Updated Evidence Based Guideline on Acute Otitis Externa Released

The American Academy of Otolaryngology — Head and Neck Surgery Foundation released an updated evidence-based guideline to improve the diagnosis and treatment of Acute Otitis Externa (AOE) or swimmer's ear.

Acute Otitis Externa is an infection of the outer ear caused by bacteria multiplying in the ear canal due to trapped water. It is prevalent during summer and warm climates when increased ear exposure to water is at a high.

Aside from bacteria and water, swimmer's ear can also be caused by skin conditions that may contribute to debris in the ear canal, trauma from aggressive ear cleaning, trauma from wearing hearing aids, sweating, allergies, and stress.

Symptoms of acute otitis externa are inflammation, itching, a feeling of fullness with or without hearing loss, and pain when tugging on the earlobe or chewing food. Analgesics and eardrops are commonly used to treat the condition. These usually include antiseptics, antibiotics, and corticosteroids. The most effective treatment for AOE is eardrops because of the high local concentration of drug in the ear canal.

Oral medication is not as effective because of drug resistance and low concentration achieved in the ear canal compared to a topical method such as eardrops. Avoiding water accumulation and moisture retention in the external ear canal, and maintaining a healthy skin barrier can prevent AOE.

The guideline was released to promote the use of analgesics and topical treatments and discourage oral therapy which is deemed ineffective and has adverse effects. The update also includes new and updated clinical trials, systematic reviews, and the participation experts in various fields.

Developing More Efficient Hearing Aids Through OCH Transduction

Researchers are studying how the cochlea, located in the ear, processes and amplifies sound. This research could lead to better hearing aids.

Scientists have discovered that hearing relies on a mechanical traveling wave that is actively boosted by electromechanical forces in sensory outer hair cells (OHCs). By studying the process of OHC transduction, better devices that can send more accurate sound signals to brain can be developed.

Transduction is the conversion of a sensory stimulus (hearing, sight, taste, etc) to a sensory signal that the brain can process.

Just recently, scientists have also discovered a protein called TMHS that may be a critical component in converting soundwaves to electrical signals that the brain can process.

Scientists Discover Molecule Responsible For Converting Soundwaves To Brain Signals For Hearing

Scientists have identified a critical component responsible for converting soundwaves into electrical signals that the brain can process into sound. The discovery of this protein called TMHS may lead to a better understanding of the hearing process and lead to novel treatments for deafness.

The ear converts soundwaves into neurological impulses that the brain can process into the sounds that we hear.

When soundwaves enter the ear, the eardrum starts vibrating and passes these vibration into the middle ear and is amplified as it goes to the inner ear. These vibrations are then translated into electrical signals that brain synapses can pass on to the brain.

There is a distinct shift from a mechanical process from the vibration of the eardrum to an electrical process where the brain synapses transmit these vibrations as electrical impulses.

Although the process of hearing is basically understood, the way the ear converts the vibrations caused by the sound waves into electrical impulses is not. By identifying the specific chemical or protein that is responsible for this conversion process, it can open up medical possibilities in improving conditions and therapy for the deaf and hearing impaired.

Motor Skills Interactions Affect How Brain Hemispheres Process Different Kinds of Sounds

The human auditory system is responsible for the processing of sound. It is the system used for the sense of hearing. As sound is picked up by the ear, it is relayed to the primary auditory cortex which is a region of the brain that process sound and helps us to hear.

The brain has two hemispheres, the left hemisphere and the right hemisphere, which are responsible for specific motor, cognitive, and organ functions. Researchers at Georgetown University Medical Center say that both hemispheres of the brain are responsible for specific processing of sound.

"Language is processed mainly in the left hemisphere, and some have suggested that this is because the left hemisphere specializes in analyzing very rapidly changing sounds," says the study's senior investigator, Peter E. Turkeltaub, M.D., Ph.D., a neurologist in the Center for Brain Plasticity and Recovery.

Study Examines How Synapses Transmit Signals From The Ear To The Brain

This is a diagram of a typical central nervous system synapse. The presynaptic and postsynaptic neuron are on top and bottom. Mitochondria are light green, receptors dark green, postsynaptic density is in grey, Brown pyramids represent protein clusters composing the active zone, cell adhesion molecules are brown rectangles, synaptic vesicles are tan spheres, endoplasmic reticulum is the tan structure on the bottom left.

A synapse is a structure in the body's nervous system that permits a neuron to pass a signal (chemical or electrical) to another cell. A neuron is a cell that pass signals to individual cells.

Synapses are integral to the function of neurons. It is how neurons are able to communicate signals. There are two different kinds of synapses; a chemical synapse and an electrical synapse.

In a chemical synapse, the presynaptic neuron releases a chemical called a neurotransmitter that binds to receptors located in the postsynaptic cell, usually embedded in the plasma membrane. The neurotransmitter may initiate an electrical response or a secondary messenger pathway that may either excite or inhibit the postsynaptic neuron.

In an electrical synapse, the presynaptic and postsynaptic cell membranes are connected by special channels called gap junctions that are capable of passing electric current, causing voltage changes in the presynaptic cell to induce voltage changes in the postsynaptic cell. The main advantage of an electrical synapse is the rapid transfer of signals from one cell to the next.

Between the ear and brain, an orderly orchestra of synapses

The brain receives information from the ear in a surprisingly orderly fashion, according to a University at Buffalo study scheduled to appear June 6 in the Journal of Neuroscience.

The research focuses on a section of the brain called the cochlear nucleus, the first way-station in the brain for information coming from the ear. In particular, the study examined tiny biological structures called synapses that transmit signals from the auditory nerve to the cochlear nucleus.

The major finding: The synapses in question are not grouped randomly. Instead, like orchestra musicians sitting in their own sections, the synapses are bundled together by a key trait: plasticity.