LES NEURONES DE LA FORMATION RÉTICULAIRE PONTO-BULBAIRE ET LA STIMULATION TRIGÉMINALE

1962 ◽  
Vol 40 (1) ◽  
pp. 261-271
Author(s):  
Guy Lamarche ◽  
J.-M. Langlois
Keyword(s):  
Reticular Formation ◽  
Trigeminal Nerve ◽  
Neuronal Response ◽  
Receptive Fields ◽  
Central Zone ◽  
Painful Stimulus ◽  
Inhibitory Zone ◽  
Sensory Afferents ◽  
Reticular Neurons

A microphysiological study of 209 neurons of the bulbopontine reticular formation was carried out in 80 "encéphales isolés" cats. After physiological stimulations of the trigeminal nerve the following conclusions were arrived at: (1) A functional arrangement exists in the lower recticular formation. Clear differences were found between the medulla and pons. (2) The pontine reticular neurons receive mostly tactile impulses from very large receptive fields. (3) The bulbar neurons receive all modalities of the trigeminal nerve from usually limited and bilateral fields (except proprioception). Pain projects mainly in this part of the reticular core. A central zone of the medulla has all physiological types of cells and is coincidental with Magoun and Rhine's inhibitory zone. (4) There was no neuronal response typical of any sensation. (5) An increase in frequency of a response was obtained in various ways: by changing the origin of the stimulus, by-increasing the intensity of the stimulus or the area of stimulation, or by applying a painful stimulus when the cell also responded to touch. (6) It is suggested that the sensory afferents lose their specificity when they reach the reticular formation but that via this formation they serve to increase awareness and perception of sensation at higher level.

LES NEURONES DE LA FORMATION RÉTICULAIRE PONTO-BULBAIRE ET LA STIMULATION TRIGÉMINALE

1962 ◽  
Vol 40 (2) ◽  
pp. 261-271 ◽  
Author(s):  
Guy Lamarche ◽  
J.-M. Langlois
Keyword(s):  
Reticular Formation ◽  
Trigeminal Nerve ◽  
Neuronal Response ◽  
Receptive Fields ◽  
Central Zone ◽  
Painful Stimulus ◽  
Inhibitory Zone ◽  
Sensory Afferents ◽  
Reticular Neurons

A microphysiological study of 209 neurons of the bulbopontine reticular formation was carried out in 80 "encéphales isolés" cats. After physiological stimulations of the trigeminal nerve the following conclusions were arrived at: (1) A functional arrangement exists in the lower recticular formation. Clear differences were found between the medulla and pons. (2) The pontine reticular neurons receive mostly tactile impulses from very large receptive fields. (3) The bulbar neurons receive all modalities of the trigeminal nerve from usually limited and bilateral fields (except proprioception). Pain projects mainly in this part of the reticular core. A central zone of the medulla has all physiological types of cells and is coincidental with Magoun and Rhine's inhibitory zone. (4) There was no neuronal response typical of any sensation. (5) An increase in frequency of a response was obtained in various ways: by changing the origin of the stimulus, by-increasing the intensity of the stimulus or the area of stimulation, or by applying a painful stimulus when the cell also responded to touch. (6) It is suggested that the sensory afferents lose their specificity when they reach the reticular formation but that via this formation they serve to increase awareness and perception of sensation at higher level.

Cardiac input to medullary reticular formation: neuronal responses to mechanical stimuli

1986 ◽  
Vol 251 (4) ◽  
pp. R680-R689
Author(s):  
R. W. Blair
Keyword(s):  
Reticular Formation ◽  
Sensory Modality ◽  
Receptive Fields ◽  
Arterial Occlusion ◽  
Large Mass ◽  
Mechanical Stimuli ◽  
Neuronal Responses ◽  
Medullary Reticular Formation ◽  
Discharge Rates ◽  
Reticular Neurons

Neurons in the medullary reticular formation were tested for responses to mechanical stimuli applied to the heart in cats anesthetized with chloralose and paralyzed with pancuronium. In most experiments baroreceptors were denervated. Aortic occlusion excited 15 neurons (19%) and decreased the mean discharge rates of five neurons (6%). Discrete probing of the heart elicited one to three spikes from 18 of 27 neurons tested. Thirteen of these cells had defined cardiac receptive fields; fields were large, often encompassing most of the left ventricle. Of 12 neurons tested for responses during fibrillation, 8 were excited, 2 were inhibited, and 2 were unaffected. Neurons often exhibited different sensitivities to these mechanical stimuli, as well as to ischemia produced during coronary arterial occlusion. Neurons were more likely to respond to stimuli that affected a large mass of myocardium. In addition to cardiac input, 98% of neurons in this study also received input from at least one additional sensory modality, and 39 cells were excited by somatic, auditory, and visual stimuli. Results indicate that medullary reticular neurons are responsive to mechanical events in the heart as well as to myocardial ischemia and respond to other sensory modalities.

