scholarly journals Layer and rhythm specificity for predictive routing

2020 ◽  
Author(s):  
André M. Bastos ◽  
Mikael Lundqvist ◽  
Ayan S. Waite ◽  
Nancy Kopell ◽  
Earl K. Miller
Keyword(s):  
Deep Layer ◽  
Predictive Coding ◽  
Superficial Layer ◽  
Field Potentials ◽  
Cortex Area ◽  
Cortical Hierarchy ◽  
Area 7A ◽  
Gamma Rhythms ◽  
Alpha Beta ◽  
High Beta

SummaryIn predictive coding, experience generates predictions that attenuate the feeding forward of predicted stimuli while passing forward unpredicted “errors”. Different models have different neural implementations of predictive coding. We recorded spikes and local field potentials from laminar electrodes in five cortical areas (V4, LIP, area 7A, FEF, and PFC) while monkeys performed a task that modulated visual stimulus predictability. Pre-stimulus predictions were associated with increased alpha/beta (8-30 Hz) power/coherence that fed back the cortical hierarchy primarily via deep-layer cortex. Unpredictable stimuli were associated with increases in spiking and in gamma-band (40-90 Hz) power/coherence that fed forward up the cortical hierarchy via superficial-layer cortex. Area 7A uniquely showed increases in high-beta (~22-28 Hz) power/coherence to unpredicted stimuli. These results suggest that predictive coding may be implemented via lower-frequency alpha/beta rhythms that “prepare” pathways processing predicted inputs by inhibiting feedforward gamma rhythms and associated spiking.

scholarly journals Layer and rhythm specificity for predictive routing

2020 ◽  
Vol 117 (49) ◽  
pp. 31459-31469 ◽  
Author(s):  
André M. Bastos ◽  
Mikael Lundqvist ◽  
Ayan S. Waite ◽  
Nancy Kopell ◽  
Earl K. Miller
Keyword(s):  
Predictive Coding ◽  
Superficial Layer ◽  
Frontal Eye Field ◽  
Beta Power ◽  
Deep Layers ◽  
Eye Field ◽  
Area 7A ◽  
Posterior Parietal ◽  
Alpha Beta ◽  
High Beta

In predictive coding, experience generates predictions that attenuate the feeding forward of predicted stimuli while passing forward unpredicted “errors.” Different models have suggested distinct cortical layers, and rhythms implement predictive coding. We recorded spikes and local field potentials from laminar electrodes in five cortical areas (visual area 4 [V4], lateral intraparietal [LIP], posterior parietal area 7A, frontal eye field [FEF], and prefrontal cortex [PFC]) while monkeys performed a task that modulated visual stimulus predictability. During predictable blocks, there was enhanced alpha (8 to 14 Hz) or beta (15 to 30 Hz) power in all areas during stimulus processing and prestimulus beta (15 to 30 Hz) functional connectivity in deep layers of PFC to the other areas. Unpredictable stimuli were associated with increases in spiking and in gamma-band (40 to 90 Hz) power/connectivity that fed forward up the cortical hierarchy via superficial-layer cortex. Power and spiking modulation by predictability was stimulus specific. Alpha/beta power in LIP, FEF, and PFC inhibited spiking in deep layers of V4. Area 7A uniquely showed increases in high-beta (∼22 to 28 Hz) power/connectivity to unpredictable stimuli. These results motivate a conceptual model, predictive routing. It suggests that predictive coding may be implemented via lower-frequency alpha/beta rhythms that “prepare” pathways processing-predicted inputs by inhibiting feedforward gamma rhythms and associated spiking.

scholarly journals Laminar recordings in frontal cortex suggest distinct layers for maintenance and control of working memory

2018 ◽  
Vol 115 (5) ◽  
pp. 1117-1122 ◽  
Author(s):  
André M. Bastos ◽  
Roman Loonis ◽  
Simon Kornblith ◽  
Mikael Lundqvist ◽  
Earl K. Miller
Keyword(s):  
Working Memory ◽  
Frontal Cortex ◽  
Superficial Layer ◽  
Field Potentials ◽  
Beta Band ◽  
Connectivity Patterns ◽  
Deep Layers ◽  
Alpha Beta ◽  
And Control ◽  
Laminar Specificity

