Postsynaptic responses of cat visual cortical neurons to stimulation of the lateral geniculate body

1977 ◽  
Vol 9 (1) ◽  
pp. 74-76
Author(s):  
V. M. Shaban
Keyword(s):  
Cortical Neurons ◽  
Lateral Geniculate Body ◽  
Lateral Geniculate ◽  
Visual Cortical ◽  
Stimulation Of

Excitatory amino acid receptor-mediated transmission in geniculocortical and intracortical pathways within visual cortex

1991 ◽  
Vol 66 (1) ◽  
pp. 293-306 ◽  
Author(s):  
L. J. Larson-Prior ◽  
P. S. Ulinski ◽  
N. T. Slater
Keyword(s):  
Visual Cortex ◽  
Amino Acid ◽  
Cortical Neurons ◽  
Excitatory Amino Acid ◽  
Nmda Antagonist ◽  
Receptor Subtypes ◽  
Excitatory Amino Acid Receptor ◽  
Visual Cortical ◽  
Stimulation Of

1. A preparation of turtle (Chrysemys picta and Pseudemys scripta) brain in which the integrity of the intracortical and geniculocortical pathways in visual cortex are maintained in vitro has been used to differentiate the excitatory amino acid (EAA) receptor subtypes involved in geniculocortical and intracortical synapses. 2. Stimulation of the geniculocortical fibers at subcortical loci produces monosynaptic excitatory postsynaptic potentials (EPSPs) in visual cortical neurons. These EPSPs are blocked by the broad-spectrum EAA receptor antagonist kynurenate (1-2 mM) and the non-N-methyl-D-aspartate (NMDA) antagonist 6, 7-dinitroquinoxaline-2,3-dione (DNQX, 10 microM), but not by the NMDA antagonist D,L-2-amino-5-phosphonovalerate (D,L-AP-5, 100 microM). These results indicate that the geniculocortical EPSP is mediated by EAAs that access principally, if not exclusively, EAA receptors of the non-NMDA subtypes. 3. Stimulation of intracortical fibers evokes compound EPSPs that could be resolved into three components differing in latency to peak. The component with the shortest latency was not affected by any of the EAA-receptor antagonists tested. The second component, of intermediate latency, was blocked by kyurenate and DNQX but not by D,L-AP-5. The component of longest latency was blocked by kynurenate and D,L-AP-5, but not by DNQX. These results indicate that the compound intracortical EPSP is comprised of three pharmacologically distinct components that are mediated by an unknown receptor, by quisqualate/kainate, and by NMDA receptors, respectively. 4. Repetitive stimulation of intracortical pathways at 0.33 Hz produces a dramatic potentiation of the late, D,L-AP-5-sensitive component of the intracortical EPSP. 5. These experiments lead to a hypothesis about the subtypes of EAA receptors that are accessed by the geniculocortical and intracortical pathways within visual cortex.

Visual cortex contribution to the organization of eye movements produced by local electrical stimulation of the cat lateral geniculate body

1987 ◽  
Vol 19 (2) ◽  
pp. 126-130
Author(s):  
V. Ya. Svetlova ◽  
N. F. Podvigin ◽  
F. N. Makarov ◽  
K. P. Fedorova ◽  
E. V. Evpyat'eva
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Eye Movements ◽  
Lateral Geniculate Body ◽  
Lateral Geniculate ◽  
Stimulation Of

A functional role of cholinergic innervation to neurons in the cat visual cortex

1987 ◽  
Vol 58 (4) ◽  
pp. 765-780 ◽  
Author(s):  
H. Sato ◽  
Y. Hata ◽  
H. Masui ◽  
T. Tsumoto
Keyword(s):  
Electrical Stimulation ◽  
Lateral Geniculate Nucleus ◽  
Cortical Neurons ◽  
Striate Cortex ◽  
Cholinergic Innervation ◽  
Neuron Activity ◽  
Visual Responses ◽  
Stimulus Movement ◽  
Lateral Geniculate ◽  
Stimulation Of

1. Effects of microionophoretic application of acetylcholine (ACh) and its antagonists on neuronal responses to visual stimuli and to electrical stimulation of the lateral geniculate nucleus were studied in the cat striate cortex. 2. Responses elicited visually and electrically were facilitated by ACh in 74% of the cells tested, whereas the responses were suppressed in 16%. These ACh effects were blocked by a muscarinic antagonist, atropine, but not by a nicotinic antagonist, hexamethonium, indicating that the ACh effects are mediated through muscarinic receptors. A single application of atropine suppressed visual responses of cells facilitated by ACh, whereas it enhanced those of cells inhibited by ACh, suggesting that endogenous ACh may tonically modulate visual responsivity of cortical neurons. 3. In most cells with the facilitatory ACh effect, responses with single spikes to the electrical stimulation became more consistent, often with double spikes, during the ACh application. The suppressive effects of ACh were noted most often in cells with a longer response latency to electrical stimulation of lateral geniculate nucleus. 4. In most of the facilitated cells the spontaneous activity remained null or very low during ACh application, in spite of marked enhancement of visual responses, suggesting that ACh may improve the signal-to-noise ratio (S/N) of cortical neuron activity. To confirm this suggestion, we calculated a S/S + N index by counting the total number of spikes in the responses (S) and that in peristimulus time histogram (S + N) and found that it was improved during the ACh application in about a half of the cells, whereas it became worse in about one-fifth. 5. In most of the facilitated cells, ACh enhanced visual responses not only to optimal but also to nonoptimal stimuli, resulting in no improvement or even worsening of the orientation selectivity. This was also the case in the selectivity of direction of stimulus movement. 6. The laminar location of the facilitated cells was biased toward layers V and VI of the cortex, although they also made up the majority in layers II + III and about half the tested cells in layers IVab and IVc. 7. In the light of recent understanding of cortical circuitry, these results suggest that the cholinergic innervation to cortical neurons may play a role in improvement of the S/N ratio of information processing in the striate cortex and in facilitation of sending processed informations to other visual centers.

CORTICAL INTRACELLULAR POTENTIALS IN RESPONSE TO STIMULATION OF LATERAL GENICULATE BODY

1960 ◽  
Vol 23 (6) ◽  
pp. 592-601 ◽  
Author(s):  
Choh-Luh Li ◽  
Armando Ortiz-Galvin ◽  
Shelley N. Chou ◽  
Saxton Y. Howard
Keyword(s):  
Lateral Geniculate Body ◽  
Intracellular Potentials ◽  
Lateral Geniculate ◽  
Stimulation Of
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