Single Unit Recordings of Cells Responsive to Visual, Somatic, Acoustic, and Noxious Stimuli in the Superior Colliculus of the Golden Hamster.
Abstract
Responses of single neurons to sensory stimuli were studied in the superior colliculus of the golden hamster. A laminar organization was observed with cells in the superficial layers responding exclusively to visual stimuli, whereas the intermediate and deeper layers contained cells which responded to visual, somatic, acoustic, and multimodal inputs. Electrophysiological and pharmacological evidence is also presented which shows that cells of the lower laminae respond to nociceptive inputs. The internal organization of visual receptive fields was studied in both upper and lower laminar cells with parametric variation of stationary and moving stimuli. Generally, optimal stimuli had low velocities (< 50 deg/sec), were less than 50% of the receptive field diameter, and moved toward the upper nasal quadrant of visual space. Stimulus size and velocity were found to affect a cell's directional preference, which was a factor influencing the discharge frequency of 65% of the cells studied. A somatotopic map was apparent in the intermediate and deep layers of the superior colliculus. Receptive fields of the head and forelimbs were located rostrally in the superior colliculus and receptive fields of the hindquarters were located caudally. The somatic representation in the superior colliculus is in topographic register with the overlying visual representation. 'Nociceptive' cells which were activated by pinch, pin-prick, and heat were found in the intermediate and deep layers of the superior colliculus.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1978
- Accession Number
- ADA091548
Entities
People
- James Patrick Dixon
Organizations
- Air Force Institute of Technology