Campana Cell: a New Type of Neuron in the Retina

Article: Researchers Discover New Type of Nerve Cell in the Retina
Source: University of Utah Medicine
Published: October 28, 2021 

Scientists at Moran Eye Center at University of Utah have discovered a new type of neuron in the retina. Named the Campana cell for its bell-like shape, this interneuron possesses hybrid characteristics of both a bipolar cell and an amacrine cell, while also differing significantly from both the other types of interneurons. For example, like bipolar cells, Campana cells relay information from the photorceptors (in this case both rods and cones) to the retinal ganglion cells. Campana cells also share some features with amacrine cells, specifically Aii-ACs, such as neurite morphology in the inner plexiform layer, the expression of some AC-specific markers, and possibly the release of the inhibitory neurotransmitter glycine. However, this combination of characteristics also makes the Campana cell distinct. The lead researcher states, “Based on its morphology, physiology, and genetic properties, this cell doesn’t fit into the five classes of retinal neurons first identified more than 100 years ago. We propose they might belong to a new retinal neuron class by themselves.” Thus far, the scientists have discovered that Campana cells remain activated for an unusually long duration, as long as 30 seconds in response to a 10 millisecond light flash stimulus. The lead scientist speculates that this long duration of activation plays a role in encoding "memory," similar to persistently firing neurons in the brain. The researchers conclude, "[O]ur results open the possibility for an unconventional retinal cell class that plays unique roles in visual processing."

My rating of this study: ⭐⭐⭐⭐🌸

Young BK, Ramakrishnan C, Ganjawala T, et al. "An uncommon neuronal class conveys visual signals from rods and cones to retinal ganglion cells." PNAS.  118(44):e2104884118. 2 November 2021. https://doi.org/10.1073/pnas.2104884118