Tonic descending modulation of spinal neuronal responses to activation of renal receptors

Experiments were conducted in anesthetized cats to determine if spinal neuronal responses to activation of renal receptors are tonically modulated by descending spinal pathways. Eighty-seven thoracolumbar spinal neurons with renal and somatic input were tested for responses to occlusion of the renal vein, renal artery, and ureter before, during, and after cooling the spinal cord rostral to the recording site. Cooling increased the number of neurons that responded as well as the magnitude of the responses to renal vein (RVO), renal artery (RAO), and ureteral occlusion (UO). RVO increased cell activity of 21 neurons from 12.5 +/- 2.7 to 31.7 +/- 6.0 spikes/s during cooling. UO increased cell activity of 24 neurons from 9.0 +/- 2.1 before cooling to 25.0 +/- 4.9 spikes/s during cooling. Cold block increased the magnitude of both types of responses to RAO that were due to mechanical deformation of the renal artery and prolonged renal ischemia. These data show that the majority of spinal neuronal responses to renal receptor stimulation are modulated by tonic inhibitory influences. Thus these results provide a mechanism by which the brain may control spinal circuitry that underlies reflexes of renal origin.

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Effects of renal receptor stimulation on neurons within the ventrolateral medulla of the cat

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1993.265.2.r290 ◽

1993 ◽

Vol 265 (2) ◽

pp. R290-R301 ◽

Cited By ~ 2

Author(s):

M. A. Vizzard ◽

A. Standish ◽

W. S. Ammons

Keyword(s):

Renal Artery ◽

Renal Vein ◽

Receptor Activation ◽

Artery Occlusion ◽

Ventrolateral Medulla ◽

Receptor Stimulation ◽

Renal Artery Occlusion ◽

Renal Receptor ◽

Excitatory Responses ◽

Alpha Chloralose

Experiments were performed to determine if activation of renal receptors by occlusion of the renal artery, renal vein, or ureter would alter activity of cells within the ventrolateral medulla of the cat. Extracellular unit recordings were obtained from 195 cells located within the rostral ventrolateral medulla of 90 alpha-chloralose-anesthetized cats. Fifty-five of 195 cells (28.2%) tested for responses to renal receptor activation responded to at least one of the occlusions. Occlusion of the ureter increased the activity of 25 cells from 9.7 +/- 3.7 to 23.0 +/- 6.5 impulses/s and decreased the activity of 5 cells from 11.9 +/- 3.6 to 3.5 +/- 1.2 impulses/s. Occlusion of the renal vein increased the activity of seven cells from 7.5 +/- 3.3 to 22.3 +/- 7.3 impulses/s and decreased the activity of six cells from 13.8 +/- 3.8 to 4.1 +/- 2.0 impulses/s. Renal artery occlusion elicited solely excitatory responses from 43 cells. Thirty-one of the 43 cells increased their activity within 0-3 s of the onset of renal artery occlusion from 4.1 +/- 0.8 to 12.6 +/- 1.2 impulses/s. Renal artery occlusion increased the activity of 10 out of 43 cells with a mean latency of 26.1 +/- 6.5 s from 8.3 +/- 2.5 to 29.6 +/- 9.3 impulses/s. Twenty-four of the 55 (43.6%) responders were responsive to two or more forms of renal receptor activation. These results demonstrate that activation of renal mechanoreceptors and chemoreceptors affects cells within the ventrolateral medulla of the cat.(ABSTRACT TRUNCATED AT 250 WORDS)

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Spinal Neuronal Responses to Urinary Bladder Stimulation in Rats With Corticosterone or Aldosterone Onto the Amygdala

Journal of Neurophysiology ◽

10.1152/jn.00298.2003 ◽

2003 ◽

Vol 90 (4) ◽

pp. 2180-2189 ◽

Cited By ~ 21

Author(s):

Chao Qin ◽

Beverley Greenwood-Van Meerveld ◽

Robert D. Foreman

Keyword(s):

