scholarly journals Pulvinar Modulates Synchrony across Visual Cortical Areas

Vision ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 22
Author(s):  
Nelson Cortes ◽  
Bruno O. F. de Souza ◽  
Christian Casanova
Keyword(s):  
Visual Cortex ◽  
Granger Causality ◽  
Gamma Oscillations ◽  
Oscillatory Activity ◽  
Area 17 ◽  
Feedback Processing ◽  
Area 21A ◽  
Layer I ◽  
Oscillatory Coupling ◽  
Visual Cortical

The cortical visual hierarchy communicates in different oscillatory ranges. While gamma waves influence the feedforward processing, alpha oscillations travel in the feedback direction. Little is known how this oscillatory cortical communication depends on an alternative route that involves the pulvinar nucleus of the thalamus. We investigated whether the oscillatory coupling between the primary visual cortex (area 17) and area 21a depends on the transthalamic pathway involving the pulvinar in cats. To that end, visual evoked responses were recorded in areas 17 and 21a before, during and after inactivation of the pulvinar. Local field potentials were analyzed with Wavelet and Granger causality tools to determine the oscillatory coupling between layers. The results indicate that cortical oscillatory activity was enhanced during pulvinar inactivation, in particular for area 21a. In area 17, alpha band responses were represented in layers II/III. In area 21a, gamma oscillations, except for layer I, were significantly increased, especially in layer IV. Granger causality showed that the pulvinar modulated the oscillatory information between areas 17 and 21a in gamma and alpha bands for the feedforward and feedback processing, respectively. Together, these findings indicate that the pulvinar is involved in the mechanisms underlying oscillatory communication along the visual cortex.

Subcortical projections to layer I of the visual cortex, area 17, of the rat

1981 ◽  
Vol 41 (2) ◽  
Author(s):  
J.G. Parnavelas ◽  
A. Chatzissavidou ◽  
R.A. Burne
Keyword(s):  
Visual Cortex ◽  
Area 17 ◽  
Cortex Area ◽  
Layer I

Termination of thalamic intralaminar nuclei afferents in visual cortex of squirrel monkey

1990 ◽  
Vol 5 (2) ◽  
pp. 151-154 ◽  
Author(s):  
Lex C. Towns ◽  
Johannes Tigges ◽  
Margarete Tigges
Keyword(s):  
Visual Cortex ◽  
Squirrel Monkey ◽  
Occipital Cortex ◽  
Area 17 ◽  
Intralaminar Nuclei ◽  
Layer I

AbstractThe projection of the thalamic intralaminar nuclei (ILN) upon the visual cortex in the squirrel monkey was studied using anterograde, autoradiographic techniques. In area 17, the ILN afferents terminate in the inner and outer portions of lamina V, whereas in areas 18 and 19 the fibers terminate more diffusely along the laminae V–VI boundary. Widespread labeling of layer I is seen throughout the occipital cortex.

scholarly journals Corticothalamic Projections Gate Alpha Rhythms in the Pulvinar

2021 ◽  
Vol 15 ◽  
Author(s):  
Nelson Cortes ◽  
Reza Abbas Farishta ◽  
Hugo J. Ladret ◽  
Christian Casanova
Keyword(s):  
Cortical Area ◽  
Hierarchical Level ◽  
Oscillatory Activity ◽  
Excitatory Postsynaptic Potential ◽  
Area 17 ◽  
Cortical Areas ◽  
Area 21A ◽  
Spiking Activity

