Responses of lateral reticular neurons to sinusoidal stimulation of labyrinth receptors in decerebrate cat

1980 ◽  
Vol 44 (5) ◽  
pp. 922-936 ◽  
Author(s):  
L. Kubin ◽  
P. C. Magherini ◽  
D. Manzoni ◽  
O. Pompeiano
Keyword(s):  
Firing Rate ◽  
Longitudinal Axis ◽  
Vestibular Nuclei ◽  
Peak Amplitude ◽  
Reticular Nucleus ◽  
Slow Rotation ◽  
Medullary Reticular Formation ◽  
Decerebrate Cat ◽  
Reticular Neurons ◽  
Stimulation Of

1. The electrical activity of 106 individual neurons located in the precerebellar lateral reticular nucleus (NRL) and the surrounding medullary reticular formation (RF) has been recorded in precollicular decerebrate cats during sinusoidal tilt around the longitudinal axis of the whole animal leading to stimulation of labyrinth receptors. 2. Among these lateral reticular neurons tested, 48 of 712 (67.6%) NRL neurons and 11 of 35 (31.4%) RF neurons responded to slow rotation of the animal at the standard frequency of 0.026 Hz and at the peak amplitude of displacement of 5-10 degrees. 3. All the responsive units showed a periodic modulation of firing rate during the sinusoidal stimulus. In particular, 35 of 57 units (i.e., 61.4%) were excited during side-up and depressed during side-down tilt of the whole animal; on the other hand, 14 of 57 units (i.e., 24.6%) showed the opposite behavior. In both instances, the peak of the responses occurred with an average phase lead of about 16 degrees with respect to the extreme side-up or side-down position of the animal. The remaining eight units (i.e., 14%) showed a phase shift of the peak of their response of about 90 degrees with respect to the animal position. 4. The sensitivity of the responses, expressed in percentage change of the average firing rate per degree of displacement, did not change by increasing the peak amplitude of tilt from 5 to 15 degrees at the frequency of 0.026 Hz. This finding indicates that the system was relatively linear with respect to the amplitude of stimulation. The sensitivity of the units, however, slightly increased but the phase angle of the responses did not change by increasing the frequency of tilting from 0.015 to 0.15 Hz at the peak amplitude of 5 or 10 degrees. These findings indicate that the responses depended on stimulation of macular labyrinth receptors. 5. Most of the lateral reticular units affected by tilt received also a bilateral convergent input from the hindlimbs. 6. These observations are related to the results of previous studies in which the responses of macular afferents, vestibular nuclei neurons, and corticocerebellar Purkinje (P) cells to sinusoidal tilt of the whole animal have been investigated. A possible role of lateral reticular neurons in the labyrinth control of posture in decerebrate cat is also discussed.

Responses of medullary reticulospinal neurons to sinusoidal stimulation of labyrinth receptors in decerebrate cat

1983 ◽  
Vol 50 (5) ◽  
pp. 1059-1079 ◽  
Author(s):  
D. Manzoni ◽  
O. Pompeiano ◽  
G. Stampacchia ◽  
U. C. Srivastava
Keyword(s):  
Phase Angle ◽  
Intermediate Phase ◽  
Longitudinal Axis ◽  
Peak Amplitude ◽  
Slow Rotation ◽  
Medullary Reticular Formation ◽  
Peak Displacement ◽  
Decerebrate Cat ◽  
Reticulospinal Neurons ◽  
Stimulation Of