Urinary Bladder ◽

Dorsal Margin ◽

Neuronal Responses ◽

Spinal Neurons ◽

Excitatory Response ◽

Fischer 344 ◽

Descending Modulation ◽

Bladder Afferents ◽

Left And Right ◽

Excitatory Responses

Elevating glucocorticoids in the amygdala produces colorectal hypersensitivity through activation of lumbosacral spinal neurons. The aim of this study was to determine if descending modulation from the amygdala affects spinal processing of input from urinary bladder afferents. Fischer-344 rats received cholesterol (inactive control)-, corticosterone-, or aldosterone-containing micropellets placed stereotaxically on the dorsal margin of the left and right amygdala ( n = 10 for each group). Seven days after amygdaloid implantation, extracellular potentials of single L6–S1 spinal neurons were examined for the responses to graded (0.5–2.0 ml, 20 s) urinary bladder distension (UBD). Spontaneous activity of neurons with excitatory responses to UBD in aldosterone-implanted rats [11.0 ± 1.7 (SE) imp/s], but not in corticosterone-implanted rats, was higher than in the cholesterol-implanted group (6.6 ± 1.1 imp/s, P < 0.05). Noxious UBD (1.5 ml) produced a greater excitatory response (21.6 ± 2.6 imp/s) in aldosterone-implanted rats compared with cholesterol- or corticosterone-implanted rats (15.1 ± 1.5 and 13.6 ± 1.4 imp/s; P < 0.05). In contrast, the duration of excitatory responses to UBD in corticosterone-implanted rats (38.5 ± 3.4 imp/s) was significantly longer than those in the aldosterone or control groups (26.8 ± 1.8 and 24.7 ± 1.5 imp/s). Neurons with low thresholds for excitatory responses to UBD were seen more frequently in aldosterone-implanted rats than in corticosterone or cholesterol treated rats (74 vs. 44% and 39%, P < 0.05). No difference in somatic field properties of spinal neurons responsive or nonresponsive to UBD was found among the three groups. These findings suggest that both mineralocorticoid- and glucocorticoid-mediated mechanisms in the amygdala are involved in descending modulation to lumbosacral spinal neurons receiving inputs from the urinary bladder; and this mechanism may play a role in the activation and maintenance of primary central sensitization to noxious visceral stimuli.

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Renal vein cytokine release as an index of renal parenchymal inflammation in chronic experimental renal artery stenosis

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gft305 ◽

2013 ◽

Vol 29 (2) ◽

pp. 274-282 ◽

Cited By ~ 29

Author(s):

Alfonso Eirin ◽

Xin Zhang ◽

Xiang-Yang Zhu ◽

Hui Tang ◽

Kyra L. Jordan ◽

...

Keyword(s):

Renal Artery ◽

Renal Artery Stenosis ◽

Renal Vein ◽

Artery Stenosis ◽

Cytokine Release

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RENOVASCULAR HYPERTENSION IN CHILDREN

PEDIATRICS ◽

10.1542/peds.46.3.362 ◽

1970 ◽

Vol 46 (3) ◽

pp. 362-370

Author(s):

Ernst P. Leumann ◽

Robert P. Bauer ◽

Paul E. Slaton ◽

Edward G. Biglieri ◽

Malcolm A. Holliday

Keyword(s):

Renal Artery ◽

Renal Artery Stenosis ◽

Renovascular Hypertension ◽

Pediatric Patient ◽

Renal Vein ◽

Diagnostic Problem ◽

Bilateral Renal Artery Stenosis ◽

Bilateral Renal Artery ◽

Fibromuscular Hyperplasia ◽

Hypertension In Children

Three children with renovascular hypertension are presented in order to demonstrate the wide clinical spectrum of this disease. Two patients had relatively minor symptoms, but one with neurofibromatosis showed frank hypokalemia, polyuria, and hyponatremia. Three different anatomical lesions were found: bilateral renal artery stenosis in the patient with neurofibromatosis, fibromuscular hyperplasia in the patient with stenosis of one renal artery, and an isolated malformation of one small intrarenal artery. The last of our patients presented a complicated diagnostic problem which required repeated arteriograms and renal vein catheterizations for differential renin assay. Renovascular hypertension should be excluded in any pediatric patient with otherwise unexplained hypertension.

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Efficient generation of reciprocal signals by inhibition

Journal of Neurophysiology ◽

10.1152/jn.00083.2012 ◽

2012 ◽

Vol 107 (9) ◽

pp. 2453-2462 ◽

Cited By ~ 11

Author(s):

Sung-min Park ◽

Esra Tara ◽

Kamran Khodakhah

Keyword(s):

Purkinje Cells ◽

Granule Cell ◽

Granule Cells ◽

Mossy Fiber ◽

Cell Activity ◽

Common Mechanism ◽

Input Output ◽

Firing Rates ◽

Neuronal Computation ◽

The Brain

Reciprocal activity between populations of neurons has been widely observed in the brain and is essential for neuronal computation. The different mechanisms by which reciprocal neuronal activity is generated remain to be established. A common motif in neuronal circuits is the presence of afferents that provide excitation to one set of principal neurons and, via interneurons, inhibition to a second set of principal neurons. This circuitry can be the substrate for generation of reciprocal signals. Here we demonstrate that this equivalent circuit in the cerebellar cortex enables the reciprocal firing rates of Purkinje cells to be efficiently generated from a common set of mossy fiber inputs. The activity of a mossy fiber is relayed to Purkinje cells positioned immediately above it by excitatory granule cells. The firing rates of these Purkinje cells increase as a linear function of mossy fiber, and thus granule cell, activity. In addition to exciting Purkinje cells positioned immediately above it, the activity of a mossy fiber is relayed to laterally positioned Purkinje cells by a disynaptic granule cell → molecular layer interneuron pathway. Here we show in acutely prepared cerebellar slices that the input-output relationship of these laterally positioned Purkinje cells is linear and reciprocal to the first set. A similar linear input-output relationship between decreases in Purkinje cell firing and strength of stimulation of laterally positioned granule cells was also observed in vivo. Use of interneurons to generate reciprocal firing rates may be a common mechanism by which the brain generates reciprocal signals.

