Central Control of an Insect Segmental Reflex: I. Inhibition by Different Parts of the Central Nervous System

1964 ◽  
Vol 41 (3) ◽  
pp. 559-572
Author(s):  
C. H. FRASER ROWELL
Keyword(s):  
Central Nervous System ◽  
Inhibitory Influence ◽  
Central Control ◽  
Level Of Activity ◽  
Prothoracic Ganglion ◽  
The Central Nervous System ◽  
Left And Right ◽  
Leg Movement ◽  
Two Sides ◽  
Different Parts

1. A reflex leg movement mediated by the prothoracic ganglion of Schistocerca is completely inhibited under most normal conditions but disinhibited if the ganglion is isolated from the C.N.S. 2. Progressive lesions to the C.N.S. give progressive disinhibition. The main inhibitory areas are the metathoracic, suboesophageal and mesothoracic ganglia. 3. The left and right sides of the thoracic ganglia are to some extent independent in both the transmission and reception of inhibitory signals. There is probably negative feedback between the reflex systems of the two sides of the prothoracic ganglion. 4. The inhibitory influence of a ganglion on the reflex appears to be proportional to its level of activity and to the amount of signal it is transmitting to the prothoracic ganglion. It is not constant, and is probably not mediated by a limited number of specific inhibitory tracts. 5. The general occurrence of similar mechanisms in animal nervous systems is suggested and discussed.

scholarly journals The Movements of the Proboscis in Glycera Dibranchiata Ehlers

1937 ◽  
Vol 14 (3) ◽  
pp. 290-301
Author(s):  
G. P. WELLS
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Wall ◽  
The Body ◽  
Inhibitory Influence ◽  
Spontaneous Movement ◽  
Arenicola Marina ◽  
Glycera Dibranchiata ◽  
The Central Nervous System ◽  
Nervous Conduction

1. The gut of Glycera consists of (a) the buccal tube, (b) the pharynx, containing the jaws with their associated muscles and glands and the principal stomatogastric ganglia, (c) the oesophagus, leading from the pharynx to (d) the intestine, in which digestion occurs. 2. An "isolated extrovert" preparation is described, consisting of the buccal tube, pharynx and oesophagus. The movements of the buccal tube and oesophagus are recorded separately. The preparation has the following properties: (a) The buccal tube shows vigorous, rapid contractions with a somewhat irregular rhythm. These contractions are due to impulses coming forwards from the pharynx, the buccal tube itself having little power of spontaneous movement. (b) The oesophagus shows tone-waves, on which more rapid contractions of small amplitude may be superposed. These contractions and tone-waves are due to impulses originating in the wall of the oesophagus itself. (c) In a few preparations only, synchronous movements of buccal tube and oesophagus were seen. The site of origin of this synchronous activity was not determined. 3. An "extrovert-body wall" preparation is described, in which the movements of the body wall and buccal tube are separately recorded while the normal nervous conduction paths between them remain intact. The preparation has the following properties: (a) In most cases the body wall shows slight movements only, and the buccal tube moves little or not at all. If, however, the buccal tube be cut across close to the mouth, it begins an irregular rhythm of vigorous contractions, due to impulses originating in the pharynx, which usually continues without diminution for hours. The quiescence of the buccal tube before this cut is made indicates that the central nervous system normally exerts an inhibitory influence on the pharynx. (b) In a few preparations, correlated outbursts of contraction in the body wall and buccal tube were seen. These outbursts, which possibly correspond to extrusion movements of the intact worm, are due to impulses originating in the central nervous system. 4. The results are compared with those previously obtained on Arenicola marina, and reported in an earlier paper.

