scholarly journals Hierarchy in sensory processing reflected by innervation balance on cortical interneurons

2021 ◽  
Vol 7 (20) ◽  
pp. eabf5676
Author(s):  
Guofen Ma ◽  
Yanmei Liu ◽  
Lizhao Wang ◽  
Zhongyi Xiao ◽  
Kun Song ◽  
...  

Sensory processing is subjected to modulation by behavioral contexts that are often mediated by long-range inputs to cortical interneurons, but their selectivity to different types of interneurons remains largely unknown. Using rabies-virus tracing and optogenetics-assisted recording, we analyzed the long-range connections to various brain regions along the hierarchy of visual processing, including primary visual cortex, medial association cortices, and frontal cortices. We found that hierarchical corticocortical and thalamocortical connectivity is reflected by the relative weights of inputs to parvalbumin-positive (PV+) and vasoactive intestinal peptide–positive (VIP+) neurons within the conserved local circuit motif, with bottom-up and top-down inputs preferring PV+ and VIP+ neurons, respectively. Our algorithms based on innervation weights for these two types of local interneurons generated testable predictions of the hierarchical position of many brain areas. These results support the notion that preferential long-range inputs to specific local interneurons are essential for the hierarchical information flow in the brain.

2017 ◽  
Author(s):  
Michael Beyeler ◽  
Emily Rounds ◽  
Kristofor D. Carlson ◽  
Nikil Dutt ◽  
Jeffrey L. Krichmar

AbstractSupported by recent computational studies, sparse coding and dimensionality reduction are emerging as a ubiquitous coding strategy across brain regions and modalities, allowing neurons to achieve nonnegative sparse coding (NSC) by efficiently encoding high-dimensional stimulus spaces using a sparse and parts-based population code. Reducing the dimensionality of complex, multimodal sensory streams is critically important for metabolically constrained brain areas to represent the world. In this article, we provide an overview of NSC, summarize evidence for its role in neural computation in disparate regions of the brain, ranging from visual processing to spatial navigation, and speculate that specific forms of synaptic plasticity and homeostatic modulation may underlie its implementation. We suggest that NSC may be an organizing principle in the nervous system.


1998 ◽  
Vol 17 (3) ◽  
pp. 157-162 ◽  
Author(s):  
Maxine C Lintern ◽  
Janet R Wetherell ◽  
Margaret E Smith

1 In brain areas of untreated guinea-pigs the highest activity of acetylcholinesterase was seen in the striatum and cerebellum, followed by the midbrain, medulla-pons and cortex, and the lowest in the hippocampus. The activity in diaphragm was sevenfold lower than in the hippocampus. 2 At 1 h after soman (27 mg/kg) administration the activity of the enzyme was dramatically reduced in all tissues studied. In muscle the three major molecular forms (A12, G4 and G1) showed a similar degree of inhibition and a similar rate of recovery and the activity had returned to normal by 7 days. 3 In the brain soman inhibited the G4 form more than the G1 form. The hippocampus, cortex and midbrain showed the greatest reductions in enzyme activity. At 7 days the activity in the cortex, medulla pons and striatum had recovered but in the hippocampus, midbrain and cerebellum it was still inhibited. 4 Thus the effects of soman administration varied in severity and time course in the different tissues studied. However the enzyme activity was still reduced in all tissues at 24 h when the overt signs of poisoning had disappeared.


2019 ◽  
Vol 33 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Victor Schmidbauer ◽  
Silvia Bonelli

AbstractEpilepsy is frequently accompanied by severe cognitive side effects. Temporal lobe epilepsy (TLE), and even successful surgical treatment, may affect cognitive function, in particular language as well as verbal and visual memory function. Epilepsy arising from the temporal lobe can be controlled surgically in up to 70% of patients. The goals of epilepsy surgery are to remove the brain areas generating the seizures without causing or aggravating neuropsychological deficits. This requires accurate localization of the brain areas generating the seizures (“epileptogenic zone”) and the areas responsible for motor and cognitive functions, such as language and memory (“essential brain regions”) during presurgical evaluation. In the past decades, functional magnetic resonance imaging (fMRI) has been increasingly used to noninvasively lateralize and localize not only primary motor and somatosensory areas, but also brain areas that are involved in everyday language and memory processes. The imaging modality also shows potential for predicting the effects of temporal lobe resection on language and memory function. Together with other MRI modalities, cognitive fMRI is a promising tool to improve surgical strategies tailored to individual patients with regard to functional outcome, by virtue of definition of epileptic cerebral areas that need to be resected and eloquent areas that need to be spared.The aim of this review is to provide an overview of recent developments and practical recommendations for the clinical use of cognitive fMRI in TLE.