The electrical activity of 168 individual neurons located in the medullary reticular formation, namely, in the medial aspects of the nucleus reticularis gigantocellularis, magnocellularis, and ventralis, has been recorded in precollicular decerebrate cats during sinusoidal tilt about the longitudinal axis of the whole animal, leading to stimulation of labyrinth receptors. In particular, 93 neurons were activated antidromically by stimulation of the spinal cord at T12 and L1 (1RS neurons); the remaining 75 neurons were not activated antidromically (RF neurons). Among these medial reticular neurons tested, 64 of 93 (i.e., 69%) 1RS neurons and 49 of 75 (i.e., 65%) RF neurons responded to slow rotation of the animal at the standard frequency of 0.026 Hz and at the peak amplitude of displacement of 10 degrees. A periodic modulation of firing rate of the units was observed during the sinusoidal stimulus. In particular, 71 of 113 units (i.e., 63%) were excited during side-up and depressed during side-down tilt, whereas 24 of 113 units (i.e., 21%) showed the opposite behavior. In both instances, the peak of the responses occurred with an average phase lead of about +25 degrees with respect to the extreme side-up or side-down position of the animal. The remaining 18 units (i.e., 16%) showed a prominent phase shift of the peak of their response with respect to animal position. Within the explored region of the medulla, the proportion of units excited during side-up tilt was higher at caudal levels, whereas that of the units excited during side-down tilt was higher at rostral levels. Units displaying intermediate phase angle of the responses predominated at intermediate levels of the medulla. Responses to animal tilt were detectable at 1 degree of peak displacement. The gain (impulses x s-1 x deg-1) of the responses of reticulospinal neurons did not change by increasing the peak amplitude of tilt from 5 to 20 degrees at the fixed frequency of 0.026 Hz. This finding indicates that the system was relatively linear with respect to the amplitude of displacement. By varying the frequency of stimulation from 0.008 to 0.32 Hz at the fixed amplitude of 10 degrees, two populations of reticulospinal neurons were observed. In the first, the gain and the phase angle of response remained relatively unmodified against changes in frequencies: these positional responses were attributed to stimulation of macular receptors.(ABSTRACT TRUNCATED AT 400 WORDS)

Horizontal Rotation Responses of Medullary Reticular Neurons in the Decerebrate Cat1

1995 ◽  
Vol 5 (3) ◽  
pp. 223-228
Author(s):  
Robert H. Schor ◽  
Bill J. Yates
Keyword(s):  
Spinal Cord ◽  
Reticular Formation ◽  
Semicircular Canal ◽  
Semicircular Canals ◽  
Response Dynamics ◽  
Medullary Reticular Formation ◽  
Decerebrate Cat ◽  
Reticular Neurons ◽  
Semicircular Canal Afferents

This study examines the response of neurons in the medullary reticular formation of the decerebrate cat to sinusoidal yaw rotations in the plane of the horizontal semicircular canals. Responsive neurons that could be antidromically activated from the spinal cord appeared to be less sensitive to the rotary stimulus than the rest of the population of responsive neurons. Most neurons had response dynamics similar to those of semicircular canal afferents.

Discharge properties of pontine reticulospinal neurons during sleep-waking cycle

1978 ◽  
Vol 41 (3) ◽  
pp. 821-834 ◽  
Author(s):  
P. W. Wyzinski ◽  
R. W. McCarley ◽  
J. A. Hobson
Keyword(s):  
Spinal Cord ◽  
Firing Rate ◽  
Neuronal Population ◽  
Spinal Reflex ◽  
Reticular Nucleus ◽  
Medullary Reticular Formation ◽  
Reticulospinal Neurons ◽  
Reflex Pathways ◽  
Naturally Occurring ◽  
Generator Function

1. Reticulospinal neurons were identified by antidromic invasion from spinal cord electrodes chronically implanted at C4 in cats. 2. Most of the neuronal population studied lay within the medial portion of the giant cell field from the anterior pontine and to the anterior medullary reticular formation (FTG). A few cells were found in the tegmental reticular nucleus (TRC) which has not previously been known to project to the spinal cord. 3. Extracellular action potentials from the neuronal somata of the identified neurons were recorded continuously throughout naturally occurring sleep-waking cycles. 4. The identified reticulospinal neurons shared three properties, suggesting a generator function in desynchronized sleep (D) (with previously recorded but unidentified FTG neurons): selectivity (or concentration of discharge in D); tonic latency (or firing rate increases beginning several minutes prior to D); and phasic latency (or firing rate increases occurring prior to eye movements within D). 5. The location, discharge properties, and spinal projections of FTG neurons are, thus, all consistent with the hypothesis that they may directly mediate some of the descending excitatory and inhibitory influences on spinal reflex pathways in desynchronized sleep.