Aspects of the Organization of Central Nervous Pathways in Aplysia Depilans

1962 ◽  
Vol 39 (1) ◽  
pp. 45-69
Author(s):  
G. M. HUGHES ◽  
L. TAUC
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Ganglion Cells ◽  
Rhythmic Activity ◽  
Large Size ◽  
The Central Nervous System ◽  
The Individual ◽  
Two Sides ◽  
Pleural Ganglion

1. The organization of the central nervous system of Aplysia depilans has been investigated in whole animal and isolated ganglion preparations using mechanical and electrical stimulation. 2. Intracellular micro-electrodes have been used to record activity in nerve cells of the abdominal ganglia in situ. Some cells are spontaneously active and quite unaffected by mechanical stimulation, whereas others show varying degrees of responsiveness. Those which are unaffected may exhibit regular rhythmic activity or intermittent bursts which are intrinsic to the cells themselves but in other cases are due to synaptic input from other central neurones. 3. In isolated central nervous system preparations a special study of the pleural ganglion has revealed many types of cell with electrical activity similar to that shown in isolated abdominal ganglion preparations. A notable feature of the pleural ganglion cells was the large size of the excitatory post-synaptic potentials recorded in response to stimulation of pre-synaptic fibres. 4. Different types of branching of cells of the pleural ganglia were investigated. By observing the somatic potential it was possible to decide in which nerve a particular cell sent collateral branches and which nerves contained fibres affecting the cell synaptically. By this means it was clear that a large number of pathways connect the cerebral and pleural ganglia on each side. 5. A large number of direct pathways were found of nerve fibres passing through ganglia without any synapse. 6. Synaptic pathways varied in the number and intrinsic properties of the individual synapses along their route. Synapses between fibres in the nerves innervating the foot and parapodial lobes of the two sides were not as common as has been described for Ariolimax. 7. In general the results have shown a great variety in the extent to which afferent stimulation may affect the whole or part of the central nervous system. They have also revealed the great multiplicity in the pathways whereby this is achieved.

Vestibular effects of intravenous lidocaine used in the treatment of tinnitus

1986 ◽  
Vol 100 (11) ◽  
pp. 1249-1253 ◽  
Author(s):  
Saumil N. Merchant ◽  
Milind V. Kirtane
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Auditory System ◽  
Treatment Modalities ◽  
Positional Nystagmus ◽  
Intravenous Lidocaine ◽  
The Central Nervous System ◽  
The Difference ◽  
Ocular System ◽  
Two Sides

AbstractIntravenous lidocaine is known to have an effect on the auditory system in that it is useful for suppressing tinnitus, albeit temporarily. We have used intravenously administered lidocaine as one of the treatment modalities for refractory, disturbing, tinnitus. Its effects on the vestibulo-ocular system were determined by elec-tronystagmography performed before and immediately after injecting lidocaine: smooth pendular stimulus tracking was unaffected; spontaneous and positional nystagmus tended to be suppressed; directional preponderance was reduced or reversed; and the difference between the nystagmus responses in the two directions during the pendular rotation chair test was also reduced or reversed. These changes in the caloric and rotation tests were statistically significant. Lidocaine also appeared to have altered the balance between the two sides in the vestibulo-spinal system as indicated by the results of the stepping test during craniocorpography. The results lend support to the hypothesis that intravenous lidocaine acts at the level of the central nervous system rather than at the periphery.

The Role of Endocannabinoid Signaling in Motor Control

Physiology ◽  
2010 ◽  
Vol 25 (4) ◽  
pp. 230-238 ◽  
Author(s):  
A. El Manira ◽  
A. Kyriakatos
Keyword(s):  
Central Nervous System ◽  
Motor Skills ◽  
Motor System ◽  
Cannabinoid Receptors ◽  
Retrograde Signaling ◽  
Motor Circuits ◽  
The Central Nervous System ◽  
Different Parts

Cannabinoid receptors and endocannabinoid signaling are distributed throughout the rostrocaudal neuraxis. Retrograde signaling via endocannabinoid mediates synaptic plasticity in many regions in the central nervous system. Here, we review the role of endocannabinoid signaling in different parts of the vertebrate motor system from networks responsible for the execution of movement to planning centers in the basal ganglia and cortex. The ubiquity of endocannabinoid-mediated plasticity suggests that it plays an important role in producing motion from defined circuitries and also for reconfiguring networks to learn new motor skills. The long-term plasticity induced by endocannabinoids may provide a long-term buffer that stabilizes the organization of motor circuits and their activity.

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