Plasticity in the acquisition of multisensory integration capabilities in superior colliculus

2012 ◽  
Vol 25 (0) ◽  
pp. 133
Author(s):  
Barry E. Stein ◽  
Liping Yu ◽  
Jinghong Xu ◽  
Benjamin A. Rowland
Keyword(s):  
Superior Colliculus ◽  
Multisensory Integration ◽  
Light Flash ◽  
Postnatal Life ◽  
Ambient Sound ◽  
Co Activation ◽  
Temporal Coupling ◽  
Maturational Process ◽  
Hebbian Mechanisms

The multisensory integration capabilities of superior colliculus (SC) neurons are normally acquired during early postnatal life and adapted to the environment in which they will be used. Recent evidence shows that they can even be acquired in adulthood, and require neither consciousness nor any of the reinforcement contingencies generally associated with learning. This process is believed to be based on Hebbian mechanisms, whereby the temporal coupling of multiple sensory inputs initiates development of a means of integrating their information. This predicts that co-activation of those input channels is sufficient to induce multisensory integration capabilities regardless of the specific spatiotemporal properties of the initiating stimuli. However, one might expect that the stimuli to be integrated should be consonant with the functional role of the neurons involved. For the SC, this would involve stimuli that can be localized. Experience with a non-localizable cue in one modality (e.g., ambient sound) and a discrete stimulus in another (e.g., a light flash) should not be sufficient for this purpose. Indeed, experiments with cats reared in omnidirectional sound (effectively masking discrete auditory events) reveal that the simple co-activation of two sensory input channels is not sufficient for this purpose. The data suggest that experience with the kinds of cross-modal events that facilitate the role of the SC in detecting, locating, and orienting to localized external events is a guiding factor in this maturational process. Supported by NIH grants NS 036916 and EY016716.

scholarly journals Sound Richness of Music Might Be Mediated by Color Perception: A PET Study

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Masayuki Satoh ◽  
Ken Nagata ◽  
Hidekazu Tomimoto
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Multisensory Integration ◽  
Regional Cerebral Blood Flow ◽  
Traditional Music ◽  
Simple Condition ◽  
Regional Cerebral Blood ◽  
Subtraction Technique ◽  
Posterior Portion

Objects. We investigated the role of the fusiform cortex in music processing with the use of PET, focusing on the perception of sound richness.Method. Musically naïve subjects listened to familiar melodies with three kinds of accompaniments: (i) an accompaniment composed of only three basic chords (chord condition), (ii) a simple accompaniment typically used in traditional music text books in elementary school (simple condition), and (iii) an accompaniment with rich and flowery sounds composed by a professional composer (complex condition). Using a PET subtraction technique, we studied changes in regional cerebral blood flow (rCBF) in simple minus chord, complex minus simple, and complex minus chord conditions.Results. The simple minus chord, complex minus simple, and complex minus chord conditions regularly showed increases in rCBF at the posterior portion of the inferior temporal gyrus, including the LOC and fusiform gyrus.Conclusions. We may conclude that certain association cortices such as the LOC and the fusiform cortex may represent centers of multisensory integration, with foreground and background segregation occurring at the LOC level and the recognition of richness and floweriness of stimuli occurring in the fusiform cortex, both in terms of vision and audition.

Effects of Local Nicotinic Activation of the Superior Colliculus on Saccades in Monkeys

2005 ◽  
Vol 93 (1) ◽  
pp. 519-534 ◽  
Author(s):  
Masayuki Watanabe ◽  
Yasushi Kobayashi ◽  
Yuka Inoue ◽  
Tadashi Isa
Keyword(s):  
Superior Colliculus ◽  
Reaction Times ◽  
Low Frequency ◽  
Visually Guided ◽  
Population Activity ◽  
Affected Area ◽  
Movement Field ◽  
Neural Interactions ◽  
Restricted Region

To examine the role of competitive and cooperative neural interactions within the intermediate layer of superior colliculus (SC), we elevated the basal SC neuronal activity by locally injecting a cholinergic agonist nicotine and analyzed its effects on saccade performance. After microinjection, spontaneous saccades were directed toward the movement field of neurons at the injection site (affected area). For visually guided saccades, reaction times were decreased when targets were presented close to the affected area. However, when visual targets were presented remote from the affected area, reaction times were not increased regardless of the rostrocaudal level of the injection sites. The endpoints of visually guided saccades were biased toward the affected area when targets were presented close to the affected area. After this endpoint effect diminished, the trajectories of visually guided saccades remained modestly curved toward the affected area. Compared with the effects on endpoints, the effects on reaction times were more localized to the targets close to the affected area. These results are consistent with a model that saccades are triggered by the activities of neurons within a restricted region, and the endpoints and trajectories of the saccades are determined by the widespread population activity in the SC. However, because increased reaction times were not observed for saccades toward targets remote from the affected area, inhibitory interactions in the SC may not be strong enough to shape the spatial distribution of the low-frequency preparatory activities in the SC.