TRIGEMINAL PROJECTIONS IN THE RETICULAR FORMATION OF THE PONS IN THE CAT

1962 ◽  
Vol 40 (1) ◽  
pp. 7-12
Author(s):  
J. M. Langlois ◽  
Guy Lamarche
Keyword(s):  
Reticular Formation ◽  
Trigeminal Nerve ◽  
Unit Activity ◽  
Functional Organization ◽  
Pontine Reticular Formation ◽  
Recording Unit ◽  
Spatial Convergence ◽  
The Face ◽  
High Degree ◽  
Stimulation Of

The projections of the trigeminal nerve in the pontine reticular formation of the cat have been investigated by recording unit activity, after physiological stimulation of the face, in 30 "encéphales isolés" preparations. No somatotopical arrangement was found but a high degree of spatial convergence onto pontine reticular units exists and a certain degree of functional organization was observed.

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.

Sensorimotor Integration at the Dorsal Column Nuclei

Physiology ◽  
1999 ◽  
Vol 14 (6) ◽  
pp. 231-237
Author(s):  
Jorge Mariño ◽  
Luis Martinez ◽  
Antonio Canedo
Keyword(s):  
Sensorimotor Integration ◽  
Receptive Fields ◽  
Central Zone ◽  
Spatial Localization ◽  
Peripheral Zone ◽  
Dorsal Column ◽  
Primary Afferents ◽  
Zone Of Inhibition ◽  
Dorsal Column Nuclei ◽  
Recurrent Collaterals

Interaction among primary afferents, corticofugal fibers, and intrinsic elements allows for sensorimotor integration at the dorsal column nuclei. The interneurons permit the spatial localization, the recurrent collaterals synchronize the activity of projecting cells with overlapping receptive fields, and the corticofugal fibers induce a central zone of activity surrounded by a peripheral zone of inhibition.

Renal and somatic input to spinal neurons antidromically activated from the ventrolateral medulla

1988 ◽  
Vol 60 (6) ◽  
pp. 1967-1981 ◽  
Author(s):  
W. S. Ammons
Keyword(s):  
Reticular Formation ◽  
Receptive Fields ◽  
Ventrolateral Medulla ◽  
Reticular Nucleus ◽  
Lateral Reticular Nucleus ◽  
Spinal Neurons ◽  
C Fiber ◽  
Somatic Input ◽  
Fiber Stimulation ◽  
Stimulation Of

1. Studies were done to characterize responses of spinal neurons backfired from the ventrolateral medulla to renal and somatic stimuli. Experiments were performed on 31 cats that were anesthetized with alpha-chloralose. Sixty-six spinal neurons were antidromically activated from the area of the lateral reticular nucleus or the ventrolateral reticular formation just rostral to the lateral reticular nucleus contralateral to the recording site. These cells could not be backfired from the medial reticular formation or from the spinothalamic tract just caudal to the thalamus. 2. Cells were located in laminae I, V, and VII of the T12-L2 segments. Antidromic conduction velocities averaged 35.9 +/- 7.2 m/s. Conduction velocities were unrelated to the projection site or laminar location of the cells. Termination sites of 21 cells were located in antidromic mapping experiments. Terminals were localized to the ventrolateral reticular formation, including the lateral reticular nucleus. 3. Responses to electrical stimulation of the renal nerves were always excitatory. Stimulation of renal A-delta-fibers excited 33 cells. These cells failed to respond to stimulation of renal C-fibers. The other 33 cells responded to both A-delta- and C-fiber stimulation. Latencies to A-delta-fiber stimulation averaged 9 +/- 2 ms, whereas latencies to C-fiber stimulation averaged 57 +/- 10 ms. 4. Renal mechanoreceptors were activated by occlusion of the renal vein or upper portion of the ureter. Renal vein occlusion excited 14 of 32 cells tested. Activity increased from 6 +/- 2 to 14 +/- 4 spike/s. Ureteral occlusion increased activity of 19 of 32 cells from 7 +/- 2 to 16 +/- 5 spikes/s. Cells responding to one of the mechanical stimuli were significantly more likely to receive A-delta-and C-fiber input compared with nonresponding cells. Nonresponders were more likely than responders to receive only A-delta input. 5. All cells received somatic input in addition to renal input. Twelve cells were classified as wide dynamic range, 46 as high threshold, and 8 as Deep. Somatic receptive fields most often included skin and muscle of the left flank and abdomen. Thirty-two cells had bilateral receptive fields, and 22 had inhibitory fields in addition to excitatory fields. 6. These data show that spinal neurons projecting to the ventrolateral medulla receive convergent inputs from the kidney and somatic structures. These cells may participate in a variety of functions including autonomic reflexes of renal origin.

