Objective To record the endocochlear potential (EP) and calculate potassium concentration [K+] in Minipig cochleae. Methods We used multi-barreled electrodes to measure the EP and the potential, [K + ]. EP and potassi...Objective To record the endocochlear potential (EP) and calculate potassium concentration [K+] in Minipig cochleae. Methods We used multi-barreled electrodes to measure the EP and the potential, [K + ]. EP and potassium electrode recording were made in 9 cochleae from 5 minipigs to get normal EP values. Results The average EP value in the cochlea from the minipigs was 77.3 ± 14 mV. The average [K+] for the minipigs was 147.1 ± 13 mM. Conclusions The EP and potential, [K + ] in minipigs are lower than in the human and rodents. This may be the reason why porcine ABR thresholds are slightly higher than humans and rodents.展开更多
Mini pig models are large mammals and their ears are more similar with human beings in structure and development than other animals.However,the study on porcine ears is still in the initial stage and there is no descr...Mini pig models are large mammals and their ears are more similar with human beings in structure and development than other animals.However,the study on porcine ears is still in the initial stage and there is no description of an ideal operation approach to endocochlear potential and potassium ion concentration measurements.In this article,we describe a pre-auricular surgical approach to access the middle and inner ear for endocochlear potential and potassium ion concentration measures in mini pig models.Ten one-week old normal mini pigs were used in the study.The bulla of the temporal bone was accessed via a pre-auricular approach for endocochlear potential and potassium ion concentration measurements.The condition of the animals during the first post—experiment 24 h was observed.One animal died during surgery.The preauricular approach improved protection and preservation of relevant nervous and vascular elements including the facial nerve and carotid artery.So,the pre-auricular approach can be used for endocochlear potential and potassium ion concentration measurements with improved nerve and artery preservation mini pigs.展开更多
To assess the relationship between cochlear blood flow (CBF) and auditory function, a procedure of intravital microscopy for observations of the lateral wall vessels of the cochlea coupled with the simultaneous measur...To assess the relationship between cochlear blood flow (CBF) and auditory function, a procedure of intravital microscopy for observations of the lateral wall vessels of the cochlea coupled with the simultaneous measurement of the endocochlear potential (EP) was established in guinea pigs with gradual ischemia of the cochlea. It was found that occlusions of both common carotid arteries and one of the vertebral arteries produced a minor reduction in CBF with no significant alteration in the EP. When intravenous infusion of ATP induced sharp and severe decreases in CBF, the EP varied only slightly from the baseline in some animals while there were no alteration in others. Furthermore, ATP infusions combined with arterial occlusions caused even more severe declines in CBF and a moderate decrease in the EP. The results indicate that not only does the CBF satisfy the basic needs of the processes of cochlear function, but also has a regulatory mechanism to ensure the normal function of the cochlea in the ischemia condition. It was also found that the changes in the stria vascularis vessels induced by decreases in blood pressure (BP) and heart rates were more severe than those of the spiral ligament vessels. This phenomenon indicated that the stria vascularis vessels were more sensitive to decreases of BP and heart rates.展开更多
文摘Objective To record the endocochlear potential (EP) and calculate potassium concentration [K+] in Minipig cochleae. Methods We used multi-barreled electrodes to measure the EP and the potential, [K + ]. EP and potassium electrode recording were made in 9 cochleae from 5 minipigs to get normal EP values. Results The average EP value in the cochlea from the minipigs was 77.3 ± 14 mV. The average [K+] for the minipigs was 147.1 ± 13 mM. Conclusions The EP and potential, [K + ] in minipigs are lower than in the human and rodents. This may be the reason why porcine ABR thresholds are slightly higher than humans and rodents.
基金supported by grants from the National Basic Research Program of China(973 Program)(2012CB967900. 2012CB967901)the National Nature Science Foundation of China(NSFC81400472)
文摘Mini pig models are large mammals and their ears are more similar with human beings in structure and development than other animals.However,the study on porcine ears is still in the initial stage and there is no description of an ideal operation approach to endocochlear potential and potassium ion concentration measurements.In this article,we describe a pre-auricular surgical approach to access the middle and inner ear for endocochlear potential and potassium ion concentration measures in mini pig models.Ten one-week old normal mini pigs were used in the study.The bulla of the temporal bone was accessed via a pre-auricular approach for endocochlear potential and potassium ion concentration measurements.The condition of the animals during the first post—experiment 24 h was observed.One animal died during surgery.The preauricular approach improved protection and preservation of relevant nervous and vascular elements including the facial nerve and carotid artery.So,the pre-auricular approach can be used for endocochlear potential and potassium ion concentration measurements with improved nerve and artery preservation mini pigs.
文摘To assess the relationship between cochlear blood flow (CBF) and auditory function, a procedure of intravital microscopy for observations of the lateral wall vessels of the cochlea coupled with the simultaneous measurement of the endocochlear potential (EP) was established in guinea pigs with gradual ischemia of the cochlea. It was found that occlusions of both common carotid arteries and one of the vertebral arteries produced a minor reduction in CBF with no significant alteration in the EP. When intravenous infusion of ATP induced sharp and severe decreases in CBF, the EP varied only slightly from the baseline in some animals while there were no alteration in others. Furthermore, ATP infusions combined with arterial occlusions caused even more severe declines in CBF and a moderate decrease in the EP. The results indicate that not only does the CBF satisfy the basic needs of the processes of cochlear function, but also has a regulatory mechanism to ensure the normal function of the cochlea in the ischemia condition. It was also found that the changes in the stria vascularis vessels induced by decreases in blood pressure (BP) and heart rates were more severe than those of the spiral ligament vessels. This phenomenon indicated that the stria vascularis vessels were more sensitive to decreases of BP and heart rates.
