Frequency dependent corticofugal excitation of principal cells in the cat's dorsal lateral geniculate nucleus

1990 ◽  
Vol 79 (2) ◽  
pp. 313-318 ◽  
Author(s):  
S. Lindstr�m ◽  
A. Wr�bel
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Frequency Dependent ◽  
Principal Cells ◽  
Lateral Geniculate ◽  
Dorsal Lateral Geniculate

Unitary EPSCs of Corticogeniculate Fibers in the Rat Dorsal Lateral Geniculate Nucleus In Vitro

2003 ◽  
Vol 89 (6) ◽  
pp. 2952-2960 ◽  
Author(s):  
Björn Granseth ◽  
Sivert Lindström
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Feedback System ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Size Distributions ◽  
Principal Cells ◽  
Quantal Size ◽  
Lateral Geniculate ◽  
Whole Cell Patch Clamp ◽  
Dorsal Lateral Geniculate

To investigate unitary corticogeniculate excitatory postsynaptic currents (EPSCs), whole cell patch-clamp recordings were obtained from 20 principal cells in slices of the dorsal lateral geniculate nucleus (dLGN) of DA-HAN rats. EPSCs, evoked by electrical stimulation of corticogeniculate axons, had size distributions with one or more quantal peaks. Gaussian curves fitted to such distributions gave a mean quantal size ( q) of -5.0 ± 0.7 (SD) pA for the EPSCs. Paired-pulse ratio (EPSC2/EPSC1) was 3.3 ± 0.9 for stimuli separated by 40 ms. The mean quantal size was similar for facilitated EPSCs (-5.2 ± 0.8 pA), implying an increase in mean quantal content ( m). Most corticogeniculate axons were capable of releasing only one or two quanta onto individual principal cells. Mean resting release probability ( p) was low, 0.09 ± 0.04. Binomial models, with the same n but increased p, could account for both the basal and facilitated EPSC size distributions in 6/8 cells. It is suggested that the low resting efficacy of corticogeniculate synapses serves to stabilize this excitatory feedback system. The pronounced facilitation in conjunction with large convergence from many corticogeniculate cells would provide a transient, potent excitation of dLGN cells, compliant with the idea of a visually driven neuronal amplifier.

scholarly journals Synaptic properties of the feedback connections from the thalamic reticular nucleus to the dorsal lateral geniculate nucleus

2020 ◽  
Vol 124 (2) ◽  
pp. 404-417 ◽  
Author(s):  
Peter W. Campbell ◽  
Gubbi Govindaiah ◽  
Sean P. Masterson ◽  
Martha E. Bickford ◽  
William Guido
Keyword(s):  
Lateral Geniculate Nucleus ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Thalamic Reticular Nucleus ◽  
Reticular Nucleus ◽  
Lateral Geniculate ◽  
Dependent Form ◽  
Dorsal Lateral Geniculate ◽  
Feedback Connections ◽  
Spike Firing ◽  
Stimulation Of

The thalamic reticular nucleus (TRN) modulates thalamocortical transmission through inhibition. In mouse, TRN terminals in the dorsal lateral geniculate nucleus (dLGN) form synapses with relay neurons but not interneurons. Stimulation of TRN terminals in dLGN leads to a frequency-dependent form of inhibition, with higher rates of stimulation leading to a greater suppression of spike firing. Thus, TRN inhibition appears more dynamic than previously recognized, having a graded rather than an all-or-none impact on thalamocortical transmission.

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