Spatial determinants of multisensory integration in cat superior colliculus neurons

1996 ◽  
Vol 75 (5) ◽  
pp. 1843-1857 ◽  
Author(s):  
M. A. Meredith ◽  
B. E. Stein
Keyword(s):  
Receptive Field ◽  
Superior Colliculus ◽  
Neuronal Response ◽  
Receptive Fields ◽  
Spatial Relationship ◽  
Physiological Role ◽  
Extracellular Recording ◽  
Average Proportion ◽  
Relationship Of ◽  
High Degree

1. Although a representation of multisensory space is contained in the superior colliculus, little is known about the spatial requirements of multisensory stimuli that influence the activity of neurons here. Critical to this problem is an assessment of the registry of the different receptive fields within individual multisensory neurons. The present study was initiated to determine how closely the receptive fields of individual multisensory neurons are aligned, the physiological role of that alignment, and the possible functional consequences of inducing receptive-field misalignment. 2. Individual multisensory neurons in the superior colliculus of anesthetized, paralyzed cats were studied with the use of standard extracellular recording techniques. The receptive fields of multisensory neurons were large, as reported previously, but exhibited a surprisingly high degree of spatial coincidence. The average proportion of receptive-field overlap was 86% for the population of visual-auditory neurons sampled. 3. Because of this high degree of intersensory receptive-field correspondence, combined-modality stimuli that were coincident in space tended to fall within the excitatory regions of the receptive fields involved. The result was a significantly enhanced neuronal response in 88% of the multisensory neurons studied. If stimuli were spatially disparate, so that one fell outside its receptive field, either a decreased response occurred (56%), or no intersensory effect was apparent (44%). 4. The normal alignment of the different receptive fields of a multisensory neuron could be disrupted by passively displacing the eyes, pinnae, or limbs/body. In no case was a shift in location or size observed in a neuron's other receptive field(s) to compensate for this displacement. The physiological result of receptive-field misalignment was predictable and based on the location of the stimuli relative to the new positions of their respective receptive fields. Now, for example, one component of a spatially coincident pair of stimuli might fall outside its receptive field and inhibit the other's effects. 5. These data underscore the dependence of multisensory integrative responses on the relationship of the different stimuli to their corresponding receptive fields rather than to the spatial relationship of the stimuli to one another. Apparently, the alignment of different receptive fields for individual multisensory neurons ensures that responses to combinations of stimuli derived from the same event are integrated to increase the salience of that event. Therefore the maintenance of receptive-field alignment is critical for the appropriate integration of converging sensory signals and, ultimately, elicitation of adaptive behaviors.

