Efficacy of Hearing Aids in Patients with Hearing Difficulties in Noise: Focus on Hidden Hearing Loss.

Hearing aids (HAs) have been used for standard high-frequency hearing loss and tinnitus, but their effects on speech intelligibility in noise (SIN) in people with normal hearing, including hidden hearing loss (HHL), have been little explored. We included in a prospective cohort study patients who experience poor SIN and have normal pure tone average in quiet conditions or slight HL. We used open-fit HAs.

Evolution of rod bipolar cells and rod vision.

Bipolar cells are vertebrate retinal interneurons conveying signals from rod and cone photoreceptors to amacrine and ganglion cells. Bipolar cells are found in all vertebrates and have many structural and molecular affinities with photoreceptors; they probably appeared very early during vertebrate evolution in conjunction with rod and cone progenitors. There are two types of bipolar cells, responding to central illumination with depolarization (ON) or hyperpolarization (OFF).

Molecular characterization of the sea lamprey retina illuminates the evolutionary origin of retinal cell types.

The lamprey, a primitive jawless vertebrate whose ancestors diverged from all other vertebrates over 500 million years ago, offers a unique window into the ancient formation of the retina. Using single-cell RNA-sequencing, we characterize retinal cell types in the lamprey and compare them to those in mouse, chicken, and zebrafish. We find six cell classes and 74 distinct cell types, many shared with other vertebrate species.

RDH12 allows cone photoreceptors to regenerate opsin visual pigments from a chromophore precursor to escape competition with rods.

Capture of a photon by an opsin visual pigment isomerizes its 11-cis-retinaldehyde (11cRAL) chromophore to all-trans-retinaldehyde (atRAL), which subsequently dissociates. To restore light sensitivity, the unliganded apo-opsin combines with another 11cRAL to make a new visual pigment. Two enzyme pathways supply chromophore to photoreceptors.