Visual perception is mediated by complex interactions amongst neurons in the retina, visual cortex, and subcortical brain structures. The importance of vision to humans and other primates is reflected in the enormous percentage of cerebral cortex devoted to processing visual information. Thus, deficits in visual processing are particularly debilitating and arise from abnormalities not only in the eye, but also in cortical circuitry. For example, strabismus or amblyopia during childhood can have long-lasting effects on the cortical circuits that process visual information. There is also evidence that some forms of dyslexia result from central visual system abnormalities. The proposed studies are aimed at understanding the organization and function of neural circuits to, from, and within the primary visual cortex (V1), with the broader objective of understanding how neural circuits mediate visual perception. In particular, these studies aim to identify: 1) the detailed morphological properties of V1 cell types that project to particular extrastriate visual cortical areas and subcortical structures;2) the sources of direct local input to V1 neurons with projections to particular extrastriate visual cortical areas and subcortical structures;3) the retinal ganglion cell types that provide input, via the LGN, to functionally and anatomically distinct compartments in V1;and 4) how the in vivo visual response properties of individual, identified neurons correlate with the connectivity of these same cell types, as revealed by our previous and ongoing in vitro studies. The first 3 goals will be achieved using novel viral circuit tracing tools developed in the principal investigator's laboratory. These tools allow complete filling of identified projection neurons and monosynaptically-restricted transynaptic labeling from specific projection neurons. The last aim is accomplished by recording visual responses of V1 neurons and labeling them with dye to correlate anatomically distinct cell types with function. The proposed studies will allow an unprecedented view of visual cortical circuits - they will reveal the detailed connectivity of neurons in visual cortex and how these circuits relate to the functional properties of the component neurons. Lay summary: Deficits in visual processing are particularly debilitating and arise from abnormalities not only in the eye, but also in cortical circuitry. The proposed studies will reveal the normal organization and function of visual cortical circuits, which is necessary to understand the underlying causes of visual dysfunction.

National Institute of Health (NIH)
National Eye Institute (NEI)
Research Project (R01)
Project #
Application #
Study Section
Central Visual Processing Study Section (CVP)
Program Officer
Steinmetz, Michael A
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Salk Institute for Biological Studies
La Jolla
United States
Zip Code
Zarrinpar, Amir; Callaway, Edward M (2016) Functional Local Input to Layer 5 Pyramidal Neurons in the Rat Visual Cortex. Cereb Cortex 26:991-1003
Cetin, Ali; Callaway, Edward M (2014) Optical control of retrogradely infected neurons using drug-regulated ""TLoop"" lentiviral vectors. J Neurophysiol 111:2150-9
Nienborg, Hendrikje; Hasenstaub, Andrea; Nauhaus, Ian et al. (2013) Contrast dependence and differential contributions from somatostatin- and parvalbumin-expressing neurons to spatial integration in mouse V1. J Neurosci 33:11145-54
Nauhaus, Ian; Nielsen, Kristina J; Disney, Anita A et al. (2012) Orthogonal micro-organization of orientation and spatial frequency in primate primary visual cortex. Nat Neurosci 15:1683-90
Nielsen, Kristina J; Callaway, Edward M; Krauzlis, Richard J (2012) Viral vector-based reversible neuronal inactivation and behavioral manipulation in the macaque monkey. Front Syst Neurosci 6:48
Marshel, James H; Kaye, Alfred P; Nauhaus, Ian et al. (2012) Anterior-posterior direction opponency in the superficial mouse lateral geniculate nucleus. Neuron 76:713-20
Nauhaus, Ian; Nielsen, Kristina J; Callaway, Edward M (2012) Nonlinearity of two-photon Ca2+ imaging yields distorted measurements of tuning for V1 neuronal populations. J Neurophysiol 107:923-36
Nhan, Hoang L; Callaway, Edward M (2012) Morphology of superior colliculus- and middle temporal area-projecting neurons in primate primary visual cortex. J Comp Neurol 520:52-80
Callaway, Edward M; Borrell, VĂ­ctor (2011) Developmental sculpting of dendritic morphology of layer 4 neurons in visual cortex: influence of retinal input. J Neurosci 31:7456-70
Marshel, James H; Garrett, Marina E; Nauhaus, Ian et al. (2011) Functional specialization of seven mouse visual cortical areas. Neuron 72:1040-54

Showing the most recent 10 out of 52 publications