What are the superior and inferior colliculus?
The superior colliculus is a synaptic layered structure. It comprises the dorsal aspect of the midbrain, posterior to the periaqueductal gray and immediately superior to the inferior colliculus. The inferior and superior colliculi are known collectively as the corpora quadrigemina (Latin, quadruplet bodies).
What is the function of superior colliculi?
The superior colliculus (SC) is a midbrain area where visual, auditory and somatosensory information are integrated to initiate motor commands. The SC plays a central role in visual information processing in the mouse; it receives projections from 85% to 90% of the retinal ganglion cells (RGCs).
What does corticospinal tract control?
The corticospinal tract controls primary motor activity for the somatic motor system from the neck to the feet. It is the major spinal pathway involved in voluntary movements.
Where do Tectospinal tracts cross?
The tectospinal tract fibers cross to the opposite side in the dorsal tegmental decussation. They descend through the pons and medulla into the ventral funiculus of the spinal cord, close to the ventral median fissure.
What is brain stem called?
The brainstem is divided into three sections in humans: the midbrain (mesencephalon), the pons (metencephalon), and the medulla oblongata (myelencephalon).
What is the optic tectum?
The optic tectum (superior colliculus in mammals) is a highly conserved midbrain nucleus of vertebrates that typically receives retinal input and directs the eyes and body toward salient visual features.
What kind of input does the superior colliculus receive?
The superior colliculus receives substantial input from the ipsilateral primary visual cortex (Stein and Meredith, 1991). In the deeper layers of the superior colliculus, many cells respond to somatosensory and auditory stimuli as well as visual input.
Where is the inferior colliculus located in the body?
The anatomic structure that includes inferior colliculi and the superior coliculi forms two parts: (1) the eminences of the corpora quadrigemina. (2) part of the tectal region of the midbrain. The inferior colliculus is located near the following structures: (1) the superior colliculus. (2) the trochlear nerve.
How does the superior colliculus contribute to ventriloquist effect?
The superior colliculus also receives auditory information from the inferior colliculus. This auditory information is integrated with the visual information already present to produce the ventriloquist effect.
Where does sound synapse with the inferior colliculus?
The inferior colliculus is the first place where vertically orienting data from the fusiform cells in the dorsal cochlear nucleus can finally synapse with horizontally orienting data. Sound location data thus becomes fully integrated by the inferior colliculus.