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Re: Main Renal Artery Clamping with or without Renal Vein Clamping during Robotic Partial Nephrectomy for Clinical T1 Renal Masses: Perioperative and Long-Term Functional Outcomes

The Journal of Urology ◽

10.1016/j.juro.2016.12.102 ◽

2017 ◽

Vol 197 (4) ◽

pp. 1000-1001

Author(s):

Jeffrey A. Cadeddu

Keyword(s):

Renal Artery ◽

Partial Nephrectomy ◽

Renal Vein ◽

Functional Outcomes ◽

Robotic Partial Nephrectomy ◽

Renal Masses ◽

Main Renal Artery

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Backward walking highlights gait asymmetries in children with cerebral palsy

Journal of Neurophysiology ◽

10.1152/jn.00679.2017 ◽

2018 ◽

Vol 119 (3) ◽

pp. 1153-1165 ◽

Cited By ~ 12

Author(s):

Germana Cappellini ◽

Francesca Sylos-Labini ◽

Michael J. MacLellan ◽

Annalisa Sacco ◽

Daniela Morelli ◽

...

Keyword(s):

Cerebral Palsy ◽

Muscle Activation ◽

Pattern Generation ◽

Comprehensive Assessment ◽

Emg Activity ◽

Backward Walking ◽

Spinal Circuitry ◽

Children With Cerebral Palsy ◽

Control Circuits ◽

The Brain

To investigate how early injuries to developing motor regions of the brain affect different forms of gait, we compared the spatiotemporal locomotor patterns during forward (FW) and backward (BW) walking in children with cerebral palsy (CP). Bilateral gait kinematics and EMG activity of 11 pairs of leg muscles were recorded in 14 children with CP (9 diplegic, 5 hemiplegic; 3.0–11.1 yr) and 14 typically developing (TD) children (3.3–11.8 yr). During BW, children with CP showed a significant increase of gait asymmetry in foot trajectory characteristics and limb intersegmental coordination. Furthermore, gait asymmetries, which were not evident during FW in diplegic children, became evident during BW. Factorization of the EMG signals revealed a comparable structure of the motor output during FW and BW in all groups of children, but we found differences in the basic temporal activation patterns. Overall, the results are consistent with the idea that both forms of gait share pattern generation control circuits providing similar (though reversed) kinematic patterns. However, BW requires different muscle activation timings associated with muscle modules, highlighting subtle gait asymmetries in diplegic children, and thus provides a more comprehensive assessment of gait pathology in children with CP. The findings suggest that spatiotemporal asymmetry assessments during BW might reflect an impaired state and/or descending control of the spinal locomotor circuitry and can be used for diagnostic purposes and as complementary markers of gait recovery.NEW & NOTEWORTHY Early injuries to developing motor regions of the brain affect both forward progression and other forms of gait. In particular, backward walking highlights prominent gait asymmetries in children with hemiplegia and diplegia from cerebral palsy and can give a more comprehensive assessment of gait pathology. The observed spatiotemporal asymmetry assessments may reflect both impaired supraspinal control and impaired state of the spinal circuitry.

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Pre-stimulus phase and amplitude regulation of phase-locked responses are maximized in the critical state

eLife ◽

10.7554/elife.53016 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 1

Author(s):

Arthur-Ervin Avramiea ◽

Richard Hardstone ◽

Jan-Matthis Lueckmann ◽

Jan Bím ◽

Huibert D Mansvelder ◽

...

Keyword(s):

Computational Model ◽

Critical State ◽

Global Dynamics ◽

Critical Dynamics ◽

Neuronal Responses ◽

Scale Free ◽

Stimulus Response ◽

Functional States ◽

The Brain

Understanding why identical stimuli give differing neuronal responses and percepts is a central challenge in research on attention and consciousness. Ongoing oscillations reflect functional states that bias processing of incoming signals through amplitude and phase. It is not known, however, whether the effect of phase or amplitude on stimulus processing depends on the long-term global dynamics of the networks generating the oscillations. Here, we show, using a computational model, that the ability of networks to regulate stimulus response based on pre-stimulus activity requires near-critical dynamics—a dynamical state that emerges from networks with balanced excitation and inhibition, and that is characterized by scale-free fluctuations. We also find that networks exhibiting critical oscillations produce differing responses to the largest range of stimulus intensities. Thus, the brain may bring its dynamics close to the critical state whenever such network versatility is required.

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