Dynamics of neck-to-forelimb reflexes in the decerebrate cat

1983 ◽  
Vol 50 (3) ◽  
pp. 688-695 ◽  
Author(s):  
K. Ezure ◽  
V. J. Wilson
Keyword(s):  
Head Rotation ◽  
Longitudinal Axis ◽  
Triceps Brachii ◽  
Vestibular Reflexes ◽  
Sinusoidal Analysis ◽  
Low Frequencies ◽  
Decerebrate Cat ◽  
Splenius Capitis ◽  
Response Phase ◽  
Stimulation Of

We have studied the neck-to-forelimb reflex evoked by head rotation around the longitudinal axis (roll) in the long and medial heads of triceps brachii of decerebrate, acutely labyrinthectomized cats. Reflexes were measured by recording mass electromyogram (EMG). As expected from the work of others, they were reciprocal in the two limbs, with excitation in the limb toward which the chin rotates. The reflex was sufficiently linear for a sinusoidal analysis. Although there was sometimes adaptation at stimulus frequencies of 0.1 Hz and below, response phase at these frequencies was usually in phase with position, and gain was flat. At higher frequencies there was some sensitivity to the velocity of the stimulus: gain increased with a slope of 10 dB/decade and phase advanced in some cats but not in others. Gain at low frequencies of head rotation, expressed as percent modulation of EMG, was typically 1%/deg or less. Reflexes evoked by head rotation in triceps and in the neck extensor splenius capitis have different dynamics. It remains to be determined whether this difference is due to activation of different receptors. We compared the dynamics of roll reflexes evoked by stimulation of neck receptors with those of vestibular reflexes evoked by tilt of the whole animal (23). Taking into account dynamics and gain, the two reflexes should cancel at low frequencies, as predicted by others. Above 0.2 Hz, cancellation becomes less effective.

Vertical vestibular input to and projections from the caudal parts of the vestibular nuclei of the decerebrate cat

1995 ◽  
Vol 74 (1) ◽  
pp. 428-436 ◽  
Author(s):  
K. Endo ◽  
D. B. Thomson ◽  
V. J. Wilson ◽  
T. Yamaguchi ◽  
B. J. Yates
Keyword(s):  
Spinal Cord ◽  
Vestibular Nuclei ◽  
Otolith Organs ◽  
Vestibular Input ◽  
Decerebrate Cat ◽  
Central Processing ◽  
Advanced Phase ◽  
Vestibulospinal Neurons ◽  
Response Vector ◽  
Stimulation Of