scholarly journals The role of infant nutrition in the global epidemic of non-communicable disease

2016 ◽  
Vol 75 (2) ◽  
pp. 162-168 ◽  
Author(s):  
Atul Singhal
Keyword(s):  
Early Life ◽  
Infant Nutrition ◽  
Communicable Disease ◽  
Bottle Feeding ◽  
Postnatal Life ◽  
World Region ◽  
Global Epidemic ◽  
Main Determinants ◽  
The Impact

Non-communicable diseases (NCD) and atherosclerotic CVD in particular, are the most important health problems of the 21st century. Already in every world region except Africa, NCD account for greater mortality than communicable, maternal, perinatal and nutritional conditions combined. Although modifiable lifestyle factors in adults are the main determinants, substantial evidence now suggests that factors in early life also have a major role in the development of NCD; commonly referred to as the Developmental Origins of Health and Disease hypothesis. Factors in utero, early postnatal life and throughout childhood, have been shown to affect NCD by influencing risk factors for CVD such as obesity, diabetes, hypertension and dyslipidaemia. Infant nutrition (e.g. breastfeeding rather than bottle feeding) and a slower pattern of infant weight gain have been shown to be particularly protective against later risk of obesity and CVD in both low- and high-income countries. The mechanisms involved are poorly understood, but include epigenetic changes; effects on endocrine systems regulating body weight, food intake and fat deposition; and changes in appetite regulation. As a consequence, strategies to optimise early life nutrition could make a major contribution to stemming the current global epidemic of NCD. This review will consider the role of early life factors in the development of NCD, focusing on the impact of infant nutrition/growth on obesity and CVD. The review will highlight the experimental (randomised) evidence where available, briefly summarise the underlying mechanisms involved and consider the implications for public health.

scholarly journals What does a neuron learn from multisensory experience?

2015 ◽  
Vol 113 (3) ◽  
pp. 883-889 ◽  
Author(s):  
Jinghong Xu ◽  
Liping Yu ◽  
Terrence R. Stanford ◽  
Benjamin A. Rowland ◽  
Barry E. Stein
Keyword(s):  
Superior Colliculus ◽  
Early Life ◽  
Life Experience ◽  
Sensory Experience ◽  
Rearing Environment ◽  
Early Life Experience ◽  
Environmental Events ◽  
Cat Superior Colliculus ◽  
Maturational Process ◽  
Multisensory Experience

The brain's ability to integrate information from different senses is acquired only after extensive sensory experience. However, whether early life experience instantiates a general integrative capacity in multisensory neurons or one limited to the particular cross-modal stimulus combinations to which one has been exposed is not known. By selectively restricting either visual-nonvisual or auditory-nonauditory experience during the first few months of life, the present study found that trisensory neurons in cat superior colliculus (as well as their bisensory counterparts) became adapted to the cross-modal stimulus combinations specific to each rearing environment. Thus, even at maturity, trisensory neurons did not integrate all cross-modal stimulus combinations to which they were capable of responding, but only those that had been linked via experience to constitute a coherent spatiotemporal event. This selective maturational process determines which environmental events will become the most effective targets for superior colliculus-mediated shifts of attention and orientation.

The Effects of Cue Reliability on Crossmodal Recalibration in Adults and Children

2021 ◽  
pp. 1-19
Author(s):  
Sophie Rohlf ◽  
Patrick Bruns ◽  
Brigitte Röder
Keyword(s):  
Multisensory Integration ◽  
Sound Localization ◽  
Visual Stimulus ◽  
Cue Combination ◽  
Single Exposure ◽  
Visual Cue ◽  
Cue Reliability ◽  
Adults And Children ◽  
Ventriloquist Effect

Abstract Reliability-based cue combination is a hallmark of multisensory integration, while the role of cue reliability for crossmodal recalibration is less understood. The present study investigated whether visual cue reliability affects audiovisual recalibration in adults and children. Participants had to localize sounds, which were presented either alone or in combination with a spatially discrepant high- or low-reliability visual stimulus. In a previous study we had shown that the ventriloquist effect (indicating multisensory integration) was overall larger in the children groups and that the shift in sound localization toward the spatially discrepant visual stimulus decreased with visual cue reliability in all groups. The present study replicated the onset of the immediate ventriloquist aftereffect (a shift in unimodal sound localization following a single exposure of a spatially discrepant audiovisual stimulus) at the age of 6–7 years. In adults the immediate ventriloquist aftereffect depended on visual cue reliability, whereas the cumulative ventriloquist aftereffect (reflecting the audiovisual spatial discrepancies over the complete experiment) did not. In 6–7-year-olds the immediate ventriloquist aftereffect was independent of visual cue reliability. The present results are compatible with the idea of immediate and cumulative crossmodal recalibrations being dissociable processes and that the immediate ventriloquist aftereffect is more closely related to genuine multisensory integration.

