Variable Responsiveness of a Visual Interneurone in the Free-Moving Locust, and its Relation to Behaviour and Arousal

1971 ◽  
Vol 55 (3) ◽  
pp. 727-747
Author(s):  
C. H. FRASER ROWELL
Keyword(s):  
Electrical Stimulation ◽  
Motor Activity ◽  
Motor System ◽  
Complete Recovery ◽  
Wide Field ◽  
Movement Detector ◽  
Response Level ◽  
Sensory Stimuli ◽  
Site Specific ◽  
Stimulation Of

1. Recorded from a dissected immobilized animal, or from an unrestrained animal which is quiescent, the descending contralateral movement detector (DCMD) neurone shows an exponential decremental response to a repetitive stimulus (habituation), reaching a plateau level characteristic of the stimulus conditions. The process is site-specific on the retina, and movement to a new area of retina gives a complete recovery. In the absence of stimulation responsiveness returns over minutes or hours. 2. Immediate recovery without a rest (dishabituation) can be obtained by a variety of strong sensory stimuli of several different modalities (‘extra-stimuli’) or by non specific electrical stimulation of parts of the CNS. The dishabituating efficacy of all these wanes with repetition. When the habituating stimulus is moved to a new retinal site the previous site is not dishabituated. 3. Dishabituation is not site-specific but affects the whole retina simultaneously. It appears to reverse the original decremental process (‘re-set’) rather than to produce an independent enhancement elsewhere in the pathway, as it does not increase the response from a submaximally stimulated, but unhabituated, retinal site. 4. In unrestrained animals dishabituating extra-stimuli also cause behavioural arousal or other motor activity. When motor activity starts, the DCMD is dishabituated and shows no regular decremental trend thereafter until movement ceases. DCMD background activity is also increased. These effects are not due to the visual stimulus of the moving appendages. 5. The association between motor activity and dishabituation suggests that the latter derives either from motor system collaterals or from mechanoreceptive reafference. Stimulation of the antennal nerve of a totally de-efferented brain cause some dishabituation; this eliminates the lower motor system (below command-fibre level) as the source of dishabituation and suggests it is purely sensory. 6. The activity of a thoracic cord unit (of possibly a wide-field mechanoreceptor interneurone) precedes by 5-20 sec, and closely correlates with, changes in responsiveness of the DCMD. It is either an important input to, or an output from, the dishabituating system. 7. Progressive reduction of sensory input to the brain affects DCMD responsiveness as follows: (i) spontaneous dishabituation is less frequent, (ii) dishabituation is less easily induced and smaller, (iii) rate of habituation is increased, (iv) plateau response level after habituation is lower. 8. Electrical stimulation of the circumoesophageal connective can depress DCMD responsiveness for many minutes. 9. The probable anatomical and physiological bases for modulation of DCMD responsiveness are discussed.

scholarly journals Propofol Suppresses Synaptic Responsiveness of Somatosensory Relay Neurons to Excitatory Input by Potentiating GABAA Receptor Chloride Channels

2005 ◽  
Vol 1 ◽  
pp. 1744-8069-1-2 ◽  
Author(s):  
Shui-Wang Ying ◽  
Peter A Goldstein
Keyword(s):  
Electrical Stimulation ◽  
Chloride Channel ◽  
Temporal Summation ◽  
Brain Slices ◽  
Excitatory Input ◽  
Dependent Manner ◽  
Sensory Stimuli ◽  
Shunting Inhibition ◽  
Stimulation Of ◽  
Relay Neurons

Propofol is a widely used intravenous general anesthetic. Propofol-induced unconsciousness in humans is associated with inhibition of thalamic activity evoked by somatosensory stimuli. However, the cellular mechanisms underlying the effects of propofol in thalamic circuits are largely unknown. We investigated the influence of propofol on synaptic responsiveness of thalamocortical relay neurons in the ventrobasal complex (VB) to excitatory input in mouse brain slices, using both current- and voltage-clamp recording techniques. Excitatory responses including EPSP temporal summation and action potential firing were evoked in VB neurons by electrical stimulation of corticothalamic fibers or pharmacological activation of glutamate receptors. Propofol (0.6 – 3 μM) suppressed temporal summation and spike firing in a concentration-dependent manner. The thalamocortical suppression was accompanied by a marked decrease in both EPSP amplitude and input resistance, indicating that a shunting mechanism was involved. The propofol-mediated thalamocortical suppression could be blocked by a GABAA receptor antagonist or chloride channel blocker, suggesting that postsynaptic GABAA receptors in VB neurons were involved in the shunting inhibition. GABAA receptor-mediated inhibitory postsynaptic currents (IPSCs) were evoked in VB neurons by electrical stimulation of the reticular thalamic nucleus. Propofol markedly increased amplitude, decay time, and charge transfer of GABAA IPSCs. The results demonstrated that shunting inhibition of thalamic somatosensory relay neurons by propofol at clinically relevant concentrations is primarily mediated through the potentiation of the GABAA receptor chloride channel-mediated conductance, and such inhibition may contribute to the impaired thalamic responses to sensory stimuli seen during propofol-induced anesthesia.