All of the cerebral cortex has some degree of laminar organization. These different layers are composed of neurons with distinct connectivity patterns, embryonic origins, and molecular profiles. There are little data on the laminar specificity of cognitive functions in the frontal cortex, however. We recorded neuronal spiking/local field potentials (LFPs) using laminar probes in the frontal cortex (PMd, 8A, 8B, SMA/ACC, DLPFC, and VLPFC) of monkeys performing working memory (WM) tasks. LFP power in the gamma band (50–250 Hz) was strongest in superficial layers, and LFP power in the alpha/beta band (4–22 Hz) was strongest in deep layers. Memory delay activity, including spiking and stimulus-specific gamma bursting, was predominately in superficial layers. LFPs from superficial and deep layers were synchronized in the alpha/beta bands. This was primarily unidirectional, with alpha/beta bands in deep layers driving superficial layer activity. The phase of deep layer alpha/beta modulated superficial gamma bursting associated with WM encoding. Thus, alpha/beta rhythms in deep layers may regulate the superficial layer gamma bands and hence maintenance of the contents of WM.

scholarly journals Preservation and Changes in Oscillatory Dynamics across the Cortical Hierarchy

2020 ◽  
Vol 32 (10) ◽  
pp. 2024-2035 ◽  
Author(s):  
Mikael Lundqvist ◽  
André M. Bastos ◽  
Earl K. Miller
Keyword(s):  
Local Field ◽  
Local Field Potentials ◽  
Gamma Oscillations ◽  
Field Potentials ◽  
Oscillatory Dynamics ◽  
Cortical Areas ◽  
Cortical Hierarchy ◽  
Alpha Beta ◽  
Spiking Activity ◽  
Prefrontal Cortices

Theta (2–8 Hz), alpha (8–12 Hz), beta (12–35 Hz), and gamma (>35 Hz) rhythms are ubiquitous in the cortex. However, there is little understanding of whether they have similar properties and functions in different cortical areas because they have rarely been compared across them. We record neuronal spikes and local field potentials simultaneously at several levels of the cortical hierarchy in monkeys. Theta, alpha, beta, and gamma oscillations had similar relationships to spiking activity in visual, parietal, and prefrontal cortices. However, the frequencies in all bands increased up the cortical hierarchy. These results suggest that these rhythms have similar inhibitory and excitatory functions across the cortex. We discuss how the increase in frequencies up the cortical hierarchy may help sculpt cortical flow and processing.

scholarly journals Preservation and changes in oscillatory dynamics across the cortical hierarchy

2020 ◽  
Author(s):  
Mikael Lundqvist ◽  
André M. Bastos ◽  
Earl K. Miller
Keyword(s):  
Prefrontal Cortex ◽  
Local Field ◽  
Gamma Oscillations ◽  
Field Potentials ◽  
Phase Coupling ◽  
Oscillatory Dynamics ◽  
Cortical Areas ◽  
Gamma Frequency ◽  
Cortical Hierarchy ◽  
Alpha Beta

AbstractTheta (2-8 Hz), Alpha (8-12 Hz), beta (12-35 Hz) and gamma (>35 Hz) rhythms are ubiquitous in cortex. But there is little understanding of whether they have similar properties and functions in different cortical areas because they have rarely been compared across them. We record neuronal spikes and local field potentials simultaneously at several levels of the cortical hierarchy in monkeys. Theta, alpha, beta and gamma oscillations had similar relationships to spiking activity in visual, parietal and prefrontal cortex. However, the frequencies in all bands increased up the cortical hierarchy. These results suggest that these rhythms have similar functions inhibitory and excitatory across cortex. We discuss how the increase in frequencies up the cortical hierachy may help sculpt cortical flow and processing.Significance statementPhase-coupling in alpha/beta and gamma frequency ranges between cortical areas is often viewed as a means to shape brain-wide communication. However, systematic frequency differences between communicating areas are typically not considered, but equally important. Here we show that alpha/beta and gamma oscillations are of systematically higher frequency ascending the cortical hierarchy. This presents a fresh view on a widely studied topic. It has important implications in shaping cortical communication and helps explain widely observed phenomena.

