The effects of monocular enucleation on visual topography in area 17 in the rabbit

1992 ◽  
Vol 91 (2) ◽  
Author(s):  
RobertJ. Clarke ◽  
BethW. Datskovsky ◽  
AntonyM. Grigonis ◽  
E.Hazel Murphy
Keyword(s):  
Area 17 ◽  
Monocular Enucleation ◽  
Visual Topography

Neonatal monocular enucleation and the geniculo-cortical system in the golden hamster: Shrinkage in dorsal lateral geniculate nucleus and area 17 and the effects on relay cell size and number

1995 ◽  
Vol 12 (5) ◽  
pp. 971-983 ◽  
Author(s):  
A.J. Trevelyan ◽  
I.D. Thompson
Keyword(s):  
Cell Size ◽  
Lateral Geniculate Nucleus ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Area 17 ◽  
Relay Cell ◽  
Monocular Enucleation ◽  
Lateral Geniculate ◽  
Retinal Input ◽  
Dorsal Lateral Geniculate ◽  
Relay Neurons

AbstractWe have examined the effects of neonatal monocular enucleation on the volume of the dorsal lateral geniculate nucleus (dLGN), the area of area 17, and the size and numbers of geniculate relay neurons identified by retrograde transport of HRP from cortex. Compared to values for normal animals, the only significant change contralateral to the remaining eye was an increase in relay cell radius. The effects ipsilateral to the remaining eye were more widespread: we found significant reductions in the volume of the dLGN (27% reduction), the area of striate cortex (22%), and the number (16%) and average soma radius (6%) of geniculate relay neurons. The relay neurons were also more densely packed, suggesting that other geniculate cell types were affected similarly, although this was not explicitly examined. These changes were not uniform throughout the nucleus, and as such, reflected the changes in retinal input. The greatest reduction in cell size occurred in the region of the ipsilateral dLGN receiving the most sparse retinal input subsequent to enucleation. Nor was the shrinkage of the dLGN uniform, being most apparent in the coronal plane especially along the axis orthogonal to the pia; there appeared to be little change in the anteroposterior extent. Shrinkage in area 17 ipsilateral to the remaining eye was the same (about 22%) whether it was defined by myelin staining or transneuronal transport of WGA-HRP. These results show that the transneuronal changes seen in the organization of visual cortex after early monocular enucleation in rodents are associated with only a moderate loss of geniculate relay cells.

Favored patterns in spike trains. II. Application

1983 ◽  
Vol 49 (6) ◽  
pp. 1349-1363 ◽  
Author(s):  
J. E. Dayhoff ◽  
G. L. Gerstein
Keyword(s):  
Striate Cortex ◽  
Biological Significance ◽  
Companion Paper ◽  
Spike Trains ◽  
Area 17 ◽  
Stimulus Information ◽  
Experimental Conditions ◽  
Cat Striate Cortex ◽  
Template Methods ◽  
Anesthetized Cat

In this paper we apply the two methods described in the companion paper (4) to experimentally recorded spike trains from two preparations, the crayfish claw and the cat striate cortex. Neurons in the crayfish claw control system produced favored patterns in 23 of 30 spike trains under a variety of experimental conditions. Favored patterns generally consisted of 3-7 spikes and were found to be in excess by both quantized and template methods. Spike trains from area 17 of the lightly anesthetized cat showed favored patterns in 16 of 27 cases (in quantized form). Some patterns were also found to be favored in template form; these were not as abundant in the cat data as in the crayfish data. Most firing of the cat neurons occurred at times near stimulation, and the observed patterns may represent stimulus information. Favored patterns generally contained up to 7 spikes. No obvious correlations between identified neurons or experimental conditions and the generation of favored patterns were apparent from these data in either preparation. This work adds to the existing evidence that pattern codes are available for use by the nervous system. The potential biological significance of pattern codes is discussed.

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