated by stimulation of the upper cervical fasciculus gracilis. The projections of five PSDC neurons into the NG were traced with the use of antidromic mapping. Results are reported for the responses of 12 PSDC cells to CRD and to cutaneous stimuli before and after morphine administration into the sacral cord by microdialysis. 6. Morphine given spinally reduced the responses of 12 PSDC cells to CRD. This reduction was reversed by an intravenous injection of naloxone. CNQX administered spinally also abolished the responses to CRD of the PSDC cells tested. 7. Four other PSDC cells were studied before and after an injection of MO into the colon. Their background activity started to increase within 25 min after the injection. Morphine suppressed this increase in background activity and this effect of morphine was reversed by naloxone. 8. The responses of NG cells to cutaneous stimuli were not significantly affected by morphine in the dose used. On the other hand, morphine significantly reduced the responses of PSDC cells to noxious cutaneous stimuli although this effect was not as dramatic as that on responses to visceral stimuli. 9. From the results of the studies described in this and the companion paper, we conclude that there is an important pelvic visceral nociceptive pathway involving PSDC neurons that synapse in the NG. The NG in turn activates neurons in the ventral posterolateral (VPL) nucleus of the thalamus. We presume that activation of VPL neurons by noxious visceral stimulation contributes to visceral pain sensation and thus that pelvic visceral pain depends largely on activity in the DC-medial lemniscus system.

ACUTE ESERINE POISONING IN THE MONKEY

1954 ◽  
Vol 32 (4) ◽  
pp. 446-451
Author(s):  
C. A. de Candole
Keyword(s):  
Intravenous Injection ◽  
Pulmonary Ventilation ◽  
Minute Volume ◽  
Before And After ◽  
Sublethal Doses ◽  
Respiratory Mechanism

The changes in pulmonary ventilation which follow the intravenous injection of lethal and sublethal doses of eserine in the urethanized monkey have been studied. A reduction in minute volume is the outstanding change; but periods of overventilation may occur both before and after the phase of underventilation.When death takes place within ten minutes respiration fails before the heart, whereas when death is delayed, both fail together.Different elements of the respiratory mechanism differ in their susceptibility to eserine. Thus diaphragmatic and intercostal function are rarely lost together, and gasping may continue for long periods after eupnoeic breathing has failed.

scholarly journals Role of nitric oxide in systemic vasopressin-induced hypothermia

1998 ◽  
Vol 275 (4) ◽  
pp. R937-R941 ◽  
Author(s):  
Alexandre A. Steiner ◽  
Evelin C. Carnio ◽  
José Antunes-Rodrigues ◽  
Luiz G. S. Branco
Keyword(s):  
Nitric Oxide ◽  
Intravenous Injection ◽  
Induced Hypothermia ◽  
Basal Body Temperature ◽  
Systemic Injection ◽  
The Third ◽  
Before And After ◽  
Injection Control ◽  
Synthase Inhibitor

It has been reported that arginine vasopressin (AVP) plays a thermoregulatory action, but very little is known about the mechanisms involved. In the present study, we tested the hypothesis that nitric oxide (NO) plays a role in systemic AVP-induced hypothermia. Rectal temperature was measured before and after AVP, AVP blocker, or N G-nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor) injection. Control animals received saline injections of the same volume. The basal body temperature (Tb) measured in control animals was 36.53 ± 0.08°C. We observed a significant ( P < 0.05) reduction in Tb to 35.44 ± 0.19°C after intravenous injection of AVP (2 μg/kg) and to 35.74 ± 0.10°C after intravenous injection ofl-NAME (30 mg/kg). The systemic injection of the AVP blocker [β-mercapto-β,β-cyclopentamethylenepropionyl1, O-Et-Tyr2,Val4,Arg8]vasopressin (10 μg/kg) caused a significant increase in Tb to 37.33 ± 0.23°C, indicating that AVP plays a tonic role by reducing Tb. When the treatments with AVP and l-NAME were combined, systemically injected l-NAME blunted AVP-induced hypothermia. To assess the role of central thermoregulatory mechanisms, a smaller dose ofl-NAME (1 mg/kg) was injected into the third cerebral ventricle. Intracerebroventricular injection ofl-NAME caused an increase in Tb, but when intracerebroventricular l-NAME was combined with systemic AVP injection (2 μg/kg), no change in Tb was observed. The data indicate that central NO plays a major role mediating systemic AVP-induced hypothermia.

UNCONJUGATED OESTETROL IN PLASMA IN RESPONSE TO AN INTRAVENOUS LOAD OF DEHYDROEPIANDROSTERONE SULPHATE (DHAS) IN UNCOMPLICATED AND COMPLICATED HUMAN PREGNANCY

1978 ◽  
Vol 89 (4) ◽  
pp. 753-762 ◽  
Author(s):  
Ove Axelsson
Keyword(s):  
Pregnant Women ◽  
Intravenous Injection ◽  
Growth Retardation ◽  
Intrauterine Growth Retardation ◽  
High Specificity ◽  
Intrauterine Growth ◽  
Before And After ◽  
Patients With Diabetes ◽  
The Individual ◽  
Plasma Oestradiol

ABSTRACT A non-chromatographic radioimmunoassay for estimation of unconjugated oestetrol in plasma from pregnant women is described. The antiserum has a high specificity to oestetrol. The technical procedure is simple and rapid. Only small amounts of plasma (0.2–0.4 ml) are needed for the analysis. The method has been applied to the measurement of oestetrol in plasma from pregnant women before and after an intravenous injection of 50 mg DHAS. In women with uncomplicated pregnancies a rise of plasma oestetrol was found 60 min after the injection. From 120 to 360 min there was a plateau level, at 600 min a decrease from this level was observed. No changes in the oestetrol response were found with advancing gestational age from the 33rd to the 40th week of pregnancy. A great spread in the individual responses were recorded. Patients with pre-eclampsia and intrauterine growth retardation had a tendency to a lower increase and patients with diabetes a tendency to a higher increase of plasma oestetrol after the DHAS administration. From the data obtained it is concluded that the increase of plasma oestetrol after an intravenous injection of DHAS in most cases is secondary to the increase of plasma oestradiol. The results suggest that measurement of unconjugated oestetrol in plasma after an intravenous load of DHAS is no safe way to assess foetal wellbeing. In women with intrauterine growth retardation (IUGR) the simultaneous measurement of plasma oestradiol and oestetrol after an injection of DHAS indicates a possibility to distinguish placental from foetal causes of this syndrome.

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