Electrically Stimulated Increases in Cochlear Blood Flow: II. Evidence of Neural Mediation

Sillman, Jonathon S.; Masta, Robert I.; LaRouere, Michael J.; Nuttall, Alfred L.; Miller, Josef M.

doi:10.1177/019459988910100310

Cited by 12 publications

(9 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In preliminary studies we confirmed the lack of effect of systemically administered cholinergic (nicotinic and muscarinic) antagonists on the ES-evoked CBF increase as shown previously in the guinea-pig (Sillman et al 1989b). With regard to the general principle of a cholinergic receptor mediation, we note that a cholinergic response usually exhibits a fast on-off function due to the quick release of acetylcholine in the nerve endings and fast (200-300 ms) breakdown of the transmitter by acetylcholinesterase (Colquhoun, 1979).…”

Section: Discussionsupporting

confidence: 89%

“…The roles of evoked LaRouere, Masta, Miller & Nuttall, 1989a; Sillman, Masta, metabolic activity, oxygen-free radical formation, and LaRouere, Nuttall & Miller, 1989b). Increased CBF, heat in this response were examined in previous studies induced by ES, has also been reported in humans (Miller, (Sillman et al 1989b). No evidence was obtained to support All correspondence to A. L. Nuttall.…”

Section: Previous Studies Have Shown That Electrical Stimulation (Es)mentioning

confidence: 96%

“…563-573 a significant role for any of these factors. Only pharmacological blockade of all autonomic, afferent and efferent fibres in the cochlea by tetrodotoxin applied to the round window (RW) eliminated the response (Sillman et al 1989b), indicating that the response is neurally mediated.…”

Section: Previous Studies Have Shown That Electrical Stimulation (Es)mentioning

confidence: 99%

See 2 more Smart Citations

Neuronal regulation of cochlear blood flow in the guinea‐pig.

Laurikainen

Costa

Miller

et al. 1994

The Journal of Physiology

View full text Add to dashboard Cite

Previous studies have shown that electrical stimulation (ES) of the guinea-pig cochleacauses a neurally mediated increase in cochlear blood flow (CBF). It is known that the centrifugal neuronal input to the cochlea comes through the perivascular sympathetic plexus from the cervical sympathetic chain and along the vestibular nerve (VN) from the periolivary area of the brainstem. Both of these neuronal systems are distributed topographically in the cochlea. 2. In order to study the neural origins of ES-evoked CBF increase, laser Doppler flowmetry was used to test the following hypotheses. (a) The response is regional, that is, limited to the area of the cochlea stimulated. To test this we performed differential ES of the cochlear turns. CBF was measured from either the third or the first turn.(b) The response is mediated via autonomic receptors within the cochlea. To study this, we applied atropine, succinylcholine and idazoxan locally to the cochlea. (c) The response is influenced by neuronal input via the sympathetic cervical chain (SC) and components of the VN. We stimulated and sectioned the SC, and sectioned the VN, to test this hypothesis. 3. We observed that the CBF response was topographically restricted to the stimulated region. Locally applied muscarinic or nicotinic antagonists (atropine and succinylcholine respectively) did not affect the response. However, local idazoxan (an a2-blocker) eliminated the response. Locally applied adrenaline and SC stimulation modified the dynamic range of the response. SC sectioning enhanced the responsiveness of the cochlear vasculature to ES. The VN section caused a temporary decrease in CBF and elimination of the ES-evoked CBF response. 4. We conclude that the release of dilating agents is topographical with respect to ES current flow, the ES-evoked CBF increase is peripherally mediated via a2-receptors, and the response is influenced by input via the SC. The elimination of the response by VN sectioning proximal to the brainstem indicated that fibres of the VN mediate the CBF increase during direct cochlear ES. The data suggest that these fibres may be the efferent limb of a neural loop involved with the regulation of CBF. Such a system could provide a mechanism for the rapid increase in CBF with organ stress.Electrical stimulation (ES) of the guinea-pig cochlea causes Bredberg, Grenman, Suonpiiii, Lindstrom & Didier, 1991). an increase in cochlear blood flow (CBF) as measured by The evoked response appears to be neurally mediated, and the laser Doppler flowmeter (LDF) or intravital microscopy it is maximized by an appropriate combination of

show abstract

Section: Discussionsupporting

confidence: 89%

Section: Previous Studies Have Shown That Electrical Stimulation (Es)mentioning

confidence: 96%

See 1 more Smart Citation

Neuronal regulation of cochlear blood flow in the guinea‐pig.