2020 ◽  
Author(s):  
Georg Hafner ◽  
Julien Guy ◽  
Mirko Witte ◽  
Pavel Truschow ◽  
Alina Rüppel ◽  
...  

Abstract The neocortex is composed of layers. Whether layers constitute an essential framework for the formation of functional circuits is not well understood. We investigated the brain-wide input connectivity of vasoactive intestinal polypeptide (VIP) expressing neurons in the reeler mouse. This mutant is characterized by a migration deficit of cortical neurons so that no layers are formed. Still, neurons retain their properties and reeler mice show little cognitive impairment. We focused on VIP neurons because they are known to receive strong long-range inputs and have a typical laminar bias toward upper layers. In reeler, these neurons are more dispersed across the cortex. We mapped the brain-wide inputs of VIP neurons in barrel cortex of wild-type and reeler mice with rabies virus tracing. Innervation by subcortical inputs was not altered in reeler, in contrast to the cortical circuitry. Numbers of long-range ipsilateral cortical inputs were reduced in reeler, while contralateral inputs were strongly increased. Reeler mice had more callosal projection neurons. Hence, the corpus callosum was larger in reeler as shown by structural imaging. We argue that, in the absence of cortical layers, circuits with subcortical structures are maintained but cortical neurons establish a different network that largely preserves cognitive functions.


eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Alex Tendler ◽  
Shlomo Wagner

Rhythmic activity in the theta range is thought to promote neuronal communication between brain regions. In this study, we performed chronic telemetric recordings in socially behaving rats to monitor electrophysiological activity in limbic brain regions linked to social behavior. Social encounters were associated with increased rhythmicity in the high theta range (7–10 Hz) that was proportional to the stimulus degree of novelty. This modulation of theta rhythmicity, which was specific for social stimuli, appeared to reflect a brain-state of social arousal. In contrast, the same network responded to a fearful stimulus by enhancement of rhythmicity in the low theta range (3–7 Hz). Moreover, theta rhythmicity showed different pattern of coherence between the distinct brain regions in response to social and fearful stimuli. We suggest that the two types of stimuli induce distinct arousal states that elicit different patterns of theta rhythmicity, which cause the same brain areas to communicate in different modes.


2019 ◽  
Vol 11 (2) ◽  
pp. 98
Author(s):  
Artur Jaschke

Music activates a wide array of brain areas involved in different functions such as   perception, processing and execution of music. Understanding musical processes in the brain has multiple implications in the neuro- and health sciences.  Challenging the brain with a multisensory stimulus such as music activates responses beyond the auditory cortex of the temporal lobe. Other areas that are involved include the frontal lobes, parietal lobes, areas of the limbic system such as the amygdala, hippocampus and thalamus, the cerebellum and the brainstem. Nonetheless, there has been no attempt to summarize all involved brain areas in music into one overall encompassing map. This may well be, as there has been no thorough theory introduced, which would allow an initial point of departure in creating such a mapTherefore, a thorough systematic review has been conducted to identify all mentioned neural connections involved in the perception, processing and execution of music.  Communication between the thalamic nuclei is the initial step in multisensory integration, which lies at the base of the neural networks as proposed in this paper. Against this background, this manuscript introduces the to our knowledge first map of all brain regions involved in the perception, processing and execution of music.Consequently, placing thalamic multisensory integration at the core of this atlas allowed us to create a preliminary theory to explain the complexity of music induced brain activation.


