scholarly journals Crossed Connections From Insular Cortex to the Contralateral Thalamus

2021 ◽  
Vol 15 ◽  
Author(s):  
Tolulope Adeyelu ◽  
Tanya Gandhi ◽  
Charles C. Lee
Keyword(s):  
Sensory Information ◽  
Insular Cortex ◽  
Transgenic Mouse Line ◽  
Sensory Features ◽  
Corticothalamic Projection ◽  
Contralateral Projection ◽  
Sensitivity And Selectivity ◽  
Ipsilateral Projection ◽  
Bilateral Mechanism ◽  
Corticothalamic Projections

Sensory information in all modalities, except olfaction, is processed at the level of the thalamus before subsequent transmission to the cerebral cortex. This incoming sensory stream is refined and modulated in the thalamus by numerous descending corticothalamic projections originating in layer 6 that ultimately alter the sensitivity and selectivity for sensory features. In general, these sensory thalamo-cortico-thalamic loops are considered strictly unilateral, i.e., no contralateral crosstalk between cortex and thalamus. However, in contrast to this canonical view, we characterize here a prominent contralateral corticothalamic projection originating in the insular cortex, utilizing both retrograde tracing and cre-lox mediated viral anterograde tracing strategies with the Ntsr1-Cre transgenic mouse line. From our studies, we find that the insular contralateral corticothalamic projection originates from a separate population of layer 6 neurons than the ipsilateral corticothalamic projection. Furthermore, the contralateral projection targets a topographically distinct subregion of the thalamus than the ipsilateral projection. These findings suggest a unique bilateral mechanism for the top-down refinement of ascending sensory information.

scholarly journals Sensor-Level Wavelet Analysis Reveals EEG Biomarkers of Perceptual Decision-Making

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2461
Author(s):  
Alexander Kuc ◽  
Vadim V. Grubov ◽  
Vladimir A. Maksimenko ◽  
Natalia Shusharina ◽  
Alexander N. Pisarchik ◽  
...  
Keyword(s):  
Decision Making ◽  
Sensory Information ◽  
Stimulus Onset ◽  
Perceptual Process ◽  
Perceptual Decision Making ◽  
Beta Band ◽  
Perceptual Decision ◽  
Time Frequency ◽  
Band Power ◽  
Sensory Features

Perceptual decision-making requires transforming sensory information into decisions. An ambiguity of sensory input affects perceptual decisions inducing specific time-frequency patterns on EEG (electroencephalogram) signals. This paper uses a wavelet-based method to analyze how ambiguity affects EEG features during a perceptual decision-making task. We observe that parietal and temporal beta-band wavelet power monotonically increases throughout the perceptual process. Ambiguity induces high frontal beta-band power at 0.3–0.6 s post-stimulus onset. It may reflect the increasing reliance on the top-down mechanisms to facilitate accumulating decision-relevant sensory features. Finally, this study analyzes the perceptual process using mixed within-trial and within-subject design. First, we found significant percept-related changes in each subject and then test their significance at the group level. Thus, observed beta-band biomarkers are pronounced in single EEG trials and may serve as control commands for brain-computer interface (BCI).

Lingual Mechanoreceptive Information II

1982 ◽  
Vol 25 (3) ◽  
pp. 357-363
Author(s):  
James P. Bowman
Keyword(s):  
Trigeminal Nerve ◽  
Somatosensory System ◽  
Single Pulse ◽  
Lingual Nerve ◽  
Medial Lemniscus ◽  
Trigeminal Nuclei ◽  
Sensorimotor Activity ◽  
Contralateral Projection ◽  
Sensory Nucleus ◽  
Ipsilateral Projection

The extent to which the known trigeminothalamic projections are related to afferents from specific peripheral branches of the trigeminal nerve is not clearly revealed by degeneration studies involving lesions of the various trigeminal nuclei. This study examines the ascending projections related to the lingual branch of the trigeminal nerve using the evoked-potential technique in pentobarbital anesthetized rhesus monkeys. The distribution of potentials within the medulla, pons, and midbrain was determined by recording with macroelectrodes following single-pulse stimulation of the lingual nerve. Results show that two pathways from the main sensory nucleus convey lingual nerve information to the thalamic ventral posteromedial nucleus: an ipsilateral projection which in position corresponds to the dorsal trigeminal tract, and a larger contralateral projection which in position corresponds to the crossed ventral trigeminal tract, or trigeminal lemniscus. Additionally, the spinal trigeminal nucleus contributes fibers of lingual nerve origin to the contralateral medial lemniscus. The role of low-threshold mechanoreceptive information in lingual sensorimotor activity is discussed in relation to current concepts of somatosensory system function.