Two types of corticothalamic (CT) terminals reach the pulvinar nucleus of the thalamus, and their distribution varies according to the hierarchical level of the cortical area they originate from. While type 2 terminals are more abundant at lower hierarchical levels, terminals from higher cortical areas mostly exhibit type 1 axons. Such terminals also evoke different excitatory postsynaptic potential dynamic profiles, presenting facilitation for type 1 and depression for type 2. As the pulvinar is involved in the oscillatory regulation between intercortical areas, fundamental questions about the role of these different terminal types in the neuronal communication throughout the cortical hierarchy are yielded. Our theoretical results support that the co-action of the two types of terminals produces different oscillatory rhythms in pulvinar neurons. More precisely, terminal types 1 and 2 produce alpha-band oscillations at a specific range of connectivity weights. Such oscillatory activity is generated by an unstable transition of the balanced state network’s properties that it is found between the quiescent state and the stable asynchronous spike response state. While CT projections from areas 17 and 21a are arranged in the model as the empirical proportion of terminal types 1 and 2, the actions of these two cortical connections are antagonistic. As area 17 generates low-band oscillatory activity, cortical area 21a shifts pulvinar responses to stable asynchronous spiking activity and vice versa when area 17 produces an asynchronous state. To further investigate such oscillatory effects through corticothalamo-cortical projections, the transthalamic pathway, we created a cortical feedforward network of two cortical areas, 17 and 21a, with CT connections to a pulvinar-like network with two cortico-recipient compartments. With this model, the transthalamic pathway propagates alpha waves from the pulvinar to area 21a. This oscillatory transfer ceases when reciprocal connections from area 21a reach the pulvinar, closing the CT loop. Taken together, results of our model suggest that the pulvinar shows a bi-stable spiking activity, oscillatory or regular asynchronous spiking, whose responses are gated by the different activation of cortico-pulvinar projections from lower to higher-order areas such as areas 17 and 21a.

scholarly journals Characterization of Feedback Neurons in the High-Level Visual Cortical Areas That Project Directly to the Primary Visual Cortex in the Cat

2021 ◽  
Vol 14 ◽  
Author(s):  
Huijun Pan ◽  
Shen Zhang ◽  
Deng Pan ◽  
Zheng Ye ◽  
Hao Yu ◽  
...  
Keyword(s):  
Information Processing ◽  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Information ◽  
Higher Order ◽  
Top Down ◽  
Cortical Areas ◽  
Area 21A ◽  
High Level ◽  
Visual Cortical

Previous studies indicate that top-down influence plays a critical role in visual information processing and perceptual detection. However, the substrate that carries top-down influence remains poorly understood. Using a combined technique of retrograde neuronal tracing and immunofluorescent double labeling, we characterized the distribution and cell type of feedback neurons in cat’s high-level visual cortical areas that send direct connections to the primary visual cortex (V1: area 17). Our results showed: (1) the high-level visual cortex of area 21a at the ventral stream and PMLS area at the dorsal stream have a similar proportion of feedback neurons back projecting to the V1 area, (2) the distribution of feedback neurons in the higher-order visual area 21a and PMLS was significantly denser than in the intermediate visual cortex of area 19 and 18, (3) feedback neurons in all observed high-level visual cortex were found in layer II–III, IV, V, and VI, with a higher proportion in layer II–III, V, and VI than in layer IV, and (4) most feedback neurons were CaMKII-positive excitatory neurons, and few of them were identified as inhibitory GABAergic neurons. These results may argue against the segregation of ventral and dorsal streams during visual information processing, and support “reverse hierarchy theory” or interactive model proposing that recurrent connections between V1 and higher-order visual areas constitute the functional circuits that mediate visual perception. Also, the corticocortical feedback neurons from high-level visual cortical areas to the V1 area are mostly excitatory in nature.

Visuomotor properties of corticotectal cells in area 17 and posteromedial lateral suprasylvian (PMLS) cortex of the cat

2001 ◽  
Vol 18 (1) ◽  
pp. 77-91 ◽  
Author(s):  
THEODORE G. WEYAND ◽  
ADELE C. GAFKA
Keyword(s):  
Eye Movements ◽  
Oculomotor System ◽  
Oscillatory Activity ◽  
Visual Response ◽  
Area 17 ◽  
Stimulus Motion ◽  
Velocity Amplitude ◽  
Cortical Areas ◽  
Saccade Velocity ◽  
Visual Cortical

We studied the visuomotor activity of corticotectal (CT) cells in two visual cortical areas [area 17 and the posteromedial lateral suprasylvian cortex (PMLS)] of the cat. The cats were trained in simple oculomotor tasks, and head position was fixed. Most CT cells in both cortical areas gave a vigorous discharge to a small stimulus used to control gaze when it fell within the retinotopically defined visual field. However, the vigor of the visual response did not predict latency to initiate a saccade, saccade velocity, amplitude, or even if a saccade would be made, minimizing any potential role these cells might have in premotor or attentional processes. Most CT cells in both areas were selective for direction of stimulus motion, and cells in PMLS showed a direction preference favoring motion away from points of central gaze. CT cells did not discharge with eye movements in the dark. During eye movements in the light, many CT cells in area 17 increased their activity. In contrast, cells in PMLS, including CT cells, were generally unresponsive during saccades. Paradoxically, cells in PMLS responded vigorously to stimuli moving at saccadic velocities, indicating that the oculomotor system suppresses visual activity elicited by moving the retina across an illuminated scene. Nearly all CT cells showed oscillatory activity in the frequency range of 20–90 Hz, especially in response to visual stimuli. However, this activity was capricious; strong oscillations in one trial could disappear in the next despite identical stimulus conditions. Although the CT cells in both of these regions share many characteristics, the direction anisotropy and the suppression of activity during eye movements which characterize the neurons in PMLS suggests that these two areas have different roles in facilitating perceptual/motor processes at the level of the superior colliculus.

