The Visual Cortex in Context

Abstract

In this article, we review the anatomical inputs and outputs to the mouse primary visual cortex, area V1. Our survey of data from the Allen Institute Mouse Connectivity project indicates that mouse V1 is highly interconnected with both cortical and subcortical brain areas. This pattern of innervation allows for computations that depend on the state of the animal and on behavioral goals, which contrasts with simple feedforward, hierarchical models of visual processing. Thus, to have an accurate description of the function of V1 during mouse behavior, its involvement with the rest of the brain circuitry has to be considered. Finally, it remains an open question whether the primary visual cortex of higher mammals displays the same degree of sensorimotor integration in the early visual system.

Characterization of Feedback Neurons in the High-Level Visual Cortical Areas That Project Directly to the Primary Visual Cortex in the Cat

“…This result suggests that information in the higher-order visual cortex may need to return to the V1 area for further strengthening or integration before proceeding to perceptual output. Our results may challenge the traditional feedforward hierarchical processing model (Silvanto, 2014(Silvanto, , 2015 and support the reverse hierarchy theory or interactive model proposing that recurrent connections between V1 and higher-order visual areas form functional circuits mediating aware and unaware visual perception (Johnson and Burkhalter, 1997;Juan and Walsh, 2003;Tong, 2003;Juan et al, 2004;Silvanto et al, 2005;Koivisto et al, 2010;Froudarakis et al, 2019).…”

“…Nevertheless, the neuronal substrate carrying top-down influence to the V1 area is poorly understood. Based on neural circuit tracing techniques, some authors have taken great efforts to examine the corticocortical projections between low-level and higher-order visual cortex in the primate (Anderson and Martin, 2009 ), cat (Han et al, 2008 ; Connolly et al, 2012 ), ferret (Cantone et al, 2005 ; Khalil and Levitt, 2014 ) and mouse (Johnson and Burkhalter, 1994 ; Gonchar and Burkhalter, 2003 ; Laramée and Boire, 2014 ; Froudarakis et al, 2019 ). Complex back-projected connections are reported among varied cortical areas, such as V2 and V1 (Budd, 1998 ; Anderson and Martin, 2009 ), V5/V4/V3 and V1/V2 (Johnson and Burkhalter, 1997 ; Barone et al, 2000 ; Rockland and Knutson, 2000 ; Lyon and Kaas, 2002 ; Anderson and Martin, 2006 ) as well as area17, 18, 19, 21, PMLS and 7 (Symonds and Rosenquist, 1984 ; Shipp and Grant, 1991 ; Norita et al, 1996 ; Batardiere et al, 1998 ; Cantone et al, 2005 ; Han et al, 2008 ; Sherk, 2010 ).…”

Input-independent homeostasis of developing thalamocortical activity

“…The patterns of this activity are both a target and effector of arousal state modulation (McCormick et al 2020). Multiple roles have been suggested for spontaneous activity: mediating attention, increasing signal-to-noise, resetting synaptic weights, and changing the functional connectivity of neurons (Harris and Thiele 2011; Froudarakis et al 2019; Tononi and Cirelli 2020). Thus, it is not surprising that the acquisition of normal background activity is a key developmental checkpoint (Pavlidis et al 2017).…”

Performance in even a simple perceptual task depends on mouse secondary visual areas

“…Imaging studies have identified as many as sixteen individual, retinotopically mapped areas ( Zhuang et al, 2017 ) with differing strengths of connectivity to V1. The most heavily studied secondary visual areas, which receive the largest proportions of projections from V1, are the lateral and medial output pathway areas: LM (lateromedial), AL (anterolateral), RL (retrolateral), and PM (posteriomedial) ( Froudarakis et al, 2019 ). While more than half of V1 projections target these four secondary visual areas ( Han et al, 2018 ), V1 also projects to a number of other brain areas including frontal cortex and basal ganglia ( Han et al, 2018; Khibnik et al, 2014 ), both of which are involved in decision-making and action selection.…”