Neocortical Layer 1: An Elegant Solution to Top-Down and Bottom-Up Integration

Annual Review of Neuroscience, Journal Year: 2021, Volume and Issue: 44(1), P. 221 - 252

Published: March 17, 2021

Many of our daily activities, such as riding a bike to work or reading book in noisy cafe, and highly skilled professional playing tennis match violin concerto, depend upon the ability brain quickly make moment-to-moment adjustments behavior response results actions. Particularly, they neocortex integrate information provided by sensory organs (bottom-up information) with internally generated signals expectations attentional (top-down information). This integration occurs pyramidal cells (PCs) their long apical dendrite, which branches extensively into dendritic tuft layer 1 (L1). The outermost neocortex, L1 is conserved across cortical areas species. Importantly, predominant input for top-down information, relayed rich, dense mesh long-range projections that provide PCs. Here, we discuss recent progress understanding composition review evidence processing contributes functions perception, cross-modal integration, controlling states consciousness, attention, learning.

Language: Английский

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The regional variation of laminar thickness in the human isocortex is related to cortical hierarchy and interregional connectivity

PLoS Biology, Journal Year: 2023, Volume and Issue: 21(11), P. e3002365 - e3002365

Published: Nov. 9, 2023

The human isocortex consists of tangentially organized layers with unique cytoarchitectural properties. These show spatial variations in thickness and cytoarchitecture across the neocortex, which is thought to support function through enabling targeted corticocortical connections. Here, leveraging maps 6 cortical based on 3D brain histology, we aimed quantitatively characterize systematic covariation laminar structure cortex its functional consequences. After correcting for effect curvature, identified a pattern changes covariance from lateral frontal posterior occipital regions, differentiated dominance infra- versus supragranular layer thickness. Corresponding regularities connections along hierarchy, infragranular-dominant was associated higher hierarchical positions mapped resting-state effective connectivity humans tract-tracing structural macaques. Moreover, that regions similar patterns have likelihood strength In sum, here organization association cortico-cortical connectivity, illustrating how may provide foundational principle function.

Language: Английский

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Distributed context-dependent choice information in mouse posterior cortex

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Jan. 12, 2023

Abstract Choice information appears in multi-area brain networks mixed with sensory, motor, and cognitive variables. In the posterior cortex—traditionally implicated decision computations—the presence, strength, area specificity of choice signals are highly variable, limiting a cohesive understanding their computational significance. Examining mesoscale activity mouse cortex during visual task, we found that defined variable low-dimensional embedding space prominent contribution along ventral stream. Their subspace was near-orthogonal to concurrently represented sensory motor-related activations, modulations by task difficulty animals’ attention state. A recurrent neural network trained choices revealed an equivalent whose context-dependent dynamics agreed data. Our results demonstrated independent, cortex, controlled features demands, possibly linked contextual inference computations dynamic animal–environment interactions.

Language: Английский

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Motor cortex gates distractor stimulus encoding in sensory cortex

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: April 13, 2023

Suppressing responses to distractor stimuli is a fundamental cognitive function, essential for performing goal-directed tasks. A common framework the neuronal implementation of suppression attenuation from early sensory higher-order processing. However, details localization and mechanisms are poorly understood. We trained mice selectively respond target in one whisker field ignore opposite field. During expert task performance, optogenetic inhibition motor cortex increased overall tendency detection stimuli. Within cortex, enhanced propagation into target-preferring neurons. Single unit analyses revealed that (wMC) decorrelates stimulus encoding primary somatosensory (S1) neurons, which likely improves selective by downstream readers. Moreover, we observed proactive top-down modulation wMC S1, through differential activation putative excitatory inhibitory neurons before onset. Overall, our studies support contribution selection, suppressing behavioral gating within cortex.

Language: Английский

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Internal feedback in the cortical perception–action loop enables fast and accurate behavior

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(39)

Published: Sept. 22, 2023

Animals move smoothly and reliably in unpredictable environments. Models of sensorimotor control, drawing on control theory, have assumed that sensory information from the environment leads to actions, which then act back environment, creating a single, unidirectional perception–action loop. However, loop contains internal delays motor pathways, can lead unstable control. We show here these be compensated by feedback signals flow backward, toward areas. This is ubiquitous neural systems, we how compensates delays. accomplished filtering out self-generated other predictable changes so unpredicted, actionable rapidly transmitted action fastest components, effectively compressing input more efficiently use feedforward pathways: Tracts fast, giant neurons necessarily convey less accurate than tracts with many smaller neurons, but they are crucial for fast behavior. mathematically tractable model has an indispensable role achieving state estimation, localization function (how different parts cortex body), attention, all effective explain anatomical, physiological, behavioral observations, including visual cortex, heterogeneous kinetics receptors, presence cells humans as well patterns unexplained heterogeneity systems.