Interactive effects among several stimulus parameters on the responses of striate cortical complex cells

1991 ◽  
Vol 66 (2) ◽  
pp. 379-389 ◽  
Author(s):  
T. J. Gawne ◽  
B. J. Richmond ◽  
L. M. Optican
Keyword(s):  
Striate Cortex ◽  
Neuronal Response ◽  
Receptive Fields ◽  
Response Strength ◽  
Interactive Effects ◽  
Temporal Modulation ◽  
Complex Cells ◽  
Black And White ◽  
Interaction Terms ◽  
Stimulus Parameters

1. Although neurons within the visual system are often described in terms of their responses to particular patterns such as bars and edges, they are actually sensitive to many different stimulus features, such as the luminances making up the patterns and the duration of presentation. Many different combinations of stimulus parameters can result in the same neuronal response, raising the problem of how the nervous system can extract information about visual stimuli from such inherently ambiguous responses. It has been shown that complex cells transmit significant amounts of information in the temporal modulation of their responses, raising the possibility that different stimulus parameters are encoded in different aspects of the response. To find out how much information is actually available about individual stimulus parameters, we examined the interactions among three stimulus parameters in the temporally modulated responses of striate cortical complex cells. 2. Sixteen black and white patterns were presented to two awake monkeys at each of four luminance-combinations and five durations, giving a total of 320 unique stimuli. Complex cells were recorded in layers 2 and 3 of striate cortex, with the stimuli centered on the receptive fields as determined by mapping with black and white bars. 3. An analysis of variance (ANOVA) was applied to these data with the three stimulus parameters of pattern, the luminance-combinations, and duration as the independent variables. The ANOVA was repeated with the magnitude and three different aspects of the temporal modulation of the response as the dependent variables. For the 19 neurons studied, many of the interactions between the different stimulus parameters were statistically significant. For some response measures the interactions accounted for more than one-half of the total response variance. 4. We also analyzed the stimulus-response relationships with the use of information theoretical techniques. We defined input codes on the basis of each stimulus parameter alone, as well as their combinations, and output codes on the basis of response strength, and on three measures of temporal modulation, also taken individually and together. Transmitted information was greatest when the response of a neuron was interpreted as a temporally modulated message about combinations of all three stimulus parameters. The interaction terms of the ANOVA suggest that the response of a complex cell can only be interpreted as a message about combinations of all three stimulus parameters.(ABSTRACT TRUNCATED AT 400 WORDS)

Sensitization of pelvic nerve afferents and mast cell infiltration in the urinary bladder following chronic colonic irritation is mediated by neuropeptides

2007 ◽  
Vol 292 (1) ◽  
pp. F123-F130 ◽  
Author(s):  
Elena E. Ustinova ◽  
Dmitriy W. Gutkin ◽  
Michael A. Pezzone
Keyword(s):  
Mast Cell ◽  
Urinary Bladder ◽  
Receptive Fields ◽  
Sensory Nerves ◽  
Cell Infiltration ◽  
Sprague Dawley ◽  
Trinitrobenzenesulfonic Acid ◽  
Sensory Afferents ◽  
Bladder Afferents ◽  
Irritable Bowel

Irritable bowel syndrome and interstitial cystitis frequently overlap. We have shown that acute colitis sensitizes urinary bladder afferents to both mechanical and chemical stimuli and that chronic colitis similarly produces neurogenic cystitis. We hypothesize that chronic irritation of the colon releases neuropeptides from bladder afferents, leading to receptor sensitization and neurogenic inflammation. Female Sprague-Dawley rats received intrarectal trinitrobenzenesulfonic acid (TNBS) or vehicle 3 days following either systemic capsaicin (CP) pretreatment or vehicle. Ten days later, action potentials of single-unit pelvic C-fiber afferents with receptive fields in the bladder were recorded under urethane anesthesia during graded bladder distensions (UBD) or intravesical capsaicin (vCP) administration. In controls, UBD increased bladder afferent firing in proportion to intravesical pressure. At intravesical pressures of 30 mmHg and above, the percent increase in afferent firing was significantly accentuated following TNBS compared with controls (1,222 ± 176 vs. 624 ± 54%, P < 0.01). The response to vCP was also enhanced (4,126 ± 775 vs. 1,979 ± 438%, P < 0.01). Systemic depletion of neuropeptides from sensory nerves abolished these effects. Histological examination of the bladders revealed an increase in mast cell density in TNBS-treated animals compared with controls (18.02 ± 1.25 vs. 3.11 ± 0.27 mast cells/×100 field, P < 0.01). This effect was significantly ameliorated with CP (10.25 ± 0.95, P < 0.5 vs. TNBS-treated animals). In summary, chronic colonic irritation in the rat sensitizes urinary bladder afferents to noxious stimuli and causes mast cell infiltration in the bladder. Depletion of neuropeptides from sensory afferents diminishes these effects, suggesting they play an important role.

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