1. To investigate the type of vestibular signals that neurons in the caudal parts of the vestibular nuclei transmit to the cerebellum and spinal cord, we studied their responses to natural vestibular stimulation in vertical planes in decerebrate cats with the caudal cerebellum removed. Most neurons were in the caudal half of the descending vestibular nucleus, the remainder at corresponding levels of the medial nucleus or the medial-descending border. 2. Dynamics of the responses of spontaneously firing neurons were studied with sinusoidal tilts delivered at 0.05-1 Hz near the plane of body rotation that produced maximal modulation of the neuron's activity (response vector orientation). For most neurons the predominant vestibular input could be identified as coming from otolith organs (46%) or vertical semicircular canals (37%). Some neurons had otolith+canal convergence (9%) and others either had such converging input or some other form of central processing (8%). 3. Gain and phase of the responses of otolith neurons were comparable with values obtained in earlier studies on Deiters' nucleus and the rostral descending nucleus. Many canal neurons had a steeper gain slope and more advanced phase than observed previously for more rostral neurons. This may be due to more irregular afferent input to many neurons or to the absence of the vestibulocerebellum. 4. Response vector orientations of canal neurons were closely bunched near the planes of the ipsilateral vertical canals. The small number of contralaterally projecting vectors showed evidence of convergence between the two contralateral vertical canals. As is the case elsewhere in the vestibular nuclei, there was no evidence of convergence from bilateral vertical canals. Response vector orientations of otolith neurons were restricted to the roll quadrants; the majority pointed ipsilaterally. 5. Antidromic stimulation with an electrode in the restiform body or with several electrodes in the dorsal half of the white matter of the upper cervical cord was used to identify neurons projecting to the cerebellum and spinal cord, respectively. A substantial number of spontaneously firing neurons projected to the cerebellum, but there were few spontaneously active vestibulospinal neurons. The properties of the vestibular input to cerebellar-projecting neurons were the same as those of the population as a whole, but the effect of tilt on vestibulospinal neurons appeared weak or absent. 6. Many neurons were inhibited by stimulation of the restiform body. We suggest that this is mainly due to stimulation of the axons of vestibulocerebellar Purkinje cells. 7. Our results demonstrate a robust vertical vestibular input to the caudal parts of the vestibular nuclei.(ABSTRACT TRUNCATED AT 400 WORDS)

Properties of projections from vestibular nuclei to medial reticular formation in the cat

1975 ◽  
Vol 38 (6) ◽  
pp. 1421-1435 ◽  
Author(s):  
B. W. Peterson ◽  
C. Abzug
Keyword(s):  
Reticular Formation ◽  
Central Region ◽  
Vestibular Nucleus ◽  
Extracellular Recording ◽  
Vestibular Nuclei ◽  
Medullary Reticular Formation ◽  
Pentobarbital Anesthesia ◽  
Antidromic Responses ◽  
Series Of Experiments ◽  
Stimulation Of

In one series of experiments, vestibular neurons that could be activated antidromically by stimulation of the contralateral medial reticular formation were studied with extracellular recording in cats under pentobarbital anesthesia. These neurons were found in all of the four main vestibular nuclei, but were less prevalent in dorsal Deiters' nucleus and in the central region of the superior vestibular nucleus than elsewhere. Regions of the pontine and medullary reticular formation from which neurons in different vestibular nuclei were activated corresponded to the pattern of vestibuloreticular projections described by neuroanatomists. 2. Latencies of antidromic responses to stimulation of the contralateral reticular formation ranged from 0.6 to over 3 ms, indicating a relatively slow transfer of activity from vestibular nuclei to reticular formation.

scholarly journals Vestibular nucleus neurons respond to hindlimb movement in the decerebrate cat

2014 ◽  
Vol 111 (12) ◽  
pp. 2423-2432 ◽  
Author(s):  
Milad S. Arshian ◽  
Candace E. Hobson ◽  
Michael F. Catanzaro ◽  
Daniel J. Miller ◽  
Sonya R. Puterbaugh ◽  
...  
Keyword(s):  
Firing Rate ◽  
Vestibular Nucleus ◽  
Vestibular Nuclei ◽  
Limb Movement ◽  
Decerebrate Cat ◽  
Direction Of Movement ◽  
Contralateral Ear ◽  
Hindlimb Movement ◽  
Proprioceptive Afferents ◽  
Decerebrate Cats

