analysis tools on mouse superior colliculus have revealed several important functions. In a series of studies, researchers have identified a set of Ying-Yang circuit modules in the superior colliculus to initiate prey capture and predator avoidance behaviors in mice. By using single-cell RNA-sequencing, researchers have analyzed the gene expression profiles of superior colliculus neurons and identified the unique genetic markers of these circuit modules. Other vertebrates Optic tectum The optic tectum is the visual center in the non-mammalian brain which develops from the alar plate of the mesencephalon. In these other vertebrates the connections from the optic tectum are important for the recognition and reaction to various sized objects which is facilitated by excitatory optic nerve transmitters like L-glutamate. Disrupting visual experience early on in zebrafish development results in a change in tectal activity. Changes in tectal activity resulted in an inability to successfully hunt and capture prey. Hypothalamus inhibitory signaling to the deep tectal neuropil is important in tectal processing in zebrafish larvae. The tectal neuropil contains structures including periventricular neuronal axons and dendrites. The neuropil also contains GABAergic superficial inhibitory neurons located in stratum opticum. Instead of a large cerebral cortex, zebrafish have a relatively large optic tectum that is hypothesized to carry out some of the visual processing that the cortex performs in mammals. Recent lesion studies have suggested that the optic tectum has no influence over higher-order motion responses like the optomotor response or the optokinetic response, but may be more integral to lower-order cues in motion perception like in the identification of small objects. The optic tectum is one of the fundamental components of the vertebrate brain, existing across a range of species. Some aspects of the structure are very consistent, including a structure composed of a number of layers, with a dense input from the optic tracts to the superficial layers and another strong input conveying somatosensory input to deeper layers. Other aspects are highly variable, such as the total number of layers (from 3 in the African lungfish to 15 in the goldfish), and the number of different types of cells (from 2 in the lungfish to 27 in the house sparrow). The optic tectum is closely associated with an adjoining structure called the nucleus isthmi, which has drawn a lot of interest because it evidently makes a very important contribution to tectal function. (In the superior colliculus the like structure is termed