Contralateral head movements produced by microinjection of glutamate into superior colliculus of rats: Evidence for mediation by multiple output pathways

摘要: Abstract One of the major efferent pathways superior colliculus crosses midline to run caudally in contralateral predorsal bundle, innervating targets brain stem and eventually reaching cervical spinal cord. A variety evidence suggests that this tecto-reticulo-spinal pathway may mediate orienting movements can be evoked by tectal stimulation. However, we have recently found head still obtained rats after section pathway, implying additional are also involved. The present study sought test implication, taking advantage fact cells origin largely segregated within lateral part stratum album intermediate. It is thus possible find out whether produced a cell-excitant from regions contain few pathway. Hooded an open field were filmed during microinjections sodium l -glutamate (50 mM, 200 nl) into films analysed for appearance contralaterally directed body. Subsequent histological reconstruction injection sites indicated such could widespread areas colliculus, including not only intermediate but deep layers parts medial superficial layers. Moreover, or close often gave circling with downward pointing head, whereas some outside sustained immobility upwards. s supports view besides involved control movement. In addition, at least these collaterals since collicular cells. Finally, results consistent different output functions.