Vision Laboratory

Dr Protti’s laboratory is focused on the study of different neuronal circuits which are concerned with the analysis of singular aspects of the visual world. The first steps of visual processing take place in the retina. Visual signals conveyed from the retina to other areas of the brain contain information about contrast, colour, movement and direction of the movement among other features of the visual world. These attributes of visual stimuli are first segregated in the retina, each following a specific path, which utilise specific channels and neurotransmitter receptors to shape light signals. In the retina there are different neuronal networks devoted to signalling at low light levels (scotopic or rod circuit) whereas another network exclusively transmits signals at high light levels (photopic or cone circuit).

We are particularly interested in the changes that take place during the switch from night‑time to daytime vision. This transition is strongly influenced by the neurotransmitter dopamine, which acts as a light signal as well as other neuroactive substances. We are investigating the modulation of channels and receptors as well as the changes in synaptic transfer function by substances involved in the transition from night‑time to daytime vision.

We are also interested in the mechanisms involved in lateral inhibition, a phenomenon by which the retina sensitivity is adjusted to different light intensity levels conserving the ability to form high contrast images. To gain insight into this problem, we are also studying which neuronal networks generate the different components of the receptive fields of retinal ganglion cells and the interaction between neuronal and glial networks.

Our approach consists of recording light-responses of different cell types in an intact retinal preparation (whole-mount and/or slices) by using the patch‑clamp technique in combination with pharmacological manipulation. Additionally, cells are morphologically identified to help correlate them to their function.