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 human cerebral cortex undergoes a protracted, regionally heterogeneous development well into young adulthood. Cortical areas that expand the most during correspond to those differ markedly when brains of macaque monkeys and humans are compared. However, it remains unclear what extent this relationship derives from allometric scaling laws apply primate in general, or represents unique evolutionary adaptations. Furthermore, is unknown whether only applies surface area (SA), also holds for...

The dendritic morphology of pyramidal cells located at the base layer III in primary visual area (V1), second (V2), middle temporal (MT), ventral portion lateral intraparietal (LIPv) and cytoarchitectonic 7a within anterior bank superior sulcus was revealed by injecting neurons with Lucifer Yellow fixed, flattened slices macaque monkey cortex. These areas correspond to different levels occipitoparietal cortical 'stream', which processes information related motion spatial relationships field....

Visual receptive fields (RFs) were mapped inside and outside the cortical representation of optic disk in striate cortex (area V1) anesthetized paralyzed Cebus monkeys. Unexpectedly, most cells found to be binocularly driven, RFs with contralateral-eye stimulation progressed a topographically appropriate fashion as sector was crossed. Activation these neurons by contralateral eye shown depend on parts retina around disk. Outside representation, similar effect demonstrated obstructing...

It has been suggested that the development of cerebral cortex reflects its hierarchical organization, with primary sensory areas being first to reach structural and functional maturity, higher-order association last. In present study, we labelled New World marmoset monkeys late fetal early postnatal ages an antibody non-phosphorylated neurofilament, a marker maturation subset pyramidal cells. Supporting concept maturation, found at birth cells were in visual, auditory somatosensory areas,...

The basal dendritic arbors of layer III pyramidal neurons are known to vary systematically among primate visual areas. Generally, those in areas associated with "higher" level cortical processing have larger and more spinous arbors, which may be an important factor for determining function within these Moreover, the tangential area their proportional periodic supragranular patches intrinsic connections many different morphological parameters both axon sampling strategies cells However,...

Flowering plants in Australia have been geographically isolated for more than 34 million years. In the Northern Hemisphere, previous work has revealed a close fit between optimal discrimination capabilities of hymenopteran pollinators and flower colours that most frequently evolved. We collected spectral data from 111 Australian native flowers tested signal appearance considering colour potentially important pollinators. The highest frequency reflectance curves is consistent with reported...

Dexterous hands, used to manipulate food, tools, and other objects, are one of the hallmarks primate evolution. However, neural substrate fine manual control necessary for these behaviors remains unclear. Here, we describe functional organization parietal cortical areas 2 5 in cebus monkey. Whereas New World monkeys can be quite dexterous, possess a poorly developed area 5, only known use precision grip, thus have an extended repertoire behaviors. Unlike Monkeys, but much like macaque...

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...

Understanding the principles of neuronal connectivity requires tools for efficient quantification and visualization large datasets. The primate cortex is particularly challenging due to its complex mosaic areas, which in many cases lack clear boundaries. Here, we introduce a resource that allows exploration results 143 retrograde tracer injections marmoset neocortex. Data obtained different animals are registered common stereotaxic space using an algorithm guided by expert delineation...

The cerebral cortex of mammals exhibits intricate interareal wiring. Moreover, mammalian cortices differ vastly in size, cytological composition, and phylogenetic distance. Given such complexity pronounced species differences, it is a considerable challenge to decipher organizational principles connectomes. Here, we demonstrate species-specific species-general unifying linking the physical, cytological, connectional dimensions architecture mouse, cat, marmoset, macaque monkey. existence...

Abstract The marmoset monkey has become an important primate model in Neuroscience. Here, we characterize salient statistical properties of interareal connections the cerebral cortex, using data from retrograde tracer injections. We found that connectivity weights are highly heterogeneous, spanning 5 orders magnitude, and log-normally distributed. cortico-cortical network is dense, heterogeneous high specificity. reciprocal most prominent probability connection between 2 areas decays with...

Abstract The representation of the visual field in striate cortex (VI) was mapped with multiunit electrodes Cebus monkey. Nine apella , anesthetized N 2 O and immobilized pancuromium bromide were studied repeated recording sessions. In each hemisphere, VI contains a continuous contralateral hemifield. vertical meridian (VM) forms external border V1 except at anteriormost portion calcarine fissure. horizontal (HM) divides area so that lower is located dorsally, upper ventrally. convoluted...

Abstract We defined cortical areas involved in the analysis of motion far peripheral visual field, a poorly understood aspect processing primates. This was accomplished by small tracer injections within and around representations monocular field vision (‘temporal crescents’) middle temporal area (MT) marmoset monkeys. Quantitative analyses demonstrate that representation periphery receives specific connections from retrosplenial cortex (areas 23v prostriata), as well comparatively stronger...

On the basis of extracellular recordings in marmoset monkeys, we report on organisation middle temporal area (MT) and surrounding crescent (MTc). Area MT is approximately 5-mm long 2-mm wide, whereas MTc forms a crescent-shaped band cortex 1-mm wide. Neurones form first-order representation contralateral hemifield, those second-order with field discontinuity near horizontal meridian. The vertical meridian border between MTc. In both areas, fovea represented ventrocaudally, visual periphery...

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 describe the organization of dorsolateral frontal areas in marmoset monkeys using a combination architectural methods (Nissl, cytochrome oxidase, and myelin stains) injections fluorescent tracers extrastriate (the second visual area [V2], dorsomedial dorsoanterior [DM, DA], middle temporal crescent [MT, MTc], posterior parietal cortex [area 7]). Cytoarchitectural field 8 comprises three subdivisions: 8Av, 8Ad, 8B. The ventrolateral subdivision, forms principal source projections to...

The goal of the present study was to elucidate corticocortical afferent connections area V6Av, ventral subregion V6A, using retrograde neuronal tracers combined with physiological and cytoarchitectonic analyses in macaque monkey. results revealed that V6Av receives many its afferents from extrastriate V6, regions areas V2, V3, V4 subserving peripheral vision. Additional visual projections originate dorsal stream MT MST. Area does not receive directly V1; such were only observed when...

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...

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...