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 Gross anatomy of the narial and labial musculatures of one humped Camel (Camelus dromedarius)

2016 ◽  
Vol 33 (04) ◽  
pp. 171-178
Author(s):  
Z. Adam ◽  
A. Awaad ◽  
M. Tawfiek ◽  
A. Ibrahim
Keyword(s):  
Deep Layer ◽  
Gross Anatomy ◽  
Middle Layer ◽  
Superficial Layer ◽  
Living Conditions ◽  
Camelus Dromedarius ◽  
Nerve Supply ◽  
Levator Labii Superioris ◽  
The One

Abstract Introduction: The objective of this study was to clarify the anatomy of the narial and labial musculatures of the one-humped camel (Camelus dromedarius) and their nerve supply. Materials and Methods: Sixteen head specimens from adult and symptomatically healthy camels of both sexes were used. The muscles of the nostrils and lips were carefully dissected and illustrated to demonstrate their origin, insertion and relations. The nerves in this area were also dissected to show their branches and distribution. Results: The dissection of these regions revealed that their muscles were arranged in three layers; the superficial layer included M. dilator naris apicalis, M. dilator naris medialis and M. levator nasolabialis, the middle layer was formed of maxillo-labial group of muscles (M. levator labii superioris, M. dilator naris lateralis and M. depressor labii superioris) and the deep layer was formed by M. lateralis nasi. Moreover, the lips had M. orbicularis oris, M. incisivus superioris, M. incisivus inferioris and M. mentalis, however, the M. depressor labii inferioris was absent in the animal under investigation. The muscles of nostrils and lips were innervated by N. trigeminus (V) and N. facialis (VII). Conclusion: The arrangement of the narial and labial muscles is unique and may relate to its living conditions of frequent sand-storms and direct sun rays, where the camel is the only domesticated animal known for its ability to close its nostril.

Differences in voltage-dependent sodium currents exhibited by superficial and deep layer neurons of guinea pig entorhinal cortex

1994 ◽  
Vol 71 (5) ◽  
pp. 1986-1991 ◽  
Author(s):  
S. Fan ◽  
M. Stewart ◽  
R. K. Wong
Keyword(s):  
Guinea Pig ◽  
Entorhinal Cortex ◽  
Deep Layer ◽  
Sodium Current ◽  
Membrane Conductance ◽  
Cell Voltage ◽  
Superficial Layer ◽  
Peak Amplitude ◽  
Sodium Currents ◽  
Test Pulse

1. Sodium currents were studied using whole-cell voltage-clamp techniques in neurons acutely isolated from superficial (II/III) and deep (V/VI) layers of guinea pig entorhinal cortex. 2. Sodium currents were larger (peak amplitude) in superficial than in deep layer cells under the same conditions: -1939 +/- 780 (SD) pA (N = 6) versus -307 +/- 257 pA (N = 6). Specific membrane conductance was calculated to be 12.3 +/- 9.6 mS/cm2 for superficial layer cells and 1.4 +/- 0.9 mS/cm2 for deep layer cells. 3. Sodium currents could be activated in superficial layer cells from potentials as depolarized as -20 mV, whereas no significant currents could be activated in deep neurons from potentials more depolarized than about -50 mV. Using a protocol consisting of a 25-ms prepulse and a 20 ms test pulse, the inactivation curves for superficial layer cells were found to be shifted toward more depolarized potentials by an average of 15 mV (V50 = -59.8 +/- 3.8 mV compared with -75.7 +/- 12.0 mV for deep cells). This produced a region of overlap with the activation curves for superficial cells. 4. Over a range of about -50 to -20 mV in superficial layer cells, the region of overlap of the activation and inactivation curves, a sodium current could be activated, which did not fully inactivate during the test pulse (average peak amplitude: -89.5 +/- 48.7 pA; crossover voltage: -39.2 +/- 2.0 mV). Voltage steps to more depolarized potentials, outside the voltage “window”, permitted complete inactivation of the sodium current.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Backwards is the way forward: Feedback in the cortical hierarchy predicts the expected future

