Conserved patterns of cortico-cortical connections define areal hierarchy in rat visual cortex

Coogan, Thomas A.; Burkhalter, Andreas

doi:10.1007/bf00228846

Cited by 95 publications

(72 citation statements)

References 28 publications

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“…These findings differ from an earlier report by Miller and Vogt (1984); the difference may be attributed to the greater sensitivity and resolution of the tracer used by Coogan and Burkhalter (1990). The available evidence suggests that there are at least 3 hierarchical levels involving 5 visual areas in the rat.…”

Section: Other Speciescontrasting

confidence: 88%

“…In the rat, a recent study by Coogan and Burkhalter (1990) has revealed consistent asymmetries in anterograde labeling patterns between visual areas, in a manner strongly analogous to the hierarchical relations we have described for primates. These findings differ from an earlier report by Miller and Vogt (1984); the difference may be attributed to the greater sensitivity and resolution of the tracer used by Coogan and Burkhalter (1990).…”

Section: Other Speciessupporting

confidence: 79%

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Distributed Hierarchical Processing in the Primate Cerebral Cortex

Felleman¹,

1991

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In recent years, many new cortical areas have been identified in the macaque monkey. The number of identified connections between areas has increased even more dramatically. We report here on (1) a summary of the layout of cortical areas associated with vision and with other modalities, (2) a computerized database for storing and representing large amounts of information on connectivity patterns, and (3) the application of these data to the analysis of hierarchical organization of the cerebral cortex. Our analysis concentrates on the visual system, which includes 25 neocortical areas that are predominantly or exclusively visual in function, plus an additional 7 areas that we regard as visual-association areas on the basis of their extensive visual inputs. A total of 305 connections among these 32 visual and visual-association areas have been reported. This represents 31 % of the possible number of pathways if each area were connected with all others. The actual degree of connectivity is likely to be closer to 40%. The great majority of pathways involve reciprocal connections between areas. There are also extensive connections with cortical areas outside the visual system proper, including the somatosensory cortex, as well as neocortical, transitional, and archicortical regions in the temporal and frontal lobes. In the somatosensory/motor system, there are 62 identified pathways linking 13 cortical areas, suggesting an overall connectivity of about 40%. Based on the laminar patterns of connections between areas, we propose a hierarchy of visual areas and of somatosensory/motor areas that is more comprehensive than those suggested in other recent studies. The current version of the visual hierarchy includes 10 levels of cortical processing. Altogether, it contains 14 levels if one includes the retina and lateral geniculate nucleus at the bottom as well as the entorhinal cortex and hippocampus at the top. Within this hierarchy, there are multiple, intertwined processing streams, which, at a low level, are related to the compartmental organization of areas VI and V2 and, at a high level, are related to the distinction between processing centers in the temporal and parietal lobes. However, there are some pathways and relationships (about 10% of the total) whose descriptions do not fit cleanly into this hierarchical scheme for one reason or another. In most instances, though, it is unclear whether these represent genuine exceptions to a strict hierarchy rather than inaccuracies or uncertainties in the reported assignment.During the past decade, there has been an explosion of information about the organization and connectivity of sensory and motor areas in the mammalian cerebral cortex. Many laboratories have concentrated their efforts on the visual cortex of macaque monkeys, whose superb visual capacities in many ways rival those of humans. In this article, we survey recent progress in charting the layout of different cortical areas in the macaque and in analyzing the hierarchical relationships among these areas, part...

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Section: Other Speciescontrasting

confidence: 88%

Section: Other Speciessupporting

confidence: 79%

Distributed Hierarchical Processing in the Primate Cerebral Cortex

Felleman¹,

1991

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“…Because perirhinal cortex lesions are sufficient to produce this visual object recognition memory deficit (Meunier et al 1993;Gaffan 1994;Buckley et al 1997) and entorhinal cortex lesions only produce transient effects (Leonard et al 1995), it appears that the perirhinal cortex is essential for visual object recognition memory. On the basis of anatomical evidence, a similar hierarchical organization has been uncovered in the rat between primary visual cortex and medial and lateral extrastriate visual cortex, temporal (TE 2 ) cortex, and perirhinal cortex (Deacon et al 1983;Miller and Vogt 1984;Coogan and Burkhalter 1990;Sanderson et al 1991;Vaudana et al 1991). The medial extrastriate visual cortex has been identified as an important substrate in mediating memory for visual object information .…”

mentioning

confidence: 87%

A Neural Circuit Analysis of Visual Recognition Memory: Role of Perirhinal, Medial, and Lateral Entorhinal Cortex

Kesner

Ravindranathan²,

Jackson³

et al. 2001

Learn. Mem.

