Distribution and synaptic organization of serotoninergic and noradrenergic axons in the lateral geniculate nucleus of the rat

1990 ◽  
Vol 294 (3) ◽  
pp. 345-355 ◽  
Author(s):  
Georgios C. Papadopoulos ◽  
John G. Parnavelas
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Synaptic Organization ◽  
Lateral Geniculate

A quantitative electron-microscopical study of the postnatal development of the lateral geniculate nucleus in normal kittens and in kittens with eyelid suture

1980 ◽  
Vol 210 (1179) ◽  
pp. 211-234 ◽  
Keyword(s):  
Electron Microscope ◽  
Postnatal Development ◽  
Lateral Geniculate Nucleus ◽  
Normal Development ◽  
Microscopical Study ◽  
Electron Microscopical Study ◽  
Synaptic Organization ◽  
Eyelid Closure ◽  
Lateral Geniculate ◽  
Electron Microscopical

The postnatal development of the lateral geniculate nucleus has been studied quantitatively with the electron microscope in normal kittens and in kittens with eyelid closure. The maturation of the synaptic organization of glomeruli in the normal kitten occurs during the period of susceptibility to eyelid closure and is due predominantly to a logarithmic increase in the number of symmetric presynaptic dendritic synapses. In contrast, the pro­portion of symmetric synapses falls with age in non-glomerular neuropil over this period. Unilateral and bilateral eyelid suture do not interfere with the normal development of the lateral geniculate nucleus.

How much feedback from visual cortex to lateral geniculate nucleus in cat: A perspective

2004 ◽  
Vol 21 (4) ◽  
pp. 487-500 ◽  
Author(s):  
JULIAN M.L. BUDD
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Sensory Information ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Synaptic Organization ◽  
Lateral Geniculate ◽  
Order Of Magnitude ◽  
Efferent Neurons ◽  
Cortical Synapses ◽  
Corticothalamic Feedback ◽  
Dorsal Lateral Geniculate

Corticothalamic feedback is believed to play an important role in selectively regulating the flow of sensory information from thalamus to cortex. But despite its importance, the size and nature of corticothalamic pathway connectivity is not fully understood. In light of recent empirical data, the aim of this paper was to quantify the contribution of area 17 axon connectivity to the synaptic organization of A-laminae in dorsal lateral geniculate nucleus (dLGN) in cat, the best studied corticothalamic pathway. Numerical constraints indicate that most corticogeniculate synapses are not formed with inhibitory interneurons. However, the main finding is that there was an order of magnitude difference between estimates of the mean number of cortical synapses per A-laminae neuron based on individual corticogeniculate axon data (12,000–16,000 cortical synapses per cell) than that previously derived from partial reconstructions of the synaptic input to two physiologically identified relay cells (1200–1500 cortical synapses per cell). In an attempt to reconcile these different estimates, parameter variation and comparative analyses suggest that previous work may have overestimated the density of corticogeniculate efferent neurons and underestimated the total number of synapses per geniculate neuron. But as this analysis did not include area 18 corticogeniculate axons innervating A-laminae, the discrepancy between different estimates may be greater and require further explanation. Thus, the analysis presented here suggests geniculate neurons receive on average a greater number of cortical synapses per cell but from far fewer corticogeniculate axons than previously thought.

An electron-microscopical study of the postnatal development of the lateral geniculate nucleus in the normal kitten and after eyelid suture

1980 ◽  
Vol 210 (1179) ◽  
pp. 197-210 ◽  
Keyword(s):  
Endoplasmic Reticulum ◽  
Postnatal Development ◽  
Lateral Geniculate Nucleus ◽  
Normal Development ◽  
Microscopical Study ◽  
Synaptic Organization ◽  
Eyelid Closure ◽  
Lateral Geniculate ◽  
Adult Cat ◽  
Electron Microscopical

The postnatal development of the lateral geniculate nucleus has been studied qualitatively with the electron microscope in normal kittens and in kittens with unilateral or bilateral eyelid closure. From birth to about 20 days there is relatively little development and the ultrastructural features characteristic of the adult cat, especially the synaptic organization of glomeruli, are mainly acquired between 40 and 55 days, when there is a rapid increase in the level of maturity. Unilateral and bilateral eyelid suture have virtually no effect upon the normal development, but some neurons in the deprived laminae have slightly less granular endoplasmic reticulum.

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