scholarly journals Refinement of the primate corticospinal pathway during prenatal development

2019 ◽  
Author(s):  
Ana Rita Ribeiro Gomes ◽  
Etienne Olivier ◽  
Herbert P. Killackey ◽  
Pascale Giroud ◽  
Michel Berland ◽  
...  
Keyword(s):  
Occipital Cortex ◽  
Prenatal Development ◽  
Zona Incerta ◽  
Central Nucleus ◽  
Projection Neurons ◽  
Subcortical Structures ◽  
Corticospinal Pathway ◽  
Contralateral Projection ◽  
Order Of Magnitude ◽  
Ipsilateral Projection

AbstractPerturbation of the developmental refinement of the corticospinal pathway leads to motor disorders. In non-primates developmental refinement is well documented, however in primates invasive investigations of the developing corticospinal pathway have been confined to neonatal and postnatal stages when refinement is relatively modest.Here, we investigated the developmental changes in the distribution of corticospinal projection neurons in cynomolgus monkey. Injections of retrograde tracer at the cervical levels of the spinal cord at embryonic day (E) 95 and E105 show that (i) areal distribution of back-labeled neurons is more extensive than in the neonate and dense labeling is found in prefrontal, limbic, temporal and occipital cortex; (ii) distributions of contra- and ipsilateral projecting corticospinal neurons are comparable in terms of location and numbers of labeled neurons, in contrast to the adult where the contralateral projection is an order of magnitude higher than the ipsilateral projection. Findings from one largely restricted injection suggest a hitherto unsuspected early innervation of the gray matter.In the fetus there was in addition dense labeling in the central nucleus of the amygdala, the hypothalamus, the subthalamic nucleus and the adjacent region of the zona incerta, subcortical structures with only minor projections in the adult control.

Insular cortex and neuropsychiatric disorders: A review of recent literature

2007 ◽  
Vol 22 (6) ◽  
pp. 387-394 ◽  
Author(s):  
M. Nagai ◽  
K. Kishi ◽  
S. Kato
Keyword(s):  
Sensory Information ◽  
Insular Cortex ◽  
Superior Temporal Gyrus ◽  
Neuropsychiatric Disorders ◽  
Anterior Cingulate ◽  
Association Cortex ◽  
Amygdaloid Body ◽  
Computer Search ◽  
Neuropsychiatric Diseases ◽  
Motor Information

AbstractThe insular cortex is located in the centre of the cerebral hemisphere, having connections with the primary and secondary somatosensory areas, anterior cingulate cortex, amygdaloid body, prefrontal cortex, superior temporal gyrus, temporal pole, orbitofrontal cortex, frontal and parietal opercula, primary and association auditory cortices, visual association cortex, olfactory bulb, hippocampus, entorhinal cortex, and motor cortex. Accordingly, dense connections exist among insular cortex neurons. The insular cortex is involved in the processing of visceral sensory, visceral motor, vestibular, attention, pain, emotion, verbal, motor information, inputs related to music and eating, in addition to gustatory, olfactory, visual, auditory, and tactile data. In this article, the literature on the relationship between the insular cortex and neuropsychiatric disorders was summarized following a computer search of the Pub-Med database. Recent neuroimaging data, including voxel based morphometry, PET and fMRI, revealed that the insular cortex was involved in various neuropsychiatric diseases such as mood disorders, panic disorders, PTSD, obsessive-compulsive disorders, eating disorders, and schizophrenia. Investigations of functions and connections of the insular cortex suggest that sensory information including gustatory, olfactory, visual, auditory, and tactile inputs converge on the insular cortex, and that these multimodal sensory information may be integrated there.

Current source density analysis of contra- and ipsilateral isthmotectal connections of the frog

2006 ◽  
Vol 23 (5) ◽  
pp. 713-719 ◽  
Author(s):  
NORIAKI HOSHINO ◽  
KAZUYA TSURUDOME ◽  
HIDEKI NAKAGAWA ◽  
NOBUYOSHI MATSUMOTO
Keyword(s):  
Current Source ◽  
Current Source Density ◽  
Source Density ◽  
Intracellular Study ◽  
Contralateral Projection ◽  
Ipsilateral Projection ◽  
Density Analysis ◽  
Output Neurons ◽  
Threat Avoidance ◽  
Electrophysiological Examination

