scholarly journals On the presence and functional significance of sympathetic premotor neurons with collateralized spinal axons in the rat

2019 ◽  
Vol 597 (13) ◽  
pp. 3407-3423 ◽  
Author(s):  
David G. S. Farmer ◽  
Natasha Pracejus ◽  
Bowen Dempsey ◽  
Anita Turner ◽  
Phillip Bokiniec ◽  
...  
Keyword(s):  
Functional Significance ◽  
Premotor Neurons ◽  
Sympathetic Premotor Neurons

Tonic drive to sympathetic premotor neurons of rostral ventrolateral medulla from caudal pressor area neurons

1999 ◽  
Vol 276 (4) ◽  
pp. R1209-R1213 ◽  
Author(s):  
R. R. Campos ◽  
R. M. McAllen
Keyword(s):  
Blood Pressure ◽  
Significant Proportion ◽  
Rostral Ventrolateral Medulla ◽  
Ventrolateral Medulla ◽  
Cervical Cord ◽  
Neuron Activity ◽  
Tonic Activity ◽  
Premotor Neurons ◽  
Sympathetic Premotor Neurons ◽  
Caudal Pressor

The responses of sympathetic premotor neurons in the rostral ventrolateral medulla (RVLM) to activation or inactivation of neurons in the caudal pressor area (CPA) were studied in urethan-anesthetized rats. Extracellular recordings were made from 32 barosensitive single units in the RVLM, of which 26 were antidromically activated from the cervical cord. Unilateral microinjections ofl-glutamate (0.5–5 nmol) into the CPA increased firing in 13 of 14 premotor neurons by 90 ± 30% while raising blood pressure. Both ipsilateral and contralateral injections were effective. Unilateral or bilateral inhibition of CPA neuron activity by microinjecting glycine (5–200 nmol/side) lowered blood pressure, while it reduced firing in 9 of 10 and 16 of 17 premotor neurons, respectively, by 45 ± 9 and 39 ± 6%. A significant proportion of tonic activity in RVLM sympathetic premotor neurons is thus driven, directly or indirectly, by neurons in the CPA.

scholarly journals Oxidative stress in the sympathetic premotor neurons contributes to sympathetic activation in renovascular

2009 ◽  
Vol 23 (S1) ◽  
Author(s):  
Elizabeth Barbosa Oliveira‐Sales ◽  
Erika Emy Nishi ◽  
Bruno Arruda Carillo ◽  
Mirian Aparecida Boim ◽  
Miriam Sterman Dolnikoff ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Sympathetic Activation ◽  
Premotor Neurons ◽  
Sympathetic Premotor Neurons

Fractal Activity Generated Independently by Medullary Sympathetic Premotor and Preganglionic Sympathetic Neurons

2003 ◽  
Vol 90 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Hakan S. Orer ◽  
Mahasweta Das ◽  
Susan M. Barman ◽  
Gerard L. Gebber
Keyword(s):  
Spinal Cord ◽  
Power Law ◽  
Time Scale ◽  
Sympathetic Neurons ◽  
Fano Factor ◽  
Ventrolateral Medulla ◽  
Interspike Intervals ◽  
Antidromic Activation ◽  
Premotor Neurons ◽  
Sympathetic Premotor Neurons

In anesthetized cats with cervical spinal cord transection, Fano factor analysis was used to test for time-scale invariant (fractal) fluctuations in spike counts of single preganglionic cervical sympathetic neurons (PSNs) and putative sympathetic premotor neurons located in the rostral ventrolateral medulla (RVLM) and caudal medullary raphe. The medullary neurons exhibited cardiac-related activity, and their axons projected to the spinal cord, as demonstrated by antidromic activation. The variance-to-mean spike count ratio (Fano factor) was plotted as a function of the window size used to count spikes. The Fano factor curves for seven PSNs, eight RVLM neurons, and eight raphe neurons contained a power law relationship extending over more than one time scale. In these cases, random shuffling of the interspike intervals in the original time series eliminated the power law relationship. Thus the power law relationships can be attributed to long-range correlations among interspike intervals rather than simply to the distribution of the intervals that is not changed by shuffling the data. It is concluded that PSNs and sympathetic premotor neurons in the medulla can independently generate fractal firing patterns.

scholarly journals Social defeat stress induces hyperthermia through activation of thermoregulatory sympathetic premotor neurons in the medullary raphe region

2011 ◽  
Vol 34 (9) ◽  
pp. 1442-1452 ◽  
Author(s):  
Battuvshin Lkhagvasuren ◽  
Yoshiko Nakamura ◽  
Takakazu Oka ◽  
Nobuyuki Sudo ◽  
Kazuhiro Nakamura
Keyword(s):  
Social Defeat ◽  
Social Defeat Stress ◽  
Medullary Raphe ◽  
Premotor Neurons ◽  
Sympathetic Premotor Neurons

Descending vasomotor pathways from the dorsomedial hypothalamic nucleus: role of medullary raphe and RVLM

2004 ◽  
Vol 287 (4) ◽  
pp. R824-R832 ◽  
Author(s):  
J. Horiuchi ◽  
R. M. McAllen ◽  
A. M. Allen ◽  
S. Killinger ◽  
M. A. P. Fontes ◽  
...  
Keyword(s):  
Firing Rate ◽  
Acute Stress ◽  
Ventrolateral Medulla ◽  
Hypothalamic Nucleus ◽  
Modest Contribution ◽  
Medullary Raphe ◽  
Premotor Neurons ◽  
Dorsomedial Hypothalamic Nucleus ◽  
Sympathetic Premotor Neurons ◽  
Raphe Pallidus

The dorsomedial hypothalamic nucleus (DMH) is believed to play a key role in mediating vasomotor and cardiac responses evoked by an acute stress. Inhibition of neurons in the rostral ventrolateral medulla (RVLM) greatly reduces the increase in renal sympathetic nerve activity (RSNA) evoked by activation of the DMH, indicating that RVLM neurons mediate, at least in part, the vasomotor component of the DMH-evoked response. In this study, the first aim was to determine whether neurons in the medullary raphe pallidus (RP) region also contribute to the DMH-evoked vasomotor response, because it has been shown that the DMH-evoked tachycardia is mediated by the RP region. The second aim was to directly assess the effect of DMH activation on the firing rate of RVLM sympathetic premotor neurons. In urethane-anesthetized rats, injection of the GABAA receptor agonist muscimol (but not vehicle solution) in the RP region caused a modest (∼25%) but significant reduction in the increase in RSNA evoked by DMH disinhibition (by microinjection of bicuculline). In other experiments, disinhibition of the DMH resulted in a powerful excitation (increase in firing rate of ∼400%) of 5 out of 6 spinally projecting barosensitive neurons in the RVLM. The results indicate that neurons in the RP region make a modest contribution to the renal sympathoexcitatory response evoked from the DMH and also that sympathetic premotor neurons in the RVLM receive strong excitatory inputs from DMH neurons, consistent with the view that the RVLM plays a key role in mediating sympathetic vasomotor responses arising from the DMH.

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