scholarly journals The Development of Motor Responses in the Stomach of the Foetal Sheep

1951 ◽  
Vol 28 (1) ◽  
pp. 32-40
Author(s):  
D. L. DUNCAN ◽  
A. T. PHILLIPSON
Keyword(s):  
Electrical Stimulation ◽  
Motor Activity ◽  
Extended Period ◽  
The State ◽  
Motor Responses ◽  
Sustained Activity ◽  
Stimulation Of

The state of motor activity of the stomach was studied in a series of foetal sheep. The non-functional period was found to end between the 50th and 60th days of gestation. Sustained activity was preceded by short periods of myogenic and neuromotor activity, and was not in evidence until the 70th day. Foetal swallowing commenced soon after this, but the pattern of suckling behaviour developed gradually over an extended period. The motor mechanisms mediated by the vagus were studied by section and electrical stimulation of the nerve.

Neurobiological Background for Performing Surgical Intervention in the Inferior Thalamic Peduncle for Treatment of Major Depression Disorders

Neurosurgery ◽  
2005 ◽  
Vol 57 (3) ◽  
pp. 439-448 ◽  
Author(s):  
Francisco Velasco ◽  
Marcos Velasco ◽  
Fiacro Jiménez ◽  
Ana Luisa Velasco ◽  
Rafael Salin-Pascual
Keyword(s):  
Electrical Stimulation ◽  
Major Depression ◽  
Orbitofrontal Cortex ◽  
Frontal Lobes ◽  
Sleep Stages ◽  
Orbital Frontal Cortex ◽  
Sensory Stimuli ◽  
Surgical Interventions ◽  
Depression Disorders ◽  
Stimulation Of

ABSTRACT OBJECTIVE: To present a review of evidence for an inhibitory thalamo-orbitofrontal system related to physiopathology of major depression disorders (MDDs) and to postulate that interfering with hyperactivity of the thalamo-orbitofrontal system by means of chronic high-frequency electrical stimulation of its main fiber connection, the inferior thalamic peduncle (ITP), may result in an improvement in patients with MDD. METHODS: Experimentally, the thalamo-orbitofrontal system has been proposed as part of the nonspecific thalamic system. Under normal conditions, the nonspecific thalamic system induces characteristic electrocortical synchronization in the form of recruiting responses that mimic some sleep stages. It also inhibits input of irrelevant sensory stimuli, thus facilitating the process of selective attention. Permanent disruption of the system, via lesioning or temporary inactivation through cooling of the ITP with cryoprobes, results in a state of hyperkinesia, increased attention, and cortical desynchronization. RESULTS: Surgical lesioning of the medial part of orbitofrontal cortex and white matter overlying area 13, which includes the ITP, may result in significant improvement in MDD. Imaging studies (functional magnetic resonance imaging and positron emission tomography) consistently demonstrate hyperactivity in the orbitofrontal cortex and midline thalamic regions during episodes of MDD. This hyperactivity decreases with efficient control of MDD by medical treatment, indicating that orbitofrontal cortex and midline thalamic overactivity are related to the depressive condition. Conversely, noradrenergic and serotoninergic systems in the frontal lobes have been implicated in the pathophysiology of MDD. Although noradrenergic receptor density in the frontal lobe is consistently increased in depressed patients who commit suicide, 5-hydroxytryptamine reuptake blockers, which are potent antidepressive drugs, decrease hypermetabolism in the orbital frontal cortex in MDD. Therefore, the serotonin hypothesis for depression postulates that norepinephrine and serotonin in the frontal lobes are required to maintain antidepressive responsiveness. Dysregulation of the secretion of both neurotransmitters initiates overactivity of orbitofrontal cortex, resulting in depression. It is possible that surgical interventions in this region, including electrical stimulation of ITP, disrupt adrenergic and serotoninergic dysregulation in patients with MDD. CONCLUSION: Circumscribed lesions or electrical stimulation of the ITP, a discrete target easily identified by electrophysiological studies, may improve MDD. Electrical stimulation may have the advantage of being less invasive and more adjustable to patient needs.