The vestibular nuclei integrate information from vestibular and proprioceptive afferents, which presumably facilitates the maintenance of stable balance and posture. However, little is currently known about the processing of sensory signals from the limbs by vestibular nucleus neurons. This study tested the hypothesis that limb movement is encoded by vestibular nucleus neurons and described the changes in activity of these neurons elicited by limb extension and flexion. In decerebrate cats, we recorded the activity of 70 vestibular nucleus neurons whose activity was modulated by limb movements. Most of these neurons (57/70, 81.4%) encoded information about the direction of hindlimb movement, while the remaining neurons (13/70, 18.6%) encoded the presence of hindlimb movement without signaling the direction of movement. The activity of many vestibular nucleus neurons that responded to limb movement was also modulated by rotating the animal's body in vertical planes, suggesting that the neurons integrated hindlimb and labyrinthine inputs. Neurons whose firing rate increased during ipsilateral ear-down roll rotations tended to be excited by hindlimb flexion, whereas neurons whose firing rate increased during contralateral ear-down tilts were excited by hindlimb extension. These observations suggest that there is a purposeful mapping of hindlimb inputs onto vestibular nucleus neurons, such that integration of hindlimb and labyrinthine inputs to the neurons is functionally relevant.

Cardiac input to medullary reticular formation: neuronal responses to CAO

1986 ◽  
Vol 251 (4) ◽  
pp. R670-R679
Author(s):  
R. W. Blair
Keyword(s):  
Reticular Formation ◽  
Coronary Arteries ◽  
Cell Activity ◽  
Cardiac Ischemia ◽  
Neuronal Responses ◽  
Medullary Reticular Formation ◽  
Reticular Neurons ◽  
Extracellular Potentials ◽  
Medullary Neurons ◽  
Stimulation Of

Responses of 46 medullary reticular neurons to coronary arterial occlusions (CAO) of the left anterior descending (LAD) and left circumflex (CX) coronary arteries were determined in chloralose-anesthetized cats paralyzed with pancuronium. Extracellular potentials were recorded from individual neurons, in the medial reticular formation, responsive to electrical stimulation of cardiopulmonary sympathetic afferents. CAO responses were characterized by one of three patterns. Cell activity changed during myocardial ischemia (IS response). Fifteen neurons were excited during ischemia (9 +/- 2.8 to 15 +/- 3.2 spikes/s for CX occlusion and 10 +/- 3.0 to 17 +/- 4.7 spikes/s for LAD occlusion), and two were inhibited (8 +/- 3.0 to 4 +/- 3.0 spikes/s). Cell activity changed at the onset or release of occlusion and rapidly adapted (ON response). Four cells were excited at the onset of LAD occlusion (2 +/- 1.4 to 10 +/- 6.0 spikes/s), 9 cells were excited at onset of CX occlusion (5 +/- 2.5 to 16 +/- 5.6 spikes/s), and 1 cell decreased its rate at onset of CX occlusion. A combination of ON and IS responses occurred in five cells (ON-IS response). Overall, 24 neurons exhibited at least one of these responses, and 22 cells were unaffected by CAO. Thirty neurons were tested for responses to CAO of CX and LAD; neurons most often exhibited different patterns of responses to CAO of each artery. Thirty-one of 34 cells tested exhibited qualitatively, but often not quantitatively, similar responses to cardiac ischemia and to application of bradykinin to epicardium of free wall of left ventricle. Results indicate that medullary neurons often respond differentially to occlusion of different coronary arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Reticulospinal neurons with and without monosynaptic inputs from cerebellar nuclei

1975 ◽  
Vol 38 (3) ◽  
pp. 513-530 ◽  
Author(s):  
J. C. Eccles ◽  
R. A. Nicoll ◽  
W. F. Schwarz ◽  
H. Taborikova ◽  
T. J. Willey
Keyword(s):  
Spinal Cord ◽  
Receptive Fields ◽  
Cerebellar Nuclei ◽  
Reticular Nucleus ◽  
Antidromic Activation ◽  
Reticulospinal Neurons ◽  
Mean Values ◽  
Air Jet ◽  
Reticular Neurons ◽  
Stimulation Of

