Barrel cortex function

“Two-photon calcium imaging in L2/3 of barrel cortex in vivo (Helmchen and Denk, 2005; Wallace et al., 2008; Grewe and Helmchen, 2009) has provided additional insights into the spatiotemporal aspects of population reponses.”

“This subcellular target structure specificity of the inhibitory neurons’ axon is the hallmark of many classifications and has been suggested to be independent of the laminar location of the cell body within a cortical column (Markram et al., 2004), but this view is far from unequivocal.”

“Particular potential is offered further by in vivo calcium imaging using genetically-encoded calcium indicators (GECIs) such as GCaMP-3 (Tian et al., 2009) or Yellow Cameleon 3.60 (Nagai et al., 2004; Lütcke et al., 2010).”

“From data obtained in cat visual cortex, Douglas and Martin defined a ‘canonical’ microcircuit of neocortex implying that most cortical areas have a rather similar basic neuronal network structure (Gilbert and Wiesel, 1983; Gilbert, 1983; Douglas and Martin, 1991, 2004).”

“…different molecules and their combinations, including oligopeptide co-transmitters, calcium binding proteins, and receptor subunits, suggesting a huge functional variability amongst cortical GABAergic neurons (Markram et al., 2004; Sugino et al., 2006; Ascoli et al., 2008; Taniguchi et al., 2011).”

“Knowledge about its development may contribute important aspects needed to understand its mechanisms of operation in the adult, both under physiological as well as pathophysiological conditions, such as neurodevelopmental disorders (for review Amaral et al., 2008; Courchesne et al., 2007).”

“The literature on neocortical GABAergic neurons is vast and many efforts have been made to describe their features and to characterize their synaptic connections (e.g. Ascoli et al., 2008).”

“Tactile information from individual whiskers is processed in single barrel columns in vS1 (Feldmeyer et al., 2013; Simons, 1978).”

“On the other hand, while this approach can provide an overview of connection likelihood and strength— bothwithin (Petersen and Sakmann, 2000) and between (Binzegger et al., 2004; Feldmeyer et al., 2013; Oberlaender et al., 2012) cortical layers and regions—such descriptions are often limited by their cellular and func…”

“We focused on the primary somatosensory barrel cortex (S1) of mice, which contains a remarkable map of the mystacial vibrissae such that each whisker is individually represented in a well-defined cortical barrel column (Petersen, 2007; Diamond et al., 2008; Feldmeyer et al., 2013).”

“, 2005) with extended shapes can be used to efficiently stimulate various cellular populations, including principal cells and different interneuron types, in cortical layer 2/3 and in layer 4, the main thalamorecipient lamina in sensory cortex (Feldmeyer et al., 2013).”

“The apparent absence of L4 in M1 and other agranular cortical areas has long been of interest for its implication that the circuit organization of these areas differs fundamentally from that of sensory areas (Shipp, 2005; Feldmeyer et al., 2013; Shipp et al., 2013; García-Cabezas and Barbas, 2014).”

“This type of well-defined structure is most clear in the rat barrel cortex (Lubke et al., 2000; Bureau et al., 2004; Feldmeyer et al., 2013) but Mountcastle and others have pointed out that although there are occasional discontinuities in physiological and anatomical properties, there is a diverse…”

“Although we will focus on a structurally and functionally well defined subregion of the somatosensory cortex, the barrel cortex (for review Petersen, 2007; Feldmeyer et al., 2013), we will also emphasize the role of subcortical structures and the motor system in the generation of activity patterns in the barrel cortex.”

“Layer 4 (L4) is the main input layer of the sensory cortex, which receives and pre-processes information from the thalamus and conveys it to other cortical layers (Petersen, 2007; Feldmeyer, 2012; Feldmeyer et al., 2013).”

“In addition, weak and delayed inhibition from 5HT3a neurons—in combination with the silencing of SST interneurons—might enable L2 Pyr neurons to be particularly sensitive to delayed and convergent input from other brain areas, such as M1 or S2, or ascending inputs within the column (Feldmeyer et al. 2013; Kinnischtzke…”

“In mice, tactile information received through deflections of whiskers is processed in the somatosensory barrel cortex (Diamond et al., 2008; Diamond & Arabzadeh, 2013; Feldmeyer et al., 2013).”

“Neurons in different layers are coupled through interlaminar connections which excite both excitatory neurons and inhibitory interneurons in the target layers (Lefort et al., 2009; Hooks et al., 2011; Feldmeyer et al., 2013; Pluta et al., 2015).”

“It is therefore considered to be a ‘‘higherorder’’ thalamic nucleus (Feldmeyer et al., 2013; Groh et al., 2014; Jouhanneau et al., 2014; Sherman, 2016).”

