Auditory cortical projection from the anterior ectosylvian sulcus (Field AES) to the superior colliculus in the cat: An anatomical and electrophysiological study

1989 ◽  
Vol 289 (4) ◽  
pp. 687-707 ◽  
Author(s):  
M. Alex Meredith ◽  
H. Ruth Clemo
Keyword(s):  
Superior Colliculus ◽  
Electrophysiological Study ◽  
Cortical Projection ◽  
Anterior Ectosylvian Sulcus

Corticotectal and corticothalamic efferent projections of SIV somatosensory cortex in cat

1983 ◽  
Vol 50 (4) ◽  
pp. 896-909 ◽  
Author(s):  
B. E. Stein ◽  
R. F. Spencer ◽  
S. B. Edwards
Keyword(s):  
Superior Colliculus ◽  
Somatosensory Cortex ◽  
Species Difference ◽  
Pyramidal Cells ◽  
Thalamic Nuclei ◽  
Anterior Ectosylvian Sulcus ◽  
Ventrobasal Complex ◽  
Posterior Group ◽  
Corticothalamic Projection ◽  
Efferent Projections

Substantial corticotectal (and corticothalamic) projections from the cortex of the anterior ectosylvian sulcus (AES) were demonstrated in the cat using the axonal transport methods of autoradiography and horseradish peroxidase. The corticotectal projection arises nearly exclusively from medium-large pyramidal cells in lamina V. One of the densest projecting areas of the AES is the rostral aspect of its superior bank, where a fourth somatotopic representation (SIV) has recently been demonstrated. It terminates in the intermediate and deep laminae of the superior colliculus, where somatic cells are located. The pathway is bilateral but much heavier ipsilaterally than contralaterally. In contrast to the substantial corticotectal projection from SIV and adjacent tissue, there was no unequivocal evidence for a corticotectal projection from traditional somatosensory cortex SI-SIII. This finding, that somatosensory projections to the cat superior colliculus arise from an area outside of SI-SIII, was unexpected on the basis of what is known about visual corticotectal projections. However, it is consistent with the patterns of other cortical projections that terminate in the intermediate and deep laminae of this structure and with the absence of demonstrable corticotectal influences from SI to SIII in this animal. These data are in contrast to demonstrations by other investigators that there is a corticotectal projection from SI cortex in rodents. Apparently there is a fundamental species difference in the organization of descending somatosensory pathways. A corticothalamic projection of the AES was also observed. This descending projection appeared to form a shell of labeled cells and fibers around the ventrobasal complex, but unequivocal terminal labeling within the ventrobasal complex could not be demonstrated. Dense terminal labeling was apparent in the posterior group of thalamic nuclei (PO) where thalamocortical afferents to the AES originate.

Cross-modal synthesis in the midbrain depends on input from cortex

1994 ◽  
Vol 71 (1) ◽  
pp. 429-432 ◽  
Author(s):  
M. T. Wallace ◽  
B. E. Stein
Keyword(s):  
Superior Colliculus ◽  
Specific Effect ◽  
Association Cortex ◽  
Anterior Ectosylvian Sulcus ◽  
Modal Synthesis ◽  
Sensory Modalities ◽  
Superior Colliculus Neurons ◽  
Multisensory Information ◽  
Associative Functions ◽  
Unimodal Cues

1. The synthesis of information from different sensory modalities in the superior colliculus is an important precursor of attentive and orientation behavior. 2. This integration of multisensory information is critically dependent on inputs from a small area of association cortex, the anterior ectosylvian sulcus. Removal of these corticotectal influences can have a remarkably specific effect: it can eliminate multisensory integration in superior colliculus neurons while leaving their responses to unimodal cues intact. 3. Apparently, some of the associative functions of cortex are accomplished via its target neurons in the midbrain.

scholarly journals Neonatal Cortical Ablation Disrupts Multisensory Development in Superior Colliculus