Presynaptic inhibition of transmission from identified interneurons in locust central nervous system

1981 ◽  
Vol 45 (3) ◽  
pp. 501-515 ◽  
Author(s):  
K. G. Pearson ◽  
C. S. Goodman
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Electrical Stimulation ◽  
Action Potentials ◽  
Presynaptic Inhibition ◽  
Auditory Stimuli ◽  
Movement Detector ◽  
Intracellular Recordings ◽  
Contralateral Movement ◽  
Stimulation Of

1. Intracellular recordings near the output terminals of an identified interneuron (the descending contralateral movement detector, DCMD) in the locust revealed the occurrence of depolarizing synaptic potentials. These presynaptic depolarizing potentials were evoked by spikes in both DCMDs, by auditory stimuli, and by electrical stimulation of the pro- to mesothoracic connectives. The occurrence of the depolarizing potentials decreased the amplitude of the action potentials close to the output terminals. 2. The stimuli that produced depolarizing potentials in the presynaptic terminals reduced the amplitude of the monosynaptic excitatory postsynaptic potentials evoked by the DCMDs in identified follower interneurons. We conclude that at least part of this reduction in transmission from the DCMDs results from presynaptic inhibition and that the presynaptic inhibition is related to a reduction in the amplitude of the presynaptic action potentials. 3. We propose that the function of the presynaptic inhibition of the DCMDs is to ensure that the interneurons triggering a jump are never activated by the DCMDs in the absence of proprioceptive signals from the legs indicating the animal's readiness to jump.

Electrical Stimulation of the Motor System

Orthopedics ◽  
1984 ◽  
Vol 7 (7) ◽  
pp. 1111-1111
Author(s):  
Robert D D'Ambrosia
Keyword(s):  
Electrical Stimulation ◽  
Motor System ◽  
Stimulation Of

scholarly journals Understanding Variable Motor Responses to Direct Electrical Stimulation of the Human Motor Cortex During Brain Surgery

2021 ◽  
Vol 8 ◽  
Author(s):  
Daniel M. Aaronson ◽  
Eduardo Martinez Del Campo ◽  
Timothy F. Boerger ◽  
Brian Conway ◽  
Sarah Cornell ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Motor Cortex ◽  
Motor System ◽  
Neurosurgical Procedures ◽  
Direct Electrical Stimulation ◽  
Human Motor Cortex ◽  
Motor Responses ◽  
Human Motor ◽  
The Brain ◽  
Stimulation Of

Direct electrical stimulation of the brain is the gold standard technique used to define functional-anatomical relationships during neurosurgical procedures. Areas that respond to stimulation are considered “critical nodes” of circuits that must remain intact for the subject to maintain the ability to perform certain functions, like moving and speaking. Despite its routine use, the neurophysiology underlying downstream motor responses to electrical stimulation of the brain, such as muscle contraction or movement arrest, is poorly understood. Furthermore, varying and sometimes counterintuitive responses can be seen depending on how and where the stimulation is applied, even within the human primary motor cortex. Therefore, here we review relevant neuroanatomy of the human motor system, provide a brief historical perspective on electrical brain stimulation, explore mechanistic variations in stimulation applications, examine neurophysiological properties of different parts of the motor system, and suggest areas of future research that can promote a better understanding of the interaction between electrical stimulation of the brain and its function.

Influence of Robotic Mechanotherapy in Various Combinations with Non-Invasive Electrostimulation of Muscles and Spinal Cord on the Postural Balance in Children with Severe Forms of Cerebral Palsy

2020 ◽  
Vol 98 (4) ◽  
pp. 26-34
Author(s):  
I.E. Nikityuk ◽  
E.L. Kononova ◽  
G.A. Ikoeva ◽  
I.Yu Solokhina
Keyword(s):  
Spinal Cord ◽  
Cerebral Palsy ◽  
Electrical Stimulation ◽  
Motor Activity ◽  
Main Group ◽  
Vertical Posture ◽  
Locomotor Training ◽  
Transcutaneous Electrical Stimulation ◽  
Group 10 ◽  
Stimulation Of

Introduction. Postural disorders are significant in severe forms of cerebral palsy (CP). The aim of the work was to study the effect of locomotor training in combination with transcutaneous electrical stimulation of the spinal cord and functional electrical stimulation (FES) of the muscles of the lower extremities on the restoration of the function of maintaining a vertical posture in children with III level of limitation of motor activity according to the GMFCS classification. Materials and methods. 20 patients with CP at the age from 8 to 12 years old were examined. Patients of the main group (10 children) received 15 sessions of 45 minutes rehabilitation in the ≪Lokomat≫ robotic simulator in the sequence: 1) ≪Lokomat≫ in combination with FES, 2) ≪Lokomat≫ in combination with transcutaneous electrical stimulation of the spinal cord, 3) ≪Lokomat≫ in combination with FES and transcutaneous electrical stimulation of the spinal cord. The intervals between courses were 6 months. Patients from the control group (10 children) underwent only locomotor training. Results. The dynamics of regaining control of the upright posture in children was evaluated by the method of stabilometry, which revealed the active response of the musculoskeletal system in patients of the main group only in the case of combined robotic mechanotherapy and FES. This was manifested in a significant increase in the amplitude of oscillations A of the pressure center, a clear increase in the variance of the parameters of the LFS parameter, and a decrease in the strength of the correlation between the parameters LFS and A towards normalization. However, with a combination of locomotor training with FES and transcutaneous electrical stimulation of the spinal cord, there were no convincing signs of improving the regulation of the vertical posture. Conclusion. It is suggested that multilevel neurostimulation of patients with CP is necessary, which may be more effective, since it will affect the central components of motor activity.

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