scholarly journals Multisensory Integration in the Superior Colliculus of the Alert Cat

1998 ◽  
Vol 80 (2) ◽  
pp. 1006-1010 ◽  
Author(s):  
Mark T. Wallace ◽  
M. Alex Meredith ◽  
Barry E. Stein
Keyword(s):  
Superior Colliculus ◽  
Multisensory Integration ◽  
Sensory Response ◽  
Functional Link ◽  
Sensory Stimuli ◽  
Response Properties ◽  
Alert Cat

Wallace, Mark T., M. Alex Meredith, and Barry E. Stein. Multisensory integration in the superior colliculus of the alert cat. J. Neurophysiol. 80: 1006–1010, 1998. The modality convergence patterns, sensory response properties, and principles governing multisensory integration in the superior colliculus (SC) of the alert cat were found to have fundamental similarities to those in anesthetized animals. Of particular interest was the observation that, in a manner indistinguishable from the anesthetized animal, combinations of two different sensory stimuli significantly enhanced the responses of SC neurons above those evoked by either unimodal stimulus. These observations are consistent with the speculation that there is a functional link among multisensory integration in individual SC neurons and cross-modality attentive and orientation behaviors.

GABAA and GABAC Receptors Have Contrasting Effects on Excitability in Superior Colliculus

1999 ◽  
Vol 82 (4) ◽  
pp. 2020-2023 ◽  
Author(s):  
Michael Pasternack ◽  
Mathias Boller ◽  
Belinda Pau ◽  
Matthias Schmidt
Keyword(s):  
Superior Colliculus ◽  
Receptor Agonist ◽  
Brain Slices ◽  
Superficial Layer ◽  
Field Potentials ◽  
Competitive Antagonist ◽  
Postsynaptic Potential ◽  
Late Potential ◽  
Receptor Agonists And Antagonists

We have recently found that GABAC receptor subunit transcripts are expressed in the superficial layers of rat superior colliculus (SC). In the present study we used immunocytochemistry to demonstrate the presence of GABAC receptors in rat SC at protein level. We also investigated in acute rat brain slices the effect of GABAA and GABAC receptor agonists and antagonists on stimulus-evoked extracellular field potentials in SC. Electrical stimulation of the SC optic layer induced a biphasic, early and late, potential in the adjacent superficial layer. The late component was completely inhibited by 6-cyano-7-nitroquinoxaline-2,3-dione or CoCl2, indicating that it was generated by postsynaptic activation. Muscimol, a potent GABAA and GABAC receptor agonist, strongly attenuated this postsynaptic potential at concentrations >10 μM. In contrast, the GABAC receptor agonist cis-aminocrotonic acid, as well as muscimol at lower concentrations (0.1–1 μM) increased the postsynaptic potential. This increase was blocked by (1,2,5,6-tetrahydropyridine-4-yl)methylphosphinic acid, a novel competitive antagonist of GABAC receptors. Our findings demonstrate the presence of functional GABAC receptors in SC and suggest a disinhibitory role of these receptors in SC neuronal circuitry.

scholarly journals Amygdala Underlies the Environment Dependency of Defense Responses Induced via Superior Colliculus

2022 ◽  
Vol 15 ◽  
Author(s):  
Kaoru Isa ◽  
Kota Tokuoka ◽  
Sakura Ikeda ◽  
Sara Karimi ◽  
Kenta Kobayashi ◽  
...  
Keyword(s):  
Superior Colliculus ◽  
Natural Environment ◽  
Ibotenic Acid ◽  
Defense Responses ◽  
Male Mice ◽  
Contextual Modulation ◽  
Innate Defense ◽  
Open Platform ◽  
Environmental Setting

In our previous study, we showed that the defense responses induced by the selective optogenetic activation of the uncrossed output pathway from the deeper layer of the superior colliculus were environment dependent in the mouse. In a small closed box, the stimulus frequently induced flight (fast forward run away) responses, while in a large open field, the stimulus tended to induce backward retreat responses. We tested a hypothesis that the amygdala is involved in such environment dependency of the innate defense responses. For this purpose, we made a bilateral lesion of the amygdala induced by the ibotenic acid injections in male mice. As a result, in the mice with lesions of substantial portions of the basolateral and basomedial complex, the flight responses in the closed box disappeared and retreat responses were mainly induced. The retreat responses on the open platform were unchanged. Classically, the amygdala has been considered to be involved in the memory-dependent contextual modulation of the fear responses. In contrast, the present results suggest a novel view on the role of the amygdala in which the amygdala plays a key role in sensing the current environmental setting for making a quick decision of action upon emergency, which is critical for survival in the natural environment.

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