Barrel cortex function

“…been identified in the rodent barrel cortex (Bayraktar et al., 2000; Porter et al., 2001; Angulo et al., 2003; Staiger et al., 2004; Ma et al., 2006; Sun et al., 2006; David et al., 2007; Tan et al., 2008; Karagiannis et al., 2009; Sun, 2009; Staiger et al., 2009; Helmstaedter et al., 2009a,b,c).”

“In the barrel column L4 spiny neurons target L5A pyramidal neurons (amongst projections to all other cortical layers; Feldmeyer et al., 2005; Schubert et al., 2006; Lefort et al., 2009), a projection that has not been identified for V1 (Fig.”

“and Brecht (2008). D.”

“Therefore, it is an ongoing experimental effort to find out which aspect of the multi-whisker response is due to integration on the ascending pathway and which one is generated by trans-columnar processing (Armstrong-James et al., 1991; Goldreich et al., 1999; Brecht and Sakmann, 2002a; Fox et al., 2003; Kwegyir-Afful…”

“1) (for reviews see Brecht, 2007; Lübke and Feldmeyer, 2007; Petersen, 2007; Schubert et al., 2007; Fox, 2008; Kanold and Luhmann, 2010).”

“…corticogenesis also controls programmed cell death (for review (Kilb et al., 2011), such as caspase-3 mediated apoptosis, by activating cell survival (e.g. neurotrophic factors) or cell death pathways (Golbs et al., 2011; Heck et al., 2008; Nimmervoll et al., 2012; Wagner-Golbs and Luhmann, 2012).”

“In the barrel column L4 spiny neurons target L5A pyramidal neurons (amongst projections to all other cortical layers; Feldmeyer et al., 2005; Schubert et al., 2006; Lefort et al., 2009), a projection that has not been identified for V1 (Fig.”

“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.”

“selectivity, and response adaptation (Minnery and Simons, 2003).”

“barrel cortex L5 neurons sending collaterals to POm (Hoogland et al., 1991; Bourