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:


(Date:6/27/2016)... 2016 Research and Markets has announced the ... report to their offering. The ... to grow at a CAGR of 12.28% during the period ... an in-depth market analysis with inputs from industry experts. The report ... years. The report also includes a discussion of the key vendors ...
(Date:6/22/2016)... -- The American College of Medical Genetics and Genomics was once ... one of the fastest-growing trade shows during the Fastest 50 ... Las Vegas . Winners ... each of the following categories: net square feet of paid ... The 2015 ACMG Annual Meeting was ranked 23 out of ...
(Date:6/22/2016)... , June 22, 2016   Acuant ... and verification solutions, has partnered with RightCrowd ... solutions for Visitor Management, Self-Service Kiosks and ... products that add functional enhancements to existing ... corporations and venues with an automated ID ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... Seattle, WA (PRWEB) , ... June 23, 2016 ... ... technology, announces the release of its second eBook, “Clinical Trials Patient Recruitment and ... patient recruitment and retention in this eBook by providing practical tips, tools, and ...
(Date:6/23/2016)... , June 23, 2016   Boston ... of novel compounds designed to target cancer stemness ... has been granted Orphan Drug Designation from the ... treatment of gastric cancer, including gastroesophageal junction (GEJ) ... inhibitor designed to inhibit cancer stemness pathways by ...
(Date:6/23/2016)... , June 23, 2016 A person commits ... the crime scene to track the criminal down. ... U.S. Food and Drug Administration (FDA) uses DNA evidence to ... Sound far-fetched? It,s not. The FDA has ... to support investigations of foodborne illnesses. Put as simply as ...
(Date:6/23/2016)... ... 23, 2016 , ... Charm Sciences, Inc. is pleased to ... AOAC Research Institute approval 061601. , “This is another AOAC-RI approval of the ... Vice President of Regulatory and Industrial Affairs. “The Peel Plate methods perform comparably ...
Breaking Biology Technology:
Cached News: