ISSN:
1432-1106
Keywords:
Cortico-geniculate influence
;
Lateral geniculate nucleus
;
Rat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Unitary discharges of the lateral geniculate nucleus (LGN) were analyzed in anesthetized and paralyzed rats after inactivation of visual cortical areas (VC) by cryoblockade or by depositing a cotton wick soaked in KCl (3 M). The receptive fields were mapped prior to and following the interruption of the cortico-geniculate feedback. The responsiveness of the VC was controlled by monitoring evoked potentials and the EEG. In most off-center and about half on-center cells the surround excitatory responses were markedly reduced and even totally abolished. In contrast, the center excitation remained unchanged or increased suggesting a parallel decline of the inhibitory surround. This differential influence of cortical blockade on on- or off-responses failed to appear in on-off cells whose receptive field was nonconcentrically organized. It is proposed that the VC exerts a complex influence upon geniculate physiology while the spatial center-surround relationships are under the control of the VC. The results of this investigation are comparable to those obtained in rabbits and cats.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00238152