Language: Английский

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The locus coeruleus mediates behavioral flexibility

Cell Reports, Journal Year: 2022, Volume and Issue: 41(4), P. 111534 - 111534

Published: Oct. 1, 2022

Behavioral flexibility is the ability to adjust behavioral strategies in response changing environmental contingencies. A major hypothesis field posits that activity of neurons locus coeruleus (LC) plays an important role mediating flexibility. To test this hypothesis, we developed a tactile-based rule-shift detection task which mice responded left and right whisker deflections context-dependent manner exhibited varying degrees switching behavior. Recording spiking from optogenetically tagged LC at millisecond precision during performance revealed prominent graded correlation between baseline flexibility, where higher following rule change was associated with faster new rule. Increasing optogenetic activation accelerated improved performance. Overall, our study provides evidence reveal link

Language: Английский

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Ultrastructural sublaminar-specific diversity of excitatory synaptic boutons in layer 1 of the adult human temporal lobe neocortex

Published: Jan. 22, 2025

Layer (L)1, beside receiving massive cortico-cortical, commissural and associational projections, is the termination zone of tufted dendrites pyramidal neurons area Ca 2+ spike initiation. However, its synaptic organization in humans not known. Quantitative 3D-models boutons (SBs) L1 human temporal lobe neocortex were generated from non-epileptic neocortical biopsy tissue using transmission electron microscopy, 3D-volume reconstructions TEM tomography. Particularly, size active zones (AZs) readily releasable, recycling resting pool vesicles (SVs) quantified.The majority SBs contained numerous mitochondria comprising ∼7% total volume SBs, had a large macular, non-perforated AZs (∼0.20 µm 2 ) predominantly located on dendritic spines. ∼3500 SVs, comparably releasable (∼4 SVs), (∼470 SVs) (∼2900 pool. Astrocytic coverage suggests both cross talk or removal spilled glutamate by astrocytic processes at complexes.The structural composition may underlie function networks that mediate, integrate synchronize contextual cross-modal information, enabling flexible state-dependent processing feedforward sensory inputs other layers cortical column.

Language: Английский

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Age and Learning Shapes Sound Representations in Auditory Cortex During Adolescence

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 6, 2025

Summary Adolescence is a developmental period characterized by heightened plasticity, yet how ongoing development affects sensory processing and cognitive function unclear. We investigated adolescent (postnatal day 40 ± 2) adult 80 mice differ in performance on pure tone Go/NoGo auditory discrimination task of varying difficulty. Using dense electrophysiological recordings, we measured spiking activity at single neuron resolution the cortex while were engaged task. Adolescent showed lower compared to adults, particularly more challenging versions discrimination. This difference was due higher response variability weaker control expressed as bias. neuronal responses differed only slightly representations tones when outside context learning However, cortical after within markedly different. found differences stimulus- choice-related level representations, well population-level decoding adolescents. Overall, adolescents slower, especially for difficult sound discrimination, reflecting immature sounds choices. Notably, age-related differences, which learning, combined impact age learning. Our findings highlight distinct neurophysiological behavioral profiles adolescence, underscoring mechanisms plasticity during this sensitive period.

Language: Английский

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Age and Learning Shapes Sound Representations in Auditory Cortex During Adolescence

Published: March 31, 2025

Adolescence is a developmental period characterized by heightened plasticity, yet how ongoing development affects sensory processing and cognitive function unclear. We investigated adolescent (postnatal day 40 ± 2) adult 80 mice differ in performance on pure tone Go/NoGo auditory discrimination task of varying difficulty. Using dense electrophysiological recordings, we measured spiking activity at single neuron resolution the cortex while were engaged task. Adolescent showed lower compared to adults, particularly more challenging versions discrimination. This difference was due higher response variability weaker control expressed as bias. neuronal responses differed only slightly representations tones when outside context learning However, cortical after within markedly different. found differences stimulus- choice-related level representations, well population-level decoding adolescents. Overall, adolescents slower, especially for difficult sound discrimination, reflecting immature sounds choices. Notably, age-related differences, which learning, combined impact age learning. Our findings highlight distinct neurophysiological behavioral profiles adolescence, underscoring mechanisms plasticity during this sensitive period.

Language: Английский

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Age and Learning Shapes Sound Representations in Auditory Cortex During Adolescence

Published: March 31, 2025

Adolescence is a developmental period characterized by heightened plasticity, yet how ongoing development affects sensory processing and cognitive function unclear. We investigated adolescent (postnatal day 40 ± 2) adult 80 mice differ in performance on pure tone Go/NoGo auditory discrimination task of varying difficulty. Using dense electrophysiological recordings, we measured spiking activity at single neuron resolution the cortex while were engaged task. Adolescent showed lower compared to adults, particularly more challenging versions discrimination. This difference was due higher response variability weaker control expressed as bias. neuronal responses differed only slightly representations tones when outside context learning However, cortical after within markedly different. found differences stimulus- choice-related level representations, well population-level decoding adolescents. Overall, adolescents slower, especially for difficult sound discrimination, reflecting immature sounds choices. Notably, age-related differences, which learning, combined impact age learning. Our findings highlight distinct neurophysiological behavioral profiles adolescence, underscoring mechanisms plasticity during this sensitive period.

Language: Английский

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