PMID- 9745962
OWN - NLM
STAT- MEDLINE
DCOM- 19981130
LR  - 20190822
IS  - 0378-5955 (Print)
IS  - 0378-5955 (Linking)
VI  - 123
IP  - 1-2
DP  - 1998 Sep
TI  - Longitudinal endolymph movements induced by perilymphatic injections.
PG  - 137-47
AB  - Endolymph movements and endocochlear potential (EP) changes were measured during 
      disturbances of perilymphatic pressure. induced by injecting artificial perilymph 
      into scala tympani (ST) or scala vestibuli (SV) of the guinea pig cochlea. 
      Injections were performed either with or without an outlet made in the opposite 
      perilymphatic scala. Injections into ST without an outlet induced large pressure 
      changes but virtually no endolymph movement or EP change. Injection at the same 
      rate into ST with an outlet in SV produced smaller pressure changes which were 
      accompanied by a basally-directed displacement of endolymph and significant EP 
      changes. The magnitude of endolymph displacements and EP changes varied as a 
      function of injection rate. Injections into SV, either with or without an outlet 
      in ST, produced apically-directed endolymph displacement and EP changes. For the 
      SV injections without an outlet, the cochlear aqueduct and round window are 
      likely to provide an outlet and compliance, permitting flow along the 
      perilymphatic scalae to occur even when no ST outlet was provided. We conclude 
      that endolymph movements are not dependent on the absolute pressure of the 
      perilymph, but instead occur when small, sustained pressure gradients are present 
      across the cochlear partition, corresponding to times when perilymph flow is 
      induced. This study demonstrates that in the normal. sealed cochlea, endolymph 
      and EP are insensitive to fluid injections into ST, but are sensitive to fluid 
      injections into SV. Endolymph movements are therefore unlikely to be generated by 
      cerebrospinal fluid pressure fluctuations (such as those produced by respiration, 
      posture changes, coughing, sneezing, etc) which are transmitted to ST by the 
      cochlear aqueduct.
FAU - Salt, A N
AU  - Salt AN
AD  - Department of Otolaryngology, Washington University School of Medicine, St. 
      Louis, MO 63110, USA. salt_a@kids.wustl.edu
FAU - DeMott, J E
AU  - DeMott JE
LA  - eng
GR  - DC 01368/DC/NIDCD NIH HHS/United States
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - Netherlands
TA  - Hear Res
JT  - Hearing research
JID - 7900445
SB  - IM
MH  - Animals
MH  - Cerebrospinal Fluid/*physiology
MH  - Cochlear Duct/physiology
MH  - Endolymph/*physiology
MH  - Endolymphatic Hydrops/etiology
MH  - Guinea Pigs
MH  - Perilymph
MH  - Pressure
MH  - Scala Tympani/*physiology
EDAT- 1998/09/24 00:00
MHDA- 1998/09/24 00:01
CRDT- 1998/09/24 00:00
PHST- 1998/09/24 00:00 [pubmed]
PHST- 1998/09/24 00:01 [medline]
PHST- 1998/09/24 00:00 [entrez]
AID - S0378-5955(98)00106-3 [pii]
AID - 10.1016/s0378-5955(98)00106-3 [doi]
PST - ppublish
SO  - Hear Res. 1998 Sep;123(1-2):137-47. doi: 10.1016/s0378-5955(98)00106-3.