Neurochemical compartmentation of monkey and human visual cortex: Similarities and variations in calbindin immunoreactivity across species

1993 ◽  
Vol 10 (6) ◽  
pp. 1109-1120 ◽  
Author(s):  
Stewart H. C. Hendry ◽  
Renee K. Carder
Keyword(s):  
Visual Cortex ◽  
Cortical Neurons ◽  
Calcium Binding ◽  
Squirrel Monkeys ◽  
Area 17 ◽  
Human Visual Cortex ◽  
Positive Elements ◽  
Large Numbers ◽  
Neurologically Normal ◽  
Visual Cortical

AbstractThe compartmental organization of visual cortical neurons was examined across species of primates by directly comparing the pattern of immunoreactivity for the 28-kD vitamin D-dependent calcium-binding protein (calbindin) in area 17 of squirrel monkeys, macaques, and neurologically normal adult humans. Area 17 of macaques and squirrel monkeys was similar in that somata and processes intensely immunoreactive for calbindin were present in the same layers (II-III, IVB, and V) and in both species formed a well-stained matrix that surrounded the CO-rich puffs in layer III. These intensely calbindin-immunoreactive neurons were identified as subpopulations of GABA-immunoreactive neurons. Among the most obvious differences in the two monkey species was the distribution of calbindin-positive elements outside of layer III: a dense immunostained matrix surrounded the puffs in layers II, IVB, V, and VI of squirrel monkeys but the immunostained neurons adopted no regular pattern outside layer III in macaques. In addition, although somata lightly immunoreactive for calbindin were present in both species, they were much more abundant in squirrel monkeys than macaques. The pattern of calbindin immunostaining in human area 17 resembled that of macaques in forming an intense matrix that surrounded puffs only in layer III, yet also resembled that of squirrel monkeys by including large numbers of lightly immunoreactive somata. These lightly immunostained somata included a very dense population forming a prominent band in layer IVA of human visual cortex. We conclude that for layer III of primary visual cortex, a similar pattern of neuronal chemistry exists across species of primates which is related to this layer's compartmental organization. Yet for other layers, the expression of calbindin immunoreactivity varies from one species to the next, perhaps reflecting variations in other neuronal properties.

scholarly journals Corticothalamic Projections Gate Alpha Rhythms in the Pulvinar

2021 ◽  
Author(s):  
Nelson Cortes ◽  
Reza Abbas Farishta ◽  
Hugo Ladret ◽  
Christian Casanova
Keyword(s):  
Cortical Area ◽  
Hierarchical Level ◽  
Oscillatory Activity ◽  
Excitatory Postsynaptic Potential ◽  
Area 17 ◽  
Cortical Areas ◽  
Area 21A ◽  
Spiking Activity

AbstractTwo types of corticothalamic (CT) terminals reach the pulvinar nucleus of the thalamus, and their distribution varies according to the hierarchical level of the cortical area they originate from. While type 2 terminals are more abundant at lower hierarchical levels, terminals from higher cortical areas mostly exhibit type 1 axons. Such terminals also evoke different excitatory postsynaptic potential dynamic profiles, presenting facilitation for type 1 and depression for type 2. As the pulvinar is involved in the oscillatory regulation between intercortical areas, fundamental questions about the role of these different terminal types in the neuronal communication throughout the cortical hierarchy are yielded. Our theoretical results support that the co-action of the two types of terminals produces different oscillatory rhythms in pulvinar neurons. More precisely, terminal types 1 and 2 produce alpha-band oscillations at a specific range of connectivity weights. Such oscillatory activity is generated by an unstable transition of the balanced state network’s properties that it is found between the quiescent state and the stable asynchronous spike response state. While CT projections from areas 17 and 21a are arranged in the model as the empirical proportion of terminals types 1 and 2, the actions of these two cortical connections are antagonistic. As area 17 generates low-band oscillatory activity, cortical area 21a shifts pulvinar responses to stable asynchronous spiking activity and vice-versa when area 17 produces an asynchronous state. To further investigate such oscillatory effects through corticothalamo-cortical projections, the transthalamic pathway, we created a cortical feedforward network of two cortical areas, 17 and 21a, with CT connections to a pulvinar-like network. With this model, the transthalamic pathway propagates alpha waves from the pulvinar to area 21a. This oscillatory transfer ceases when reciprocal connections from area 21a reach the pulvinar, closing the cortico-thalamic loop. Taken together, results of our model suggest that the pulvnar shows a bi-stable spiking activity, oscillatory or regular asynchronous spiking, whose responses are gated by the different activation of cortico-pulvinar projections from lower to higher-order areas such as areas 17 and 21a.

