Perirhinal and parahippocampal cortices of the macaque monkey: Cortical afferents

1994 ◽  
Vol 350 (4) ◽  
pp. 497-533 ◽  
Author(s):  
Wendy L. Suzuki ◽  
David G. Amaral
Keyword(s):  
Macaque Monkey ◽  
Cortical Afferents

Macaque monkey retrosplenial cortex: II. Cortical afferents

2003 ◽  
Vol 466 (1) ◽  
pp. 48-79 ◽  
Author(s):  
Yasushi Kobayashi ◽  
David G. Amaral
Keyword(s):  
Macaque Monkey ◽  
Retrosplenial Cortex ◽  
Cortical Afferents

scholarly journals Cortical Afferents of Area 10 in Cebus Monkeys: Implications for the Evolution of the Frontal Pole

2018 ◽  
Vol 29 (4) ◽  
pp. 1473-1495 ◽  
Author(s):  
Marcello G P Rosa ◽  
Juliana G M Soares ◽  
Tristan A Chaplin ◽  
Piotr Majka ◽  
Sophia Bakola ◽  
...  
Keyword(s):  
Regional Differences ◽  
Macaque Monkey ◽  
Association Cortex ◽  
Temporal Association ◽  
Anatomical Connectivity ◽  
Frontal Pole ◽  
Cebus Monkey ◽  
Marmoset Monkey ◽  
Cortical Afferents ◽  
Cebus Monkeys

Abstract Area 10, located in the frontal pole, is a unique specialization of the primate cortex. We studied the cortical connections of area 10 in the New World Cebus monkey, using injections of retrograde tracers in different parts of this area. We found that injections throughout area 10 labeled neurons in a consistent set of areas in the dorsolateral, ventrolateral, orbital, and medial parts of the frontal cortex, superior temporal association cortex, and posterior cingulate/retrosplenial region. However, sites on the midline surface of area 10 received more substantial projections from the temporal lobe, including clear auditory connections, whereas those in more lateral parts received >90% of their afferents from other frontal areas. This difference in anatomical connectivity reflects functional connectivity findings in the human brain. The pattern of connections in Cebus is very similar to that observed in the Old World macaque monkey, despite >40 million years of evolutionary separation, but lacks some of the connections reported in the more closely related but smaller marmoset monkey. These findings suggest that the clearer segregation observed in the human frontal pole reflects regional differences already present in early simian primates, and that overall brain mass influences the pattern of cortico-cortical connectivity.

Preplate neurons in embryonic mouse cortex: Ultrastructural observations using photoconversion of the fluorescent lipophilic dye dil

1992 ◽  
Vol 50 (1) ◽  
pp. 906-907
Author(s):  
Linda C. Hassinger ◽  
James E. Crandall
Keyword(s):  
Mouse Embryos ◽  
Embryonic Mouse ◽  
Cortical Afferents ◽  
Mouse Cortex ◽  
Carbocyanine Dye ◽  
Increased Sensitivity

We have begun to look directly at small numbers of afferent axons to early generated neurons that form the preplate in the developing mouse cortex. The carbocyanine dye Dil (1’1, dioctadecyl-3,3,3’3’-tetramethyl-indocarbocyanine) has proved especially useful for this goal. DiI labels axons and their terminals with greater sensitivity and without some of the disadvantages of axon filling with HRP. The increased sensitivity provided by labeling embryonic axons with DiI has given us new insights into the development of cortical afferents. For instance, we reported originally that afferents from the thalamus were present below the cortex as early as embryonic day 15 (E15) based on HRP injections into mouse embryos. By using DiI placements into the thalamus in aldehyde-fixed brains, we now know that thalamic fibers reach the cortex 24 hrs earlier.

scholarly journals An architectonic type principle in the development of laminar patterns of cortico-cortical connections

2021 ◽  
Author(s):  
Sarah F. Beul ◽  
Alexandros Goulas ◽  
Claus C. Hilgetag
Keyword(s):  
Structural Connectivity ◽  
Macaque Monkey ◽  
Brain Regions ◽  
Adult Brain ◽  
Mammalian Brain ◽  
Cortical Connections ◽  
Cortical Projections ◽  
Structural Connections ◽  
High Degree ◽  
The Brain

AbstractStructural connections between cortical areas form an intricate network with a high degree of specificity. Many aspects of this complex network organization in the adult mammalian cortex are captured by an architectonic type principle, which relates structural connections to the architectonic differentiation of brain regions. In particular, the laminar patterns of projection origins are a prominent feature of structural connections that varies in a graded manner with the relative architectonic differentiation of connected areas in the adult brain. Here we show that the architectonic type principle is already apparent for the laminar origins of cortico-cortical projections in the immature cortex of the macaque monkey. We find that prenatal and neonatal laminar patterns correlate with cortical architectonic differentiation, and that the relation of laminar patterns to architectonic differences between connected areas is not substantially altered by the complete loss of visual input. Moreover, we find that the degree of change in laminar patterns that projections undergo during development varies in proportion to the relative architectonic differentiation of the connected areas. Hence, it appears that initial biases in laminar projection patterns become progressively strengthened by later developmental processes. These findings suggest that early neurogenetic processes during the formation of the brain are sufficient to establish the characteristic laminar projection patterns. This conclusion is in line with previously suggested mechanistic explanations underlying the emergence of the architectonic type principle and provides further constraints for exploring the fundamental factors that shape structural connectivity in the mammalian brain.

scholarly journals Organization of the macaque monkey inferior parietal lobule based on multimodal receptor architectonics

NeuroImage ◽  
2021 ◽  
Vol 231 ◽  
pp. 117843 ◽  
Author(s):  
Meiqi Niu ◽  
Lucija Rapan ◽  
Thomas Funck ◽  
Seán Froudist-Walsh ◽  
Ling Zhao ◽  
...  
Keyword(s):  
Macaque Monkey ◽  
Inferior Parietal Lobule ◽  
Parietal Lobule

scholarly journals Pseudosparse neural coding in the visual system of primates

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Sidney R. Lehky ◽  
Keiji Tanaka ◽  
Anne B. Sereno
Keyword(s):  
Neural Coding ◽  
Macaque Monkey ◽  
Implicit Assumption ◽  
Data Set ◽  
Efficient Coding ◽  
Population Responses ◽  
Lateral Intraparietal Cortex ◽  
Neural Populations ◽  
Neurophysiological Data ◽  
The Mean

AbstractWhen measuring sparseness in neural populations as an indicator of efficient coding, an implicit assumption is that each stimulus activates a different random set of neurons. In other words, population responses to different stimuli are, on average, uncorrelated. Here we examine neurophysiological data from four lobes of macaque monkey cortex, including V1, V2, MT, anterior inferotemporal cortex, lateral intraparietal cortex, the frontal eye fields, and perirhinal cortex, to determine how correlated population responses are. We call the mean correlation the pseudosparseness index, because high pseudosparseness can mimic statistical properties of sparseness without being authentically sparse. In every data set we find high levels of pseudosparseness ranging from 0.59–0.98, substantially greater than the value of 0.00 for authentic sparseness. This was true for synthetic and natural stimuli, as well as for single-electrode and multielectrode data. A model indicates that a key variable producing high pseudosparseness is the standard deviation of spontaneous activity across the population. Consistently high values of pseudosparseness in the data demand reconsideration of the sparse coding literature as well as consideration of the degree to which authentic sparseness provides a useful framework for understanding neural coding in the cortex.

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