ISSN:
1432-1106
Keywords:
Visual system
;
Pigeon
;
Thalamus
;
Evoked potential
;
Cryogenic blockade
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary In 4 dorsolateral thalamic nuclei (LA, DLAmc, DLLd and DLLv) short latency evoked responses were recorded after electrical or photic stimulation of the contralateral eye. Electrical stimulation of these 4 nuclei led to bilaterally evoked responses in the wulst, where previous experiments had demonstrated an oligosynaptic projection from the retina. Cooling in DLL, while stimulating the contralateral optic nerve, leads to a severe decrement of both wulst responses suggesting that the thalamus functions as a relay within the retino-thalamo-hyperstriatal pathway. When the optic nerve ipsilateral to the cooled thalamus is stimulated the ipsilateral wulst response is unchanged while the contralateral wulst response is enhanced, suggesting a disinhibition. Similarly an inhibitory effect of the thalamus on one side upon the contralateral wulst response was found after concomitant stimulation of one optic nerve and a delayed stimulation of the ipsilateral thalamus. The dorsolateral thalamic group is the origin of bilateral wulst projections, the pathway to the contralateral telencephalon was demonstrated to pass via the supraoptic decussation DSO. Cooling DSO diminished the inhibitory thalamic effect upon the contralateral wulst. DSO was corroborated as part of the ipsilateral retino-wulst system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00235744
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