“though the cell types are purely defined by dendrite morphology, intrinsic properties (Feldmeyer et al., 2013), in vivo function (de Kock et al.”

“Yet these brainstem nuclei originate distinct pathways for somatosensory signals ascending to the cortex, with markedly different response properties (reviewed in: Bosman et al., 2011; Diamond et al., 2008; Feldmeyer et al., 2013; Kleinfeld andDeschênes, 2011).”

“Our sample comprises all previously reported dendritic cell types of excitatory neurons in rat vS1 (Feldmeyer et al. 2013).”

“To explore AIS plasticity in a behaviorally-relevant context, we utilized the mouse whisker-to-barrel system (Feldmeyer et al., 2013; Stuttgen and Schwarz, 2018).”

“VPM neurons receive ascending sensory information directly from the trigeminal brain stem nucleus and respond robustly to the deflection of a single whisker (Feldmeyer et al., 2013).”

“The mouse primary somatosensory barrel cortex (wS1) is an anatomically-defined brain region specialized in processing whisker sensory information (Woolsey and Van der Loos, 1970; Petersen, 2007; Diamond et al., 2008; Feldmeyer et al., 2013).”

“The paralemniscar pathway could play a major role in the PC, where L5st cells showed an overrepresentation of intracolumnar activity; at the same time, the lemniscar pathway could be responsible for propagating the intracolumnar synchronization horizontally—thus attributing different but complementary roles to both pa…”

“Although the formation and anatomical refinement of barrel cortex organization during development has been extensively studied (van der Loos and Woolsey 1973; Erzurumlu and Gaspar 2012; Feldmeyer et al. 2013), little is known about the corresponding functional changes, especially how whiskerevoked cortical activity de…”

“In this study, we investigated functional roles of VIP neurons in the primary whisker somatosensory barrel cortex (wS1), a cortical region important for processing whisker-related sensorimotor information inmice (Bosmanet al., 2011; Diamond et al., 2008; Feldmeyer et al., 2013; Petersen, 2019).”

“Furthermore, individual modalities develop progressively, as the critical periods of rodent somatosensory cortex begin at the subcortical level and then progress to cortical levels (Feldmeyer et al., 2013).”

“Cortical minicolumns (Mountcastle 1997) and the barrel cortex (Petersen 2007; Feldmeyer et al. 2013) are good examples.”

“The prevailing view of the barrel cortex is that it contains no cytoarchitectonic counterparts of barrels outside of L4 (Feldmeyer et al., 2013; Woolsey and Van der Loos, 1970).”

“In the primary somatosensory cortex, for example, neurons that project to the primary motor cortex and the secondary somatosensory cortex mostly do not overlap, suggesting potential subpopulations of Pyr neurons within supragranular IT types, on the basis of their projection specificity (Feldmeyer et al., 2013; Sato a…”

“J. Neurophysiol. 20, 408–434. Otsuka, T., and Kawaguchi, Y. (2008). Firing-Pattern-Dependent specificity of”

“…Lin, 1984; Dawson and Killackey, 1987; Welker et al., 1988; Fabri and Burton, 1991a) has made the rat barrel cortex a common model for anatomical and physiological investigations of sensory processing and brain plasticity (Petersen, 2007; Alloway, 2008; Wiest et al., 2008; Feldmeyer et al., 2013).”

“In contrast, much is known about the circuit connections and structure-function relationships in corresponding transcortical pathways in the whisker-barrel system of rats and mice (Feldmeyer, 2012; Feldmeyer et al., 2013; Petersen, 2019; Staiger and Petersen, 2020).”

“They do so by their mobile whiskers, which also sense the environment, obstacles , gaps, and different textures or objects (Diamond et al., 2008; Feldmeyer et al., 2013).”

“…cortex have since progressed toward defining the connections of morphologically and neurochemically distinct neuronal subpopulations in every layer and sublayer (Callaway, 2002; Thomson and Bannister, 2003; Bannister, 2005; Douglas and Martin, 2007; Briggs, 2010; Feldmeyer et al., 2013).”

“these neurons, as well as their functional diversity (Chen et al. 2013; Feldmeyer et al. 2013; Houweling and Brecht 2008; Oberlaender et al. 2012; Petersen and Crochet 2013; Sato and Svoboda 2010).”

“This could be caused by the rapid development of neocortical networks during the first weeks of life, including an increased synaptic connectivity between pyramidal neurons and a refinement of sensory maps, which results in an amplification of sensoryevoked depolarizing synaptic responses (Micheva and Beaulieu 1996; S…”

“Similar to L4SPs, which cluster around the dense terminal fields of VPM axons (Feldmeyer et al., 2013), we find that L6CCs cluster around the second innervation domain of VPM axons at the layer 5/6 border.”