2006 ◽  
Vol 95 (3) ◽  
pp. 1380-1396 ◽  
Author(s):  
Wan Jiang ◽  
Huai Jiang ◽  
Barry E. Stein
Keyword(s):  
Superior Colliculus ◽  
Normal Development ◽  
Receptive Fields ◽  
Early Ontogeny ◽  
Neonatal Brain ◽  
Anterior Ectosylvian Sulcus ◽  
Cortical Ablation ◽  
Cat Superior Colliculus ◽  
Multisensory Processes ◽  
Normal Adults

The ability of cat superior colliculus (SC) neurons to synthesize information from different senses depends on influences from two areas of the cortex: the anterior ectosylvian sulcus (AES) and the rostral lateral suprasylvian sulcus (rLS). Reversibly deactivating the inputs to the SC from either of these areas in normal adults severely compromises this ability and the SC-mediated behaviors that depend on it. In this study, we found that removal of these areas in neonatal animals precluded the normal development of multisensory SC processes. At maturity there was a substantial decrease in the incidence of multisensory neurons, and those multisensory neurons that did develop were highly abnormal. Their cross-modal receptive field register was severely compromised, as was their ability to integrate cross-modal stimuli. Apparently, despite the impressive plasticity of the neonatal brain, it cannot compensate for the early loss of these cortices. Surprisingly, however, neonatal removal of either AES or rLS had comparatively minor consequences on these properties. At maturity multisensory SC neurons were quite common: they developed the characteristic spatial register among their unisensory receptive fields and exhibited normal adult-like multisensory integration. These observations suggest that during early ontogeny, when the multisensory properties of SC neurons are being crafted, AES and rLS may have the ability to compensate for the loss of one another's cortico-collicular influences so that normal multisensory processes can develop in the SC.

An electrophysiological study of the visual projection to the superior colliculus of the rat

1966 ◽  
Vol 127 (4) ◽  
pp. 435-444 ◽  
Author(s):  
Robert Siminoff ◽  
Horst Otto Schwassmann ◽  
Lawrence Kruger
Keyword(s):  
Superior Colliculus ◽  
Electrophysiological Study ◽  
Visual Projection

Converging influences from visual, auditory, and somatosensory cortices onto output neurons of the superior colliculus

1993 ◽  
Vol 69 (6) ◽  
pp. 1797-1809 ◽  
Author(s):  
M. T. Wallace ◽  
M. A. Meredith ◽  
B. E. Stein
Keyword(s):  
Superior Colliculus ◽  
Principal Component ◽  
Anterior Ectosylvian Sulcus ◽  
Cortical Input ◽  
Functional Roles ◽  
Somatosensory Cortices ◽  
Sensory Cortices ◽  
Output Neurons ◽  
Superior Colliculus Neurons ◽  
Cortical Inputs

1. Physiological methods were used to examine the pattern of inputs from different sensory cortices onto individual superior colliculus neurons. 2. Visual, auditory, and somatosensory influences from anterior ectosylvian sulcus (AES) and visual influences from lateral suprasylvian (LS) cortex were found to converge onto individual multisensory neurons in the cat superior colliculus. An excellent topographic relationship was found between the different sensory cortices and their target neurons in the superior colliculus. 3. Corticotectal inputs were derived solely from unimodal neurons. Multisensory neurons in AES and LS were not antidromically activated from the superior colliculus. 4. Orthodromic and antidromic latencies were consistent with monosynaptic corticotectal inputs arising from LS and the three subdivisions of AES (SIV, Field AES, and AEV). 5. Superior colliculus neurons that received convergent cortical inputs formed a principal component of the tecto-reticulospinal tract. Thus there appears to be extensive cortical control over the output neurons through which the superior colliculus mediates attentive and orientation behaviors. 6. Two other multisensory circuits were identified. A population of multisensory superior colliculus neurons was found, which neither received convergent cortical input nor projected into the tecto-reticulo-spinal tract. In addition, multisensory neurons in AES and LS proved to be independent of the superior colliculus (i.e., they were not corticotectal). While it is likely that these three distinct multisensory neural circuits have different functional roles, their constituent neurons appear to integrate their various sensory inputs in much the same way.

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