HOME >> BIOLOGY >> NEWS
Ears can't hear when special sensory cells don't stay 'quiet'

und this was not the case in the inner ear, where the loss of Ink4d alone in mice lead to failed attempts at cell division and, ultimately, progressive death of sensory hair cells.

The researchers studied mice that lacked both copies of Ink4d (Ink4d -/- mice; normally, one copy of each gene is inherited from each parent). Using biochemical techniques that highlighted hair cells under the microscope, they observed hair cell loss in mice that were 2.5 weeks old. When the Ink4d -/- mice were seven weeks old, hair cell loss had progressed even further. Specifically, the innermost of four rows of sensory hair cells suffered a loss of 43.3% of cells, and the three outer rows suffered losses of 27.8%, 8.1%, and 8.5%, respectively. Mice that had both copies of the Ink4d gene (Ink4d +/+) did not suffer loss of sensory hair cells in the organ of Corti.

The researchers also used sound measurements to test how well the mice responded to sound. One test, called "distortion product otoacoustic emission" (DPOAE) measures sounds generated by the hair cells themselves in response to being stimulated by sound waves coming into the inner ear. The DPOAE test was performed at weeks 7 and 15 in both Ink4d +/+ and Ink4d -/- mice. The ears of normal mice produced normal responses to sound waves entering the ear, but the ears of mice lacking Ink4d did not respond to this stimulation.

In addition, the investigators used a test called "auditory brainstem response" (ABR) to compare the nerve response to sound in mice with and without Ink4d. The ABR test studies the electric impulses of the auditory nerve pathways from the ear in response to clicks or short bursts of sound. Specifically, it measures the so-called "sound pressure level (SPL)," or the strength a stimulus must be before there is a measurable response in these nerves. At 7 weeks of age the Ink4d -/- mice had responses similar to Ink4d +/+ mice. However, by week 15, the sound level had to be increased signi
'"/>

Contact: Bonnie Cameron
bonnie.cameron@stjude.org
901-495-4815
St. Jude Children's Research Hospital
1-May-2003


Page: 1 2 3 4

Related biology news :

1. Assisted reproduction cant compensate for waiting too long to start a family
2. When blood cant get to brain, special CT scan helps
3. Mutant biological machine makes proteins but cant let go
4. Marine reserves cant do it all: Sea otters vs. red abalone
5. Bacteria cant do their thing if they dont have cling
6. Targeting enzymes that immortalize cancer cells: if you cant turn them off, round them up
7. The bodys production of melatonin may be the reason why the elderly cant get a good nights sleep
8. Why some people just cant seem to pay attention
9. Researchers find clues about how antibodies specialize
10. Reading hexametric rhyme supports cardiac synchronization, especially after a heart attack
11. Bigger isnt always better--especially if youre a rodent

Post Your Comments:
*Name:
*Comment:
*Email:
TAG: Ears can hear when special sensory cells don stay quiet

(Date:10/29/2014)... Genomics of the Kidney consortium ( CAGEKID ) ... exposure to aristolochic acid, an ingredient in some ... Communications , have important implications for public health. ... every year, and in Central Europe incidence rates ... International Cancer Genome Consortium (ICGC), has been studying ...
(Date:10/28/2014)... and China have published a paper in the ... reveals important details about key transitions in the evolution ... exotic algae, mosses, ferns, trees and flowers growing deep ... eat and the ornamental plants adorning our homes, all ... of history., "Our study generated DNA sequences from a ...
(Date:10/28/2014)... be building a hybrid micro-grid which will integrate ... in the region, the hybrid micro-grid will test ... diesel, storage and power-to-gas technologies, and ensure these ... built under the new Renewable Energy Integration Demonstrator- ... located offshore at Semakau Landfill and is expected ...
Breaking Biology News(10 mins):Kidney cancer in Central Europe 2New study uses DNA sequences to look back in time at key events in plant evolution 2New study uses DNA sequences to look back in time at key events in plant evolution 3NTU to build region's first renewable energy integration demonstration micro-grid 2NTU to build region's first renewable energy integration demonstration micro-grid 3
(Date:10/30/2014)... Avure Technologies celebrates a year of success and the ... fleet of high volume High Pressure Processing (HPP) systems. , ... to PackExpo this year, which is where we first announced ... Williams, CEO at Avure. “Sales of the new Avure machine ... the challenges of market demand for higher throughput. We sold ...
(Date:10/30/2014)... solution to one of the key challenges in the ... of Sussex physicists. , In a paper published today ... Garraway and colleagues show how to make a new ... Quantum technology devices, such as high-precision sensors and specialised ... of atoms. But the methods for trapping these tiny ...
(Date:10/27/2014)... TORONTO , Oct. 27, 2014 /PRNewswire/ ... GNBT) today announced two presentations demonstrating that the ... novel proprietary cancer immunotherapeutic AE37 vaccine correlated with ... The AE37 cancer vaccine is being developed by ... www.antigenexpress.com ). The presentations are being made at ...
(Date:10/27/2014)... October 27, 2014 The report ... Intelligent Traffic Management, Communication, Monitoring), and by Display ... to 2019” segments the global market into various ... It also identifies the drivers and restraints for ... challenges. , Browse 75 market tables and 37 ...
Breaking Biology Technology:In High Demand: New High Pressure Processing (HPP) System with Maximum Throughput Drives Strong Sales 2In High Demand: New High Pressure Processing (HPP) System with Maximum Throughput Drives Strong Sales 3Generex Announces Presentations Correlating Immunological Response with Reduced Recurrence in Phase II Study of AE37 Breast Cancer Vaccine in Patients at the American College of Surgeons 2Generex Announces Presentations Correlating Immunological Response with Reduced Recurrence in Phase II Study of AE37 Breast Cancer Vaccine in Patients at the American College of Surgeons 3Generex Announces Presentations Correlating Immunological Response with Reduced Recurrence in Phase II Study of AE37 Breast Cancer Vaccine in Patients at the American College of Surgeons 4Smart Highway Market by Technology, and Display Expected to Reach $27.992.0 Million by 2019- New Report by MarketsandMarkets 2Smart Highway Market by Technology, and Display Expected to Reach $27.992.0 Million by 2019- New Report by MarketsandMarkets 3Smart Highway Market by Technology, and Display Expected to Reach $27.992.0 Million by 2019- New Report by MarketsandMarkets 4
Cached News: