ELSC Seminar Series

The mammalian retina is considered an autonomous neuronal tissue, yet there is evidence that it receives inputs from the brain in the form of retinopetal axons. We identified retinopetal axons that originate from histaminergic neurons located in the tuberomammillary nucleus (TMN) of the hypothalamus. Using Ca2+ imaging and electrophysiology, we revealed how histamine application, as well as a direct activation of the retinopetal axons, modulate activity of retinal neurons. We also found that an antihistamine alters visual sensitivity in humans. Since TMN activity was shown to correlate with arousal state, our data suggest that the retinal code changes with behavioral state through the release of histamine from TMN neurons.