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:6/14/2017)...  IBM (NYSE: IBM ) is introducing several innovative ... to developing collaboration between startups and global businesses, taking place ... the event, nine startups will showcase the solutions they have ... France is one ... a 30 percent increase in the number of startups created ...
(Date:5/6/2017)... 5, 2017 RAM Group , ... new breakthrough in biometric authentication based on a ... properties to perform biometric authentication. These new sensors are ... created by Ram Group and its partners. This sensor ... supply chains and security. Ram Group is a ...
(Date:4/17/2017)... 2017 NXT-ID, Inc. (NASDAQ: NXTD ) ... of its 2016 Annual Report on Form 10-K on Thursday April ... ... in the Investor Relations section of the Company,s website at ... at http://www.sec.gov . 2016 Year Highlights: ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... At its national board meeting ... I. Sheikh, the co-founder, CEO and chief research scientist of Minnesota-based Advanced Space ... membership in ARCS Alumni Hall of Fame . ASTER Labs is a ...
(Date:10/11/2017)... ... October 11, 2017 , ... ComplianceOnline’s Medical Device Summit is back for its ... 2018 in San Francisco, CA. The Summit brings together current and former FDA office ... directors and government officials from around the world to address key issues in device ...
(Date:10/11/2017)... LAGUNA HILLS, Calif. , Oct. 11, 2017  SkylineDx ... London (ICR) and University of Leeds ... to risk-stratify patients with multiple myeloma (MM), in a multi-centric ... The University of Leeds is the ... UK, and ICR will perform the testing services to include ...
(Date:10/11/2017)... , ... October 11, 2017 , ... ... (FDA) has granted orphan drug designation to SBT-100, its novel anti-STAT3 (Signal Transducer ... treatment of osteosarcoma. SBT-100 is able to cross the cell membrane and bind ...
Breaking Biology Technology:
Cached News: