Music to our ear requires alternative splicing

Music to our ear requires alternative splicing

The process of hearing is an extraordinary complex task. The ear has to translate the incoming sound - appearing in form of a wave - to a signal which the brain can “understand”. The organ which does the principal duty in mammals is the so called Organ of Corti. This organ is responsible for the identification of sounds in different frequencies. Along the length of the Organ of Corti are hair cells. Each of the hair cells responds strongly to one specific sound frequency. The hair cells form a gradient along the membrane of the organ of Corti, with cells at one end tuned to low frequencies and cells at the other end tuned to high sound frequencies.

Each of the hair cells has about 100 tiny hairs which are leaning on each other in their resting state. In response to pressure, which is caused by an incoming sound wave, they move. Under this physical stress the hairs generate electric signals which stimulate the auditory nerve which then sends electrical impulses to the brain.

Mechanical stimulation of hair cells caused by a sound wave makes the cells contract and expand which causes channels (called ion channels) to open and close. The frequency at which they open and close determines the sound frequency detected and different hair cells detect different sound frequencies because of variation in a protein at the ion channel – the variation is due to alternative splicing of this gene.

organ of Corti

The organ of Corti represents the connection of mechanical oscillations caused by an acoustic signal and the nervous signals within the cochlea. It was named after the Italian anatomist Marquis Alfonso Giacomo Gaspare Corti (1822-1876). This organ contains the sensory cells in the inner ear of mammalians. In human about 15.000 inner and outer hair cells can be found. The Organ of Corti contains between 15,000-20,000 auditory nerve receptors.