2013 ◽  
Vol 36 (3) ◽  
pp. 221-221 ◽  
Author(s):  
Lars Muckli ◽  
Lucy S. Petro ◽  
Fraser W. Smith
Keyword(s):  
Predictive Coding ◽  
Internal Models ◽  
Prediction Errors ◽  
Conceptual Level ◽  
Cortical Hierarchy ◽  
The Brain ◽  
Descriptive Level ◽  
Perception Action ◽  
The Way

AbstractClark offers a powerful description of the brain as a prediction machine, which offers progress on two distinct levels. First, on an abstract conceptual level, it provides a unifying framework for perception, action, and cognition (including subdivisions such as attention, expectation, and imagination). Second, hierarchical prediction offers progress on a concrete descriptive level for testing and constraining conceptual elements and mechanisms of predictive coding models (estimation of predictions, prediction errors, and internal models).

The Micro-Mechanical Behavior of Articular Cartilage under Continuous Sliding Load

2013 ◽  
Vol 395-396 ◽  
pp. 654-657
Author(s):  
Peng Peng Xiao ◽  
Li Lan Gao ◽  
Zhi Dong Liu ◽  
Chun Qiu Zhang
Keyword(s):  
Articular Cartilage ◽  
Connective Tissue ◽  
Deep Layer ◽  
Compressive Strain ◽  
Middle Layer ◽  
Superficial Layer ◽  
Image Correlation ◽  
Daily Activities ◽  
Normal Displacement ◽  
Dic Technique

As a viscoelastic and nonlinear connective tissue, articular cartilage bears continuous sliding load in the daily activities. The optimized digital image correlation (DIC) technique was applied to investigate the effect of sliding rate and compressive strain on the normal displacement of different layers in pig articular cartilage under sliding load. The normal displacements of different layers in cartilage increase gradually with sliding going on with given sliding rate and compressive strain. Experiments showed that the normal displacement of superficial layer is the largest, the normal displacement of deep layer is the smallest and the normal displacement of middle layer is between superficial layer and deep layer, and found that the normal displacements of different layers in cartilage increase with increasing compressive strains, but decrease with increasing sliding rates. The normal displacement of different layers are different under continuous sliding load.

scholarly journals Urogenital fascia anatomy study in the inguinal region of 10 formalin-fixed cadavers: new understanding for laparoscopic inguinal hernia repair

BMC Surgery ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yi Li ◽  
Changfu Qin ◽  
Likun Yan ◽  
Cong Tong ◽  
Jian Qiu ◽  
...  
Keyword(s):  
Vas Deferens ◽  
Deep Layer ◽  
Superficial Layer ◽  
Laparoscopic Inguinal Hernia Repair ◽  
Inguinal Region ◽  
Hypogastric Plexus ◽  
Superior Hypogastric Plexus ◽  
Urogenital Fascia ◽  
Formalin Fixed ◽  
Deep Inguinal Ring

Abstract Purpose To investigate the urogenital fascia (UGF) anatomy in the inguinal region, to provide anatomical guidance for laparoscopic inguinal hernia repair (LIHR). Methods The anatomy was performed on 10 formalin-fixed cadavers. The peritoneum and its deeper fascial tissues were carefully dissected. Results The UGF’s bilateral superficial layer extended and ended in front of the abdominal aorta. At the posterior axillary line, the superficial layer medially reversed, with extension represented the UGF's deep layer. The UGF's bilateral deep layer medially extended beside the vertebral body and then continued with the transversalis fascia. The ureters, genital vessels, and superior hypogastric plexus moved between both layers. The vas deferens and spermatic vessels, ensheathed by both layers, moved through the deep inguinal ring. From the deep inguinal ring to the midline, the superficial layer extended to the urinary bladder’s posterior wall, whereas the deep layer extended to its anterior wall. Both layers ensheathed the urinary bladder and extended along the medial umbilical ligament to the umbilicus and in the sacral promontory, extended along the sacrum, forming the presacral fascia. The superficial layer formed the rectosacral fascia at S4 sacral vertebra, and the deep layer extended to the pelvic diaphragm, terminating at the levator ani muscle. Conclusion The UGF ensheaths the kidneys, ureters, vas deferens, genital vessels, superior hypogastric plexus, seminal vesicles, prostate, and urinary bladder. This knowledge of the UGF’s anatomy in the inguinal region will help find correct LIHR targets and reduce bleeding and other complications.

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