An account is given of the responses of 557 medial reticular neurons with axons projecting down the spinal cord. All 30 experiments were on decerebrated unanesthetized cats paralyzed by Flaxedil. Recording from single neurons was by extracellular glass microelectrodes. Identification was first by location (confirmed by subsequent histology) in the medial reticular nucleus of medulla or pons, and second by antidromic activation from cord stimulation at C2 and L2 segmental levels. Axonal conduction velocities were calculated from the latency differential between L2 and C2 antidromic responses, and were usually in the range of 90-140 m/s; but about 25% were slower, ranging down to 30 m/s. Stimulation by electrodes in the ipsilateral and contralateral fastigial nuclei differentiated reticulospinal neurons into two classes according to whether they did or did not receive monosynaptic inputs, the respective populations of fully investigated neurons being 270 and 174. The fastigioreticular neurons were distinguished by a higher background frequency with mean values of 28 as against 15/s. There were also significant diffences in both the excitatory and inhibitory responses to afferent volleys from forelimb and hindlimb nerves. Comparison of the respective latency histograms showed that the responses of neurons with a fastigial input had an excess of latencies in the ranges that can be correlated with the latency histograms observed for fastigial responses. Thus, there is evidence for the effectiveness of the fastigial input and so for the pathway with monosynaptic linkage: Purkinje cells of cerebellar vermis yields fastigial neurons yields medial reticular neurons projecting down the spinal cord. Adequate stimulation of cutaneous receptors by pad taps and air-jet stimulation of hairy skin in a disppointingly small action when compared with fastigical responses. Explanations of this deficiency are suggested. Another discrpancy from the fastigial responses is that the medial reticular neurons have much wider receptive fields with little discrimination between ipsilateral and contralateral and between forelimb and hindlimb. Stimulation of the ipsilateral tegmental tract was tested on 183 reticulospinal neurons, 112 being with fastigial inputs. In about half there was a powerful monosynaptic excitation, which would identify such neurons as being on the pathway from mesencephalic and diencephalic centers to the spinal cord. There is a general discussion of transmission across successive synaptic relays, where specificity is sacrificed to integration.

Medial reticular and perihypoglossal neurons projecting to cerebellum

1976 ◽  
Vol 39 (1) ◽  
pp. 102-108 ◽  
Author(s):  
J. C. Eccles ◽  
R. A. Nicoll ◽  
D. W. Schwarz ◽  
H. Taborkova ◽  
T. J. Willey
Keyword(s):  
Cerebellar Nuclei ◽  
Excitatory Input ◽  
Reticular Nucleus ◽  
Cutaneous Mechanoreceptors ◽  
Good Accord ◽  
Similar Range ◽  
Reticular Neurons ◽  
Central Tegmental Tract ◽  
Experimental Findings ◽  
Stimulation Of

Almost 10% of neurons in the medial reticular nucleus or adjacent thereto were invaded antidromically in response to stimulation of the fastigial and interpositus nuclei. The fraction was 77/835 for the bulbar and caudal pontine levels, but 0/167 for rostral pontine levels. The mahority, 49, of the neurons projecting to the cerebellum were superficially located in the region of the perihypoglossal nucleus, but 23 were scattered through the medial reticular nucleus, being 2.5-5.0 mm below the bulbopontine dorsum. Both classes of cerebellopetal neurons had a similar range of antidromic latencies, usually from 0.8 to 2.0 ms, but some were ober 3 ms. Both classes responded to volleys from limb nerves and inputs from cutaneous mechanoreceptors, with ranges of excitatory and inhibitory latencies that were similar to those for other medial reticular neurons. It is conjectured that the axonal projection is primarily to the cerebellar cortex and that the branches to the nuclei are often slender, hence the long antidromic latencies; 31 of 59 neurons tested projected to cerebellar nuclei on both sides, often with a considerable latency differential. Rarely, there were also axonal branches projecting up the central tegmental tract. The experimental findings are in very good accord with the anatomical descriptions of Brodal and associates (4, 5, 8, 19). It is suggested that the paramedian reticular and the perihypoglossal nuclei may provide a background excitatory input to the interpositus nuclei.

Sign in / Sign up

Export Citation Format

Share Document