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Using a continuous recognition memory procedure for visual object information, we sequentially presented rats with eight novel objects and four repeated objects (chosen from the 8). These were selected from 120 different three-dimensional objects of varying sizes, shapes, textures, and degree of brightness. Repeated objects had lags ranging from 0 to 4 (from 0 to 4 different objects between the first and repeated presentation). An object was presented on one side of a long table divided in half by an opaque Plexiglas guillotine door, and the latency between opening the door and the rat moving the object was measured. The first presentation of an object resulted in reinforcement, but repeated presentations did not result in a reinforcement. After completion of acquisition training (significantly longer latencies for repeated presentation compared with the first presentation of an object), rats received lesions of the perirhinal, medial, or lateral entorhinal cortex or served as sham operated controls. On the basis of postsurgery testing and additional tests, the results indicated that rats with perirhinal cortex lesions had a sustained impairment in performing the task. There were no sustained deficits with medial or lateral entorhinal cortex lesions. The data suggest that recognition memory for visual object information is mediated primarily by the perirhinal cortex but not by the medial or lateral entorhinal cortex.

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“…While bottom-up fibers terminate predominantly in cortical layer 4 of the target area, top-down fibers target mainly layer 1, [30][31][32][33][34] where they contact primarily apical dendrites of pyramidal neurons located in layers 2, 3, and 5. Traditionally, dendrites were thought to be passive conduction elements: the excitatory and inhibitory potentials induced at their synapses would be relayed to the cell soma simply via electrotonic spread, diminishing exponentially along the way.…”

Section: The Effects Of General Anesthetics On Apical Dendrites Of Pymentioning

confidence: 99%

“…It is by now well established that there are reciprocal anatomical connections at all stages of sensory processing for at least the visual, [30][31][32]65 auditory, 33,65 and somatosensory 34,65,66 modalities. In fact, area V1 receives top-down projections from more areas than it sends bottom-up projections to, and there appears to be a general predominance of topdown over bottom-up connectivity along the ventral visual pathway.…”

Section: Top-down Signals and Conscious Perception: What We Already Knowmentioning

confidence: 99%

The Role of Dendritic Signaling in the Anesthetic Suppression of Consciousness

Meyer

2015

Anesthesiology

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Despite considerable progress in the identification of the molecular targets of general anesthetics, it remains unclear how these drugs affect the brain at the systems level to suppress consciousness. According to recent proposals, anesthetics may achieve this feat by interfering with corticocortical topdown processes, that is, by interrupting information flow from association to early sensory cortices. Such a view entails two immediate questions. First, at which anatomical site, and by virtue of which physiological mechanism, do anesthetics interfere with top-down signals? Second, why does a breakdown of top-down signaling cause unconsciousness? While an answer to the first question can be gleaned from emerging neurophysiological evidence on dendritic signaling in cortical pyramidal neurons, a response to the second is offered by increasingly popular theoretical frameworks that place the element of prediction at the heart of conscious perception. Science magazine posed this question in a special section titled "What don't we know?," dedicated to the greatest challenges of contemporary science. 1 "Scientists are chipping away at the drugs' effects on individual neurons," the article reads, "but understanding how they render us unconscious will be a tougher nut to crack." This prediction proved correct: a decade later, we have expanded considerably our knowledge of the molecular targets of general anesthetics, but it remains enigmatic how these drugs affect the brain at the systems level. Why does the potentiation of γ-aminobutyric acid (GABA) receptors caused by propofol or desflurane cause unconsciousness? How are the brain's computational processes affected by this and other molecular mechanisms of anesthetics, so that patients undergoing surgery cease to experience their surrounds in terms of sight, sound, and touch? Anesthesiologists and cognitive neuroscientists alike have been captivated by these questions and have proposed a number of models in an attempt to answer them, such as Flohr's "information processing theory of anesthesia," 2 Alkire's "thalamic consciousness switch hypothesis," 3-6 Mashour's "cognitive unbinding paradigm," 7,8 John and Prichep's "anesthetic cascade," 9 or Hudetz's "forgotten present." 10,11 We shall return to some of these frameworks in a later section of the article.One recent development is particularly intriguing. Given that the most striking feature of general anesthesia is an interruption of the patient's ability to perceive the environment, it would appear intuitive for anesthetics to interfere primarily with bottom-up information flow along the sensory pathways, that is, with the signals that carry perceptual information from the thalamus to the primary sensory cortices and on to unimodal and multimodal association cortices. However, the very opposite appears to be the case. Several recent studies-carried out in both humans and animals, and using a variety of different anesthetic agents-have investigated differences in directional corticocortical connectivity bet...

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Conserved patterns of cortico-cortical connections define areal hierarchy in rat visual cortex

Cited by 95 publications

References 28 publications

Distributed Hierarchical Processing in the Primate Cerebral Cortex

Distributed Hierarchical Processing in the Primate Cerebral Cortex

A Neural Circuit Analysis of Visual Recognition Memory: Role of Perirhinal, Medial, and Lateral Entorhinal Cortex

The Role of Dendritic Signaling in the Anesthetic Suppression of Consciousness

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