Laurikainen

Costa

Miller

et al. 1994

The Journal of Physiology

View full text Add to dashboard Cite

show abstract

“…The normal function of the cochlea relies very much on both the intracellular and extracellular milieu, particularly the cochlear microcirculation [12]. The cochlea receives its blood supply mainly from the labyrinthine artery without shunting from collateral vasculature.…”

Section: Discussionmentioning

confidence: 99%

A clinical study of microcirculatory disturbance in Chinese patients with sudden deafness

Lu¹,

Jin²,

Tong³

et al. 2008

Acta Oto-Laryngologica

View full text Add to dashboard Cite

The levels of total cholesterol (TCH), triglyceride (TG), and lipoprotein A were significantly higher in patients with sudden deafness than in control subjects. Plasma viscosity, ratio viscosity of whole blood, reduced viscosity of whole blood, high and low shear relative viscosity of whole blood, index of red blood cells transmutation, and fibrinogen level in the plasma of patients with sudden sensorineural hearing loss (SSNHL) were also significantly elevated in comparison with those in control subjects. White-collar workers with psychological and behavioral abnormalities tend to suffer from sudden deafness.

show abstract

“…Autoregulatory capabilities of the cochlear blood fl ow occur through the control of inner ear vasculature [Ren et al, 1994], sympathetic input to the cochlea [Carrasco et al, 1990;Laurikainen et al, 1993;Ren et al, 1993a, b] and the infl uence of various circulating vasoactive hormones and transmitters [Wright et al, 1985;Short et al, 1985;Miller et al, 1986;Sillman et al, 1989;Quirk et al, 1988;Ohlsen et al, 1991]. The aged ear has less capacity to maintain stable blood fl ow and thus may be more vulnerable to stress factors that affect cochlear function [Nakashima et al, 1995;Suzuki et al, 1998], starting with defi cits in OHCs.…”

Section: Teoae and Dpoae Amplitudesmentioning

confidence: 99%

Loss of Peripheral Right-Ear Advantage in Age-Related Hearing Loss

et al. 2004

View full text Add to dashboard Cite

In young adults with normal hearing, the right ear is more sensitive than the left to simple sounds (peripheral right-ear advantage) and to processing complex sounds such as speech (central right-ear advantage). In the present investigation, the effects of hearing loss and aging on this auditory asymmetry were examined at both peripheral and central levels. Audiograms and transient evoked otoacoustic emission (TEOAE) and distortion product otoacoustic emission amplitudes were used to assess cochlear function. The contralateral suppression of TEOAEs was measured to assess the medial olivocochlear efferent system. The Hearing in Noise Test (HINT; binaural speech) was conducted to assess higher central auditory function. A group of aged subjects with normal hearing (flat audiograms) were compared to a group of aged subjects with sloping audiograms (presbycusis). At the cochlear (peripheral) level, the normal hearing group showed significantly higher otoacoustic emission amplitudes for the right ear compared to the left ear, which is consistent with the right-ear dominance normally seen in young adults. However, this finding was reversed in the presbycusic group that showed higher left-ear emission amplitudes. At the brainstem level, the amplitudes of TEOAE contralateral suppression were small and no significant difference was found between the right and left ears in both groups. On the contrary, HINT results showed a continuous dominance of the right ear (left hemisphere) in both groups, which was consistent with previous reports showing that the right hemisphere is more affected by age than the left hemisphere.

show abstract

Electrically Stimulated Increases in Cochlear Blood Flow: II. Evidence of Neural Mediation

Cited by 12 publications

References 24 publications

Neuronal regulation of cochlear blood flow in the guinea‐pig.

Neuronal regulation of cochlear blood flow in the guinea‐pig.

A clinical study of microcirculatory disturbance in Chinese patients with sudden deafness

Loss of Peripheral Right-Ear Advantage in Age-Related Hearing Loss

Contact Info

Product

Resources

About