Effects of Electrical Stimulation of the Superior Cervical Ganglion on Cochlear Blood Flow in Guinea Pig

Laser Doppler flowmetry was used to assess cochlear blood flow (CBF) in the hydropic ear in four experiments. 1) The increase in CBF elicited by local electrical stimulation of the cochlea in the hydropic ear was compared to that observed in normal controls. The magnitude of the evoked CBF change was reduced by approximately 30% in the hydropic ear compared to the normal ear. 2) The reduction in CBF evoked by direct electrical stimulation of the superior cervical ganglion was reduced by approximately one third in the hydropic ear compared to a normal ear. 3) Rhythmic (flux motion or vasomotion) variations in CBF, observed in association with lower blood pressure and thought to extend the autoregulatory range in an organ system, were reduced or eliminated in the hydropic ear. 4) The autoregulatory response to a decreased perfusion pressure, produced by decreased cardiac output, was clearly reduced relative to control in the hydropic ear. These findings represent the first report of significant CBF changes with hydrops. They are consistent with reports of increased sensitivity of the hydropic ear to trauma and stress and may be relevant considerations in the treatment of hydrops in humans.

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Effects of Stellate Ganglion Stimulation on Bilateral Cochlear Blood Flow

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348949310200511 ◽

1993 ◽

Vol 102 (5) ◽

pp. 378-384 ◽

Cited By ~ 32

Author(s):

Tianying Ren ◽

Esa Laurikainen ◽

Wayne S. Quirk ◽

Josef M. Miller ◽

Alfred L. Nuttall

Keyword(s):

Blood Flow ◽

Superior Cervical Ganglion ◽

Stellate Ganglion ◽

Systemic Blood Pressure ◽

Nerve Fibers ◽

Cochlear Blood Flow ◽

Doppler Flowmetry ◽

Cervical Ganglion ◽

Pass Through ◽

Stimulation Of

The effect of intraneural electrical stimulation of the stellate ganglion (SG) on bilateral cochlear blood flow (CBF) was investigated with laser-Doppler flowmetry. The SG of 15 anesthetized guinea pigs was exposed by a novel surgical approach and stimulated with a specially designed intraneural bipolar platinum-iridium electrode. Bilateral CBF was continuously monitored. Stimulation of 0.25 mA caused a detectable increase of the systemic blood pressure (BP) and a bilateral decrease of the cochlear vascular conductance (R, defined as the ratio CBF/BP). A stimulus of 0.5 mA elicited a statistically significant ipsilateral CBF (CBFi) decrease of 3.6% ± 5.1% from the baseline and a contralateral CBF (CBFc) decrease of 3.1% ± 5.5%. That no statistical difference was found between CBFi and CBFc indicates that a unilateral sympathetic stimulation of the SG can cause equal bilateral responses. These responses were accompanied by a significantly increased BP (8.7% ± 5.2% of baseline) and consequently a greatly decreased R (12.2% ± 6.5%) of the ipsilateral cochlea. Bilateral sections of the cervical sympathetic trunk below the level of the superior cervical ganglion did not alter the evoked changes in CBF, BP, and R. It is concluded that SG stimulation can decrease the conductivity of the cochlear vessels or the supplying vessels of the cochlea. Additionally, the SG nerve fibers that cause these effects do not pass through the superior cervical ganglion.

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Sinusal afferents supplying superior cervical ganglion

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1982.242.2.h168 ◽

1982 ◽

Vol 242 (2) ◽

pp. H168-H171

Author(s):

R. S. Tuttle ◽

M. McCleary

Keyword(s):

Electrical Stimulation ◽

Superior Cervical Ganglion ◽

Carotid Sinus ◽

Morphological Characteristics ◽

Sympathetic Trunk ◽

Inhibitory Input ◽

Related Activity ◽

Cervical Ganglion ◽

Cardiac Pulse ◽

Stimulation Of

Sinusal distension can evoke activity in nerves supplying the superior cervical ganglion. These nerves, which have been shown to have little depressor influence, may carry an inhibitory input from the carotid sinus to the superior cervical ganglion (SCG). They have the morphological characteristics of the nerve of Hering and show cardiac pulse-related activity that may reach a maximum of 50 impulses/s during distension of the sinus. Electrical stimulation of the ascending preganglionic sympathetic trunk supplying the SCG may evoke discreet bursts of activity in these fibers, which do not summate with continued stimulation.

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The effect of preganglionic stimulation on the incorporation of l-[U-14C]valine into the protein of the superior cervical ganglion of the guinea pig

Biochemical Journal ◽

10.1042/bj1180813 ◽

1970 ◽

Vol 118 (5) ◽

pp. 813-818 ◽

Cited By ~ 9

Author(s):

P. Banks

Keyword(s):

Guinea Pig ◽

Superior Cervical Ganglion ◽

Superior Cervical Ganglia ◽

Cervical Ganglion ◽

Cervical Ganglia ◽

Preganglionic Stimulation ◽

Energy Dependent ◽

Stimulation Of

1. Superior cervical ganglia from the guinea pig carry out an energy-dependent incorporation of l-[14C]valine into protein in vitro. 2. Stimulation of the preganglionic nerve at a physiological frequency for more than a few minutes decreases the ability of the ganglia to incorporate labelled valine into protein.

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