The nucleus isthmi (NI) of the frog receives input from the ipsilateral optic tectum and projects back to both optic tecta. After ablation of NI, frogs display no visually elicited prey-catching or threat avoidance behavior. Neural mechanisms that underlie the loss of such important behavior have not been solved. Electrophysiological examination of the contralateral isthmotectal projection has proved that it contributes to binocular vision. On the other hand, there are very few physiological investigations of the ipsilateral isthmotectal projection. In this study, current source density (CSD) analysis was applied to contra- and ipsilateral isthmotectal projections. The contralateral projection produced monosynaptic sinks in superficial layers and in layer 8. The results confirmed former findings obtained by single unit recordings. The ipsilateral projection elicited a prominent monosynaptic sink in layer 8. Recipient neurons were located in layers 6–7. These results, combined with those from the former intracellular study, led to the following neuronal circuit. Afferents from the ipsilateral NI inhibit non-efferent pear shaped neurons in the superficial layers, and strongly excite large ganglionic neurons projecting to the descending motor regions. Thus feedback to the output neurons strengthens the visually elicited responses.

scholarly journals Spatially distributed representation of taste quality in the gustatory insular cortex of awake behaving mice

2020 ◽  
Author(s):  
Ke Chen ◽  
Joshua F. Kogan ◽  
Alfredo Fontanini
Keyword(s):  
Spatial Organization ◽  
Spatial Clustering ◽  
Spatial Scales ◽  
Piriform Cortex ◽  
Insular Cortex ◽  
Multiple Spatial Scales ◽  
Somatosensory Cortices ◽  
Conflicting Evidence ◽  
Sensory Features ◽  
Spatially Distributed

SUMMARYVisual, auditory and somatosensory cortices are topographically organized, with neurons responding to similar sensory features clustering in adjacent portions of the cortex. Such topography has not been observed in the piriform cortex, whose responses to odorants are sparsely distributed across the cortex. The spatial organization of taste responses in the gustatory insular cortex (GC) is currently debated, with conflicting evidence from anesthetized rodents pointing to alternative and mutually exclusive models. Here, we rely on calcium imaging to determine how taste and task-related variables are represented in the superficial layers of GC of alert, licking mice. Our data show that the various stimuli evoke sparse responses from a combination of broadly and narrowly tuned neurons. Analysis of the distribution of responses over multiple spatial scales demonstrates that taste representations are distributed across the cortex, with no sign of spatial clustering or topography. Altogether, data presented here support the idea that the representation of taste qualities in GC of alert mice is sparse and distributed, analogous to the representation of odorants in piriform cortex.

scholarly journals BMP Signaling Interferes with Optic Chiasm Formation and Retinal Ganglion Cell Pathfinding in Zebrafish

2021 ◽  
Vol 22 (9) ◽  
pp. 4560
Author(s):  
Max D. Knickmeyer ◽  
Juan L. Mateo ◽  
Stephan Heermann
Keyword(s):  
Sensory Information ◽  
Optic Tract ◽  
Optic Chiasm ◽  
Contralateral Side ◽  
Bmp Signaling ◽  
The Body ◽  
Experimental Induction ◽  
Ligand Expression ◽  
Ipsilateral Projection ◽  
Contralateral Eye

Decussation of axonal tracts is an important hallmark of vertebrate neuroanatomy resulting in one brain hemisphere controlling the contralateral side of the body and also computing the sensory information originating from that respective side. Here, we show that BMP interferes with optic chiasm formation and RGC pathfinding in zebrafish. Experimental induction of BMP4 at 15 hpf results in a complete ipsilateral projection of RGC axons and failure of commissural connections of the forebrain, in part as the result of an interaction with shh signaling, transcriptional regulation of midline guidance cues and an affected optic stalk morphogenesis. Experimental induction of BMP4 at 24 hpf, resulting in only a mild repression of forebrain shh ligand expression but in a broad expression of pax2a in the diencephalon, does not per se prevent RGC axons from crossing the midline. It nevertheless shows severe pathologies of RGC projections e.g., the fasciculation of RGC axons with the ipsilateral optic tract resulting in the innervation of one tectum by two eyes or the projection of RGC axons in the direction of the contralateral eye.

scholarly journals Control of non-homeostatic feeding in sated mice using associative learning of contextual food cues

2018 ◽  
Author(s):  
Sarah A. Stern ◽  
Katherine R. Doerig ◽  
Estefania P. Azevedo ◽  
Elina Stoffel ◽  
Jeffrey M. Friedman
Keyword(s):  
Food Consumption ◽  
Food Availability ◽  
Molecular Mechanisms ◽  
Negative Reinforcement ◽  
Sensory Information ◽  
Insular Cortex ◽  
Brain Regions ◽  
Appetitive Conditioning ◽  
Functional Neuroanatomy ◽  
Intensive Training

