[Neuronal coding of spatial visual information].
The main differences between the geniculate and the ascending tectal/extrageniculate visual systems are the presence of multisensory units and the absence of the strict retinotopical organization in the tectal system.


OBJECTIVE
To investigate the coding of the visual and multisensory information in the tectal system, and to clarify the direction of visual information flow between the extrastriate cortex along the anterior ectosylvian sulcus and the lateral medialis-suprageniculate nucleus of the posterior thalamus.


METHODS
Extracellular single-cell recordings were carried out in anesthetized, immobilized cats to visual and multisensory stimulation.


RESULTS
The thalamo-cortical route seems to have a dominant role in the bidirectional information flow between the LM-Sg and the AES cortex. The panoramic neurons in the AES cortex and the LM-Sg may code in their discharge rate the site of the spatial visual and multisensory information and exhibited multisensory cross-modal integration.


CONCLUSIONS
Our results demonstrate the existence of a distributed population code of spatial multisensory information in the tectal visual system.
Eördegh
Gabriella
G
Szegedi Tudományegyetem, Altalános Orvostudományi Kar, Elettani Intézet, Pszichiátriai Klinika, Szeged. eordegh@nepsy.szote.u-szeged.hu
D000704:Analysis of Variance; D000818:Animals; D002415:Cats; D009474:Neurons / Q000502:physiology*; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*