scholarly journals Responses of muscle spindles in feline dorsal neck muscles to electrical stimulation of the cervical sympathetic nerve

2005 ◽  
Vol 168 (1-2) ◽  
pp. 312-312
Author(s):  
F. Hellström ◽  
S. Roatta ◽  
J. Thunberg ◽  
M. Passatore ◽  
M. Djupsjöbacka
Keyword(s):  
Electrical Stimulation ◽  
Sympathetic Nerve ◽  
Muscle Spindles ◽  
Neck Muscles ◽  
Cervical Sympathetic ◽  
Cervical Sympathetic Nerve ◽  
Stimulation Of

Cotransmission from sympathetic vasoconstrictor neurons to small cutaneous arteries in vivo

1999 ◽  
Vol 277 (1) ◽  
pp. H58-H64 ◽  
Author(s):  
Judy L. Morris
Keyword(s):  
Image Analysis ◽  
Electrical Stimulation ◽  
Guinea Pig ◽  
Neuropeptide Y ◽  
Adrenoceptor Antagonist ◽  
On Line ◽  
Cervical Sympathetic ◽  
Cervical Sympathetic Nerve ◽  
Stimulation Of

This study has characterized constrictions of small cutaneous arteries in the guinea pig ear in response to electrical stimulation of the cervical sympathetic nerve (SNS) in vivo. Video microscopy and on-line image analysis were used to examine diameter changes of ear arteries (80–140 μm resting diameter) in anesthetized guinea pigs. Trains of 50–300 impulses, but not single pulses or short trains, produced frequency-dependent (2–20 Hz) constrictions. The purinoceptor antagonist suramin (30 μM) greatly reduced constrictions produced by exogenous ATP but did not affect constrictions produced by SNS at 10 Hz or exogenous norepinephrine. The α2-adrenoceptor antagonist yohimbine (1 μM) enhanced the peak amplitude of sympathetic constrictions at lower stimulation frequencies (1–5 Hz). The amplitude of constrictions to SNS at 10 Hz was reduced, and the latency of constrictions was increased by the α1-adrenoceptor antagonist prazosin (1 μM). Constrictions to SNS at 10 Hz remaining after prazosin treatment were reduced in amplitude by dihydroergotamine (2 μM) and were attenuated further by the neuropeptide Y Y1-receptor antagonist 1229U91 (0.3 μM). Thus norepinephrine and neuropeptide Y act as cotransmitters to mediate sympathetic constriction of small ear arteries at higher stimulation frequencies (10 Hz), but ATP does not seem to contribute directly to these constrictions.

scholarly journals Global Cerebral Vasodilatation Elicited by Focal Electrical Stimulation within the Dorsal Medullary Reticular Formation in Anesthetized Rat

1983 ◽  
Vol 3 (3) ◽  
pp. 270-279 ◽  
Author(s):  
Costantino Iadecola ◽  
Masatsugu Nakai ◽  
Ehud Arbit ◽  
Donald J. Reis
Keyword(s):  
Electrical Stimulation ◽  
Reticular Formation ◽  
Medial Longitudinal Fasciculus ◽  
Medullary Reticular Formation ◽  
Tissue Samples ◽  
The Central Nervous System ◽  
Cerebral Vasodilatation ◽  
Cervical Sympathetic ◽  
Global Increase ◽  
Stimulation Of

We examined the effects of electrical stimulation of a restricted area of the dorsal medullary reticular formation (DMRF) on regional cerebral blood flow (CBF) in anesthetized (by chloralose), paralyzed (by curare) rats. CBF was measured in tissue samples by the Kety principle, with 14C-iodoantipyrine as indicator. Stimulation of DMRF elicited a widespread, significant increase in CBF in 12 of 13 areas. The increase in flow was greatest in cerebral cortex, up to 240% of control. However, it was also substantially increased in selected regions of telencephalon, diencephalon, mesencephalon, and lower brainstem, but not cerebellum. In contrast, electrical stimulation of the midline (interstitial nucleus of the medial longitudinal fasciculus) 1 mm medial to the DMRF did not change CBF. The increase in CBF evoked by DMRF stimulation persisted after transection of the spinal cord at C1 or cervical sympathetic trunk. We conclude that excitation of neurons originating in or passing through the DMRF can elicit a potent and virtually global increase of CBF. The effect appears to be mediated by intrinsic pathways of the central nervous system.

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