Author(s):  
Kübra Eroğlu ◽  
Temel Kayıkçıoğlu ◽  
Onur Osman

The aim of this study was to examine brightness effect, which is the perceptual property of visual stimuli, on brain responses obtained during visual processing of these stimuli. For this purpose, brain responses of the brain to changes in brightness were explored comparatively using different emotional images (pleasant, unpleasant and neutral) with different luminance levels. Moreover, electroencephalography recordings from 12 different electrode sites of 31 healthy participants were used. The power spectra obtained from the analysis of the recordings using short time Fourier transform were analyzed, and a statistical analysis was performed on features extracted from these power spectra. Statistical findings obtained from electrophysiological data were compared with those obtained from behavioral data. The results showed that the brightness of visual stimuli affected the power of brain responses depending on frequency, time and location. According to the statistically verified findings, the distinctive effect of brightness occurred in the parietal and occipital regions for all the three types of stimuli. Accordingly, the increase in the brightness of pleasant and neutral images increased the average power of responses in the parietal and occipital regions whereas the increase in the brightness of unpleasant images decreased the average power of responses in these regions. However, the increase in brightness for all the three types of stimuli reduced the average power of frontal and central region responses (except for 100-300 ms time window for unpleasant stimuli). The statistical results obtained for unpleasant images were found to be in accordance with the behavioral data. The results also revealed that the brightness of visual stimuli could be represented by changing the activity power of the brain cortex. The main contribution of this research was to comprehensively examine brightness effect on brain activity for images with different emotional content and different frequency bands at different time windows of visual processing for different brain regions. The findings emphasized that the brightness of visual stimuli should be viewed as an important parameter in studies using emotional image techniques such as image classification, emotion evaluation and neuro-marketing.


2020 ◽  
Author(s):  
Ernest Mas-Herrero ◽  
Larissa Maini ◽  
Guillaume Sescousse ◽  
Robert J. Zatorre

ABSTRACTNeuroimaging studies have shown that, despite the abstractness of music, it may mimic biologically rewarding stimuli (e.g. food) in its ability to engage the brain’s reward circuity. However, due to the lack of research comparing music and other types of reward, it is unclear to what extent the recruitment of reward-related structures overlaps among domains. To achieve this goal, we performed a coordinate-based meta-analysis of 38 neuroimaging studies (703 subjects) comparing the brain responses specifically to music and food-induced pleasure. Both engaged a common set of brain regions including the ventromedial prefrontal cortex, ventral striatum, and insula. Yet, comparative analyses indicated a partial dissociation in the engagement of the reward circuitry as a function of the type of reward, as well as additional reward type-specific activations in brain regions related to perception, sensory processing, and learning. These results support the idea that hedonic reactions rely on the engagement of a common reward network, yet through specific routes of access depending on the modality and nature of the reward.


2021 ◽  
Vol 9 ◽  
Author(s):  
AnnaCarolina Garza ◽  
Alice Aizza ◽  
Janchira K. Charoenworawat ◽  
Jessica A. Church

Your brain is always adjusting to the changing swirl of activities and interactions you have every day. Every time you accomplish a goal, you are exercising what are called the brain’s executive functions. These skills include resisting impulses, switching between tasks, and updating information in your memory. We asked whether these different skills relied on the same brain areas, and whether young people used the same brain areas as adults. We took pictures of kids’ and teens’ brains to see which areas of the brain they were using while they played three simple games related to these executive functions. We found that youth used similar brain regions to adults while playing the three games, and that many parts of the brain were used across all three games. These results help us understand how kids use their brains to be successful and how these skills develop.


2021 ◽  
Author(s):  
Adeeti Aggarwal ◽  
Connor Brennan ◽  
Jennifer Luo ◽  
Helen Chung ◽  
Diego Contreras ◽  
...  

Sensory processing is distributed among many brain regions that interact via feedforward and feedback signaling. It has been hypothesized that neuronal oscillations mediating feedforward and feedback interactions organize into travelling waves. However, stimulus evoked travelling waves of sufficient spatial scale have never been demonstrated directly. Here, we show that simple visual stimuli reliably evoke two traveling waves with spatial wavelengths that cover much of the cerebral hemisphere in awake mice. 30-50Hz feedforward waves arise in primary visual cortex (V1) and propagate rostrally, while 3-6Hz feedback waves originate in the association cortex and flow caudally. The phase of the feedback wave modulates the amplitude of the feedforward wave and synchronizes firing between V1 and parietal cortex. Altogether, these results provide direct experimental evidence that visual evoked travelling waves percolate through the cerebral cortex and coordinate neuronal activity across broadly distributed networks mediating visual processing.


Sign in / Sign up

Export Citation Format

Share Document