scholarly journals Visual cortex responds to transient sound changes without encoding complex auditory dynamics

2019 ◽  
Author(s):  
David Brang ◽  
John Plass ◽  
Aleksandra Sherman ◽  
William C. Stacey ◽  
Vibhangini S. Wasade ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Auditory Cortex ◽  
Visual Signals ◽  
Oscillatory Activity ◽  
Auditory Signal ◽  
Auditory Information ◽  
Fine Grained ◽  
Neural Origin ◽  
Environmental Events ◽  
Visual Cortical

Sounds enhance visual cortical sensitivity for co-occurring visual signals. Previous research has demonstrated that this facilitation occurs through crossmodal modulations of cortical oscillatory activity. However, the neural origin of these signals and auditory information conveyed by this mechanism remain poorly understood. Using intracranial electroencephalography (iEEG) in humans, we examined the sensitivity of visual cortex to three different forms of auditory information: rhythmic entrainment to sounds, auditory onset responses, and auditory offset responses. Subcortical auditory neurons exhibit frequency following behaviors in response to amplitude-modulated sounds, with oscillatory activity entrained at the rhythmic rate of the auditory signal. This auditory response is paralleled in the visual system by the entrainment of visual neurons to the rhythmic rate of flashing strobe lights. In contrast, ~20% of neurons in auditory cortex do not entrain to amplitude modulations but respond only to the onsets and/or offsets of auditory stimuli. In visual cortex, amplitude-modulated sounds elicited transient onset and offset responses in multiple areas, but no entrainment to the sounds’ modulations frequencies. These results suggest that auditory information conveyed to visual cortex does not include temporally fine-grained stimulus dynamics encoded by the auditory midbrain and thalamus but, rather, a temporally segmented representation of auditory events that emerges only in auditory cortex. Crossmodal responses were maximal in low-level visual cortex, potentially implicating a direct pathway for rapid interactions between low-to-mid-level auditory and visual cortices. This mechanism may facilitate perception by time-locking visual computations to environmental events marked by discontinuities in auditory input.

scholarly journals A causal role for the precuneus in network-wide theta and gamma oscillatory activity during complex memory retrieval

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Melissa Hebscher ◽  
Jed A Meltzer ◽  
Asaf Gilboa
Keyword(s):  
Memory Retrieval ◽  
Rest Period ◽  
Gamma Oscillations ◽  
Oscillatory Activity ◽  
Medial Temporal Lobes ◽  
Network Nodes ◽  
Temporal Lobes ◽  
Oscillatory Coupling ◽  
Phase Amplitude ◽  
Cortical Representations

Complex memory of personal events is thought to depend on coordinated reinstatement of cortical representations by the medial temporal lobes (MTL). MTL-cortical theta and gamma coupling is believed to mediate such coordination, but which cortical structures are critical for retrieval and how they influence oscillatory coupling is unclear. We used magnetoencephalography (MEG) combined with continuous theta burst stimulation (cTBS) to (i) clarify the roles of theta and gamma oscillations in network-wide communication during naturalistic memory retrieval, and (ii) understand the causal relationship between cortical network nodes and oscillatory communication. Retrieval was associated with MTL-posterior neocortical theta phase coupling and theta-gamma phase-amplitude coupling relative to a rest period. Precuneus cTBS altered MTL-neocortical communication by modulating theta and gamma oscillatory coupling. These findings provide a mechanistic account for MTL-cortical communication and demonstrate that the precuneus is a critical cortical node of oscillatory activity, coordinating cross-regional interactions that drive remembering.

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