Development and function of the pineal gland, a simplified retina.

Specification and function of a diversity of photoreceptors in a diurnal vertebrate

Photoreceptors are sensory cells responsible for sensing light. In vertebrates, most of the photoreceptors are found in the eye. However, there are some photoreceptors populations located within the brain. In particular, the zebrafish pineal gland contains a surprising diversity of photoreceptors which enable detection of different wavelengths and intensities by this organ. We are addressing how this diversity is generated during development.

One of the main functions of the pineal gland is melatonin production. This hormone, which functions as a ‘chemical expression of darkness’ is directly secreted by photoreceptors and is involved in the control of sleep. Another aspect of our activities is to understand how this diversity of photoreceptors control sleep either through melatonin production and/or through projection on specific neuronal targets.