“At this age a local, functionally defined lesion in the VPM blocks the whisker stimulationinduced cortical responses and also profoundly reduces the spontaneously occurring cortical burst activity [18], further demonstrating that the majority of the spontaneous spindle bursts in P0-P1 rat barrel cortex are generated i…”

“In the current study, we adopted a widely investigated somatosensory network involving multiple brain regions, such as the first-order ventral posterior thalamic nucleus, higherorder posterior medial thalamic nucleus (POm), primary somatosensory cortex (S1), secondary somatosensory cortex (S2), and primary motor corte…”

“…networks, which form the backbone of early intracortical processing of tactile sensory information (for review see Brecht, 2007; Petersen, 2007; Feldmeyer et al., 2013), we found (i) a reduced dendritic complexity of SpSt cells within the layer IV barrels, (ii) a decrease in the intracolumnar…”

“, cerebellum (Lalazar and Vaadia, 2008; Shadmehr and Krakauer, 2008) and sensory perception areas, such as primary sensory cortices (Matyas et al., 2010; Bastos et al., 2012; Feldmeyer et al., 2013)].”

“The rodent whisker system is an advantageous system to address this question (Brecht, 2007; Feldmeyer et al., 2013; Petersen, 2007).”

“…studies of layer 4 connections (Feldmeyer et al. 1999, 2005, 2006; Egger et al. 1999; Silver et al. 2003; Ramirez et al. 2014; for review see Feldmeyer et al. 2013), relatively little is known about the quantitative geometry of intracortical synaptic boutons terminating on L4 excitatory…”

“It comprises a multitude of 43 additional molecular, electrophysiological, and morphological parameters of single neurons in the somatosensory barrel cortex, a major cortical model system to study the development of neurons and their assembly into functional circuits (Feldmeyer et al. 2012).”

“are part of the lemniscal pathway, which is traditionally considered to carry exafferent sensory information (Feldmeyer et al., 2013).”

“ganizing principle in the otherwise disorganized reeler cortex (Mountcastle et al. 1955; Mountcastle 1957, 1997; Petersen and Sakmann 2001; Horton and Adams 2005; Feldmeyer et al. 2013).”

“…observed in thalamocortical pathways: in Fmr1-KO mice, enhanced NMDA/AMPA synaptic ratios and altered plasticity occur during the first but not by the end of the second postnatal week, indicating developmental delays within the neurotypical critical period for this pathway (Harlow et al., 2010).”

“The synaptic organization of the olfactory bulb includes structural and functional columns,(43,44) similar to the barrels or radial units of the neocortex.(45,46) Lateral synaptic connectivity within the olfactory bulb is much sparser.”

“Accordingly, whisker-related information is processed by highlyorganized neuronal circuits from the barrel-field primary somatosensory cortex (S1Bf) (Feldmeyer et al. 2013; Crochet et al. 2018).”

“These are relevant WM regions for the texture detection task in the light of the barrel cortex’s role in somatosensory information processing (for review see (Feldmeyer et al., 2013)).”

“…cortex, also known as the barrel cortex (BC) is a well-established model of cortical processing with an elegant cortical organization and high level of functional efficiency (Brecht et al., 1997; Petersen, 2007; Kleinfeld and Deschênes, 2011; Diamond and Arabzadeh, 2013; Feldmeyer et al., 2013).”

“Here, we focus on the mouse C2 barrel column, a region of primary somatosensory cortex involved in processing tactile information relating to the C2 whisker (Petersen 2007; Feldmeyer et al. 2013).”

“Multiple patch-clamp recordings in-vitro and in-vivo revealed a great diversity among cortical synapses with respect to their size, reliability, and temporal dynamics (reviewed by Lübke and Feldmeyer, 2007; Feldmeyer et al., 2013).”

“Rodents use their array of mystacial whiskers to obtain tactile information about their immediate facial surroundings (Brecht, 2007; Petersen, 2007; Diamond et al., 2008; Bosman et al., 2011; Feldmeyer et al., 2013).”

“The rodent whisker-system has become a popular model system for studying tactile information processing due to is neuroethological relevance (Feldmeyer et al., 2013; Petersen, 2007).”

“Sensory information in the mammalian cortex is processed in highly organized neuronal networks such as cortical columns[1,2].”

“4D, inset) and posteromedial nuclei, which are interconnected with S1 (Feldmeyer et al., 2013).”

“Work on the structure and physiology of neuronal circuits across the whisker pathway has accumulated at an accelerating pace (Feldmeyer et al., 2013; Fox, 2017).”