Biophysical network modeling of the dLGN circuit: Effects of cortical feedback on spatial response properties of relay cells
Metadatos
Mostrar el registro completo del ítemAutor
Martínez-Cañada, Pablo; Mobarhan, Milad Hobbi; Halnes, Geir; Fyhn, Marianne; Morillas Gutiérrez, Christian Agustín; Pelayo Valle, Francisco José; Einevoll, Gaute T.Editorial
Plos One
Fecha
2018-01-29Referencia bibliográfica
Martínez-Cañada P, Mobarhan MH, Halnes G, Fyhn M, Morillas C, Pelayo F, et al. (2018) Biophysical network modeling of the dLGN circuit: Effects of cortical feedback on spatial response properties of relay cells. PLoS Comput Biol 14(1): e1005930. https://doi.org/10.1371/journal.pcbi.1005930
Patrocinador
Human Brain Project (FET project 604102); Research Council of Norway (BIOTEK2021 Digital Life project `DigiBrain', project 248828); PhD scholarship FPU13/01487 and the research stay grant EST15/00055, both awarded by the Government of Spain, FPU programResumen
Despite half-a-century of research since the seminal work of Hubel and Wiesel, the role of
the dorsal lateral geniculate nucleus (dLGN) in shaping the visual signals is not properly
understood. Placed on route from retina to primary visual cortex in the early visual pathway,
a striking feature of the dLGN circuit is that both the relay cells (RCs) and interneurons (INs)
not only receive feedforward input from retinal ganglion cells, but also a prominent feedback
from cells in layer 6 of visual cortex. This feedback has been proposed to affect synchronicity
and other temporal properties of the RC firing. It has also been seen to affect spatial
properties such as the center-surround antagonism of thalamic receptive fields, i.e., the suppression
of the response to very large stimuli compared to smaller, more optimal stimuli.
Here we explore the spatial effects of cortical feedback on the RC response by means of a a
comprehensive network model with biophysically detailed, single-compartment and multicompartment
neuron models of RCs, INs and a population of orientation-selective layer 6
simple cells, consisting of pyramidal cells (PY). We have considered two different arrangements
of synaptic feedback from the ON and OFF zones in the visual cortex to the dLGN:
phase-reversed (`push-pull') and phase-matched (`push-push'), as well as different spatial
extents of the corticothalamic projection pattern. Our simulation results support that a
phase-reversed arrangement provides a more effective way for cortical feedback to provide
the increased center-surround antagonism seen in experiments both for flashing spots and,
even more prominently, for patch gratings. This implies that ON-center RCs receive direct
excitation from OFF-dominated cortical cells and indirect inhibitory feedback from ON-dominated
cortical cells. The increased center-surround antagonism in the model is accompanied
by spatial focusing, i.e., the maximum RC response occurs for smaller stimuli when
feedback is present.