ABSTRACTFeeding is a complex motivated behavior controlled by a distributed neural network that processes sensory information to generate adaptive behavioral responses. Accordingly, studies using appetitive Pavlovian conditioning confirm that environmental cues that are associated with food availability can induce feeding even in satiated subjects. However, in mice, appetitive conditioning generally requires intensive training and thus can impede molecular studies that often require large numbers of animals. To address this, we developed and validated a simple and rapid context-induced feeding (ctx-IF) task in which cues associated with food availability can later lead to increased food consumption in sated mice. We show that the associated increase in food consumption is driven by both positive and negative reinforcement and that spaced training is more effective than massed training. Ctx-IF can be completed in ∼1 week and provides an opportunity to study the molecular mechanisms and circuitry underlying non-homeostatic eating. We have used this paradigm to map brain regions that are activated during Ctx-IF with cFos immunohistochemistry and found that the insular cortex, and other regions, are activated following exposure to cues denoting the availability of food. Finally, we show that inhibition of the insular cortex using GABA agonists impairs performance of the task. Our findings provide a novel assay in mice for defining the functional neuroanatomy of appetitive conditioning and identify specific brain regions that are activated during the development of learned behaviors that impact food consumption.

scholarly journals Insula to mPFC reciprocal connectivity differentially underlies novel taste neophobic response and learning

2021 ◽  
Author(s):  
Haneen Kayyal ◽  
Sailendrakumar Kolatt Chandran ◽  
Adonis Yiannakas ◽  
Nathaniel Gould ◽  
Mohammad Khamaisy ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Sensory Information ◽  
Insular Cortex ◽  
Memory Formation ◽  
Intrinsic Properties ◽  
Insight Into ◽  
Taste Experience ◽  
Neophobic Response

To survive in an ever-changing environment, animals must detect and learn salient information. The anterior insular cortex (aIC) and medial prefrontal cortex (mPFC) are heavily implicated in salience and novelty processing, and specifically, the processing of taste sensory information. Here, we examined the role of aIC-mPFC reciprocal connectivity in novel taste neophobia and memory formation, in mice. Using pERK and neuronal intrinsic properties as markers for neuronal activation, and retrograde AAV (rAAV) constructs for connectivity, we demonstrate a correlation between aIC-mPFC activity and novel taste experience. Furthermore, by expressing inhibitory chemogenetic receptors in these projections, we show that aIC-to-mPFC activity is necessary for both taste neophobia and its attenuation. However, activity within mPFC-to-aIC projections is essential only for the neophobic reaction but not for the learning process. These results provide an insight into the cortical circuitry needed to detect, react to- and learn salient stimuli, a process critically involved in psychiatric disorders.

Birth dates of retinal ganglion cells giving rise to the crossed and uncrossed optic projections in the mouse

1985 ◽  
Vol 224 (1234) ◽  
pp. 57-77 ◽  
Keyword(s):  
Ganglion Cells ◽  
Tritiated Thymidine ◽  
Optic Tract ◽  
Peripheral Retina ◽  
Retinal Ganglion ◽  
Projection System ◽  
Contralateral Projection ◽  
Ipsilateral Projection ◽  
Bilateral Projection ◽  
Developmental Programme

In the mouse, as in most mammals, the crossed optic projections originate from the entire extent of the retina, whereas ganglion cells giving rise to the uncrossed (ipsilateral) projection are restricted to the temporal and ventral retina. The nasal border of this bilaterally projecting region in the retina corresponds to the midline of the visual field. Here the birth dates of ipsilaterally and contralaterally projecting ganglion cells were determined by combining tritiated thymidine labelling in the embryo with horseradish peroxidase tracings from the optic tract in the adult. Contralaterally projecting ganglion cells were found to be generated from embryonic day E11 to about E19 in a crude concentric fashion with the oldest cells in central and youngest ones in peripheral retina. Ipsilaterally projecting cells were born from E11 to E16, that is, during the earlier part of the period in which the contralateral projection was born. At the earliest time of ganglion cell generation (E11-12 ) ipsi- and contralaterally projecting cells were born within separate retinal regions, with the future midline representation forming the border between the two zones. This distinction became lost after E13, when both ipsi- and contralaterally projecting cells were born in the bilaterally projecting region. Hence at E11-12 the retina was found to have a bipartite organization that may allow the specification of the two maps of opposite topographical polarity in which the crossed and uncrossed projections are organized. Since in the adult retina this bipartite organization is preserved only in the large ganglion cells that project to the lateral geniculate nucleus, and since large ganglion cells are known to be the earliest ones formed in the mouse, these cells may be the ones that establish the early and bilateral projections of the retina. The conclusion that the bilateral projection system in the retina reflects an early developmental programme, and not the result of competition between the two eyes at later stages, was reinforced by observing a practically normal retinal origin of ipsilateral projections in mice which had only one normal eye from the earliest stages of eye development.

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