The layout of areas in the cerebral cortex different primates is quite similar, despite significant variations brain size. However, it clear that larger brains are not simply scaled up versions smaller brains: some regions disproportionately large species. It currently debated whether these expanded arise through natural selection pressures for increased cognitive capacity or as a result application common developmental sequence on scales. Here, we used computational methods to map and...

The marmoset is an emerging animal model for large‐scale attempts to understand primate brain connectivity, but achieving this aim requires the development and validation of procedures normalization integration results from many neuroanatomical experiments. Here we describe a computational pipeline coregistration retrograde tracing data on connections cortical areas into 3D template, generated Nissl‐stained sections. procedure in series spatial transformations that are applied coordinates...

The dorsomedial area (DM), a subdivision of extrastriate cortex characterized by heavy myelination and relative emphasis on peripheral vision, remains the least understood main targets striate (V1) projections in primates. Here we placed retrograde tracer injections encompassing full extent this marmoset monkeys, performed quantitative analyses numerical strengths laminar patterns its afferent connections. We found that feedforward from V1 second visual (V2) account for over half inputs to...

We used fluorescent tracers to map the pattern of cortical afferents frontal area 10 in marmosets. Dense projections originated several subdivisions orbitofrontal cortex, medial cortex (particularly areas 14 and 32), dorsolateral 8Ad 9). Major also stemmed, variable proportions depending on location injection site, from both inferior superior temporal sensory association areas, suggesting a degree audiovisual convergence. Other included polysensory pole, parabelt auditory cortex. Medial...

Contemporary studies recognize 3 distinct cytoarchitectural and functional areas within the Brodmann area 8 complex, in caudal prefrontal cortex: 8b, 8aD, 8aV. Here, we report on quantitative characteristics of cortical projections to these areas, using injections fluorescent tracers marmoset monkeys. Area 8b was from both 8aD 8aV due its connections with medial prefrontal, anterior cingulate, superior temporal polysensory, ventral midline/retrosplenial areas. In contrast, received bulk...

Abstract In light of anatomical evidence suggesting differential connection patterns in central vs. peripheral representations cortical areas, we investigated the extent to which response properties cells primary visual area (V1) marmoset change as a function eccentricity. Responses combinations spatial and temporal frequencies stimuli were quantified for neurons with receptive fields ranging from 3° 70° Optimal stimulus speeds reflected expectation that responses throughout V1 are...

Abstract The primary visual area (V1) forms a systematic map of the field, in which adjacent cell clusters represent points space. A precise quantification this is key to understanding anatomical relationships between neurons located different stations pathway, as well neural bases performance regions field. We used computational methods quantify topography V1 marmoset ( Callithrix jacchus ), small diurnal monkey. receptive fields throughout were mapped two anesthetized animals using...

Each visual experience changes the neural response to subsequent stimuli. If brain is unable incorporate these encoding changes, decoding, or perception, of stimuli biased. Although phenomenon adaptation pervades nervous system, its effects have been studied mainly in isolation, based on neuronal induced by an isolated, prolonged stimulus. To understand how adaptation-induced biases arise and persist under continuous, naturalistic stimulation, we simultaneously recorded responses up 61...

ABSTRACT We studied the afferent connections of two cytoarchitectural subdivisions caudolateral frontal cortex, areas 6Va and 8C, in marmoset monkeys. These received from same set thalamic nuclei, including main inputs ventral lateral anterior complexes, but differed their patterns corticocortical connections. Areas 8C had reciprocal interconnections, similar proportions afferents premotor 6M 6DC, prefrontal cortex. However, area stronger that have been implicated oculomotor functions,...

To evaluate the accuracy at which visual field global indices could be estimated from OCT scans of retina using deep neural networks and to quantify contributions estimates by macula (MAC) optic nerve head (ONH). Observational cohort study. A total 10 370 eyes 109 healthy patients, 697 glaucoma suspects, 872 patients with over multiple visits (median = 3). Three-dimensional convolutional were trained estimate derived automated Humphrey perimetry (SITA 24-2) tests (Zeiss, Dublin, CA),...

Lesions of striate cortex [primary visual (V1)] in adult primates result blindness. In contrast, V1 lesions neonates typically allow much greater preservation vision, including, many human patients, conscious perception. It is presently unknown how this marked functional difference related to physiological changes cortical areas that are spared by the lesions. Here we report a study middle temporal area (MT) marmoset monkeys received unilateral within 6 weeks birth. contrast with...

Lesions of striate cortex (V1) trigger massive retrograde degeneration neurons in the LGN. In primates, these lesions also lead to scotomas, within which conscious vision is abolished. Mediation residual visual capacity regions (blindsight) has been traditionally attributed an indirect pathway extrastriate cortex, involves superior colliculus and pulvinar complex. However, recent studies have suggested that preservation LGN critical for behavioral evidence blindsight, raising question what...

Abstract Although the primary visual cortex (V1) is one of most extensively studied areas primate brain, very little known about how far periphery space represented in this area. We characterized physiological response properties V1 neurons anaesthetized marmoset monkeys, using high-contrast drifting gratings. Comparisons were made between cells with receptive fields located three regions V1, defined by eccentricity: central (3–5°), near peripheral (5–15°), and (>50°). found that...

Modern neurophysiological and psychophysical studies of vision are typically based on computer-generated stimuli presented flat screens. While this approach allows precise delivery stimuli, it suffers from a fundamental limitation in terms the maximum achievable spatial coverage. This constraint becomes important that require stimulation large expanses visual field, such as those involving mapping receptive fields throughout extent cortical area or subcortical nucleus, comparing neural...

Adjacent neurons in visual cortex have overlapping receptive fields within and across area boundaries, an arrangement theorized to minimize wiring cost. This constraint is traditionally thought create retinotopic maps of opposing field signs (mirror nonmirror representations) adjacent areas, a concept that has become central current attempts subdivide the extrastriate cortex. We simulated formation using model balances constraints imposed by smoothness representation congruence between...

The marmoset monkey (Callithrix jacchus) has gained attention in neurophysiology research as a new primate model for visual processing and behavior. In particular, marmosets have lissencephalic cortex, making multielectrode, optogenetic, calcium-imaging techniques more accessible than other models. However, the degree of homology brain circuits behavior with those identified macaques humans is still being ascertained. For example, whereas location frontal eye fields (FEF) within dorsolateral...

Sensory perception depends on neuronal populations creating an accurate representation of the external world. The amount information that a population can represent tuning individual neurons and trial-by-trial variability shared among neurons. Although average, pairwise spike-count correlations between are positive, distribution is wide, relationship encoding not straightforward. Here, we examine how single-neuron population-level factors impact efficacy neural code. We recorded responses to...

The middle temporal (MT) area of the extrastriate visual cortex has long been studied in adulthood for its distinctive physiological properties and function as a part dorsal stream, yet interestingly it possesses similar maturation profile primary (V1). Here, we examined whether an early-life lesion MT marmoset monkeys (six female, two male) altered stream development behavioral precision reaching-to-grasp sequences. We observed permanent changes anatomy cortices associated with both...

Despite the importance of transition metals for normal brain function, relatively little is known about distribution these elemental species across different tissue compartments primate brain. In this study, we employed laser ablation-inductively coupled plasma-mass spectrometry on PFA-fixed sections obtained from two adult common marmosets. Concurrent cytoarchitectonic, myeloarchitectonic, and chemoarchitectonic measurements allowed identification major neocortical, archaecortical,...

The boundaries of the visual areas located anterior to V2 in dorsomedial region macaque cortex remain contentious. This is usually conceptualized as including two functional subdivisions: dorsal component area V3 (V3d) laterally and another named parietooccipital (PO) or V6 medially. However, nature putative border between V3d PO/V6 has remained undefined. We recorded receptive fields multiunit clusters male macaques reconstructed locations recording sites using histological sections...

Abstract The ability to estimate the speed of an object irrespective size or texture is a crucial function visual system. However, previous studies have suggested that neuronal coding in middle temporal area (MT, key cortical for motion analysis primates) ambiguous, with most neurons changing their tuning depending on spatial frequency (SF) pattern. Here we demonstrate MT encode markedly improved when stimuli follow trajectory across field, prior entering receptive fields. We also show this...

Abstract Adjacent neurons in visual cortex have overlapping receptive fields within and across area boundaries, an arrangement which is theorized to minimize wiring cost. This constraint thought create retinotopic maps of opposing field sign (mirror non-mirror representations the field) adjacent areas, a concept has become central current attempts subdivide cortex. We modelled realistic developmental scenario areas do not mature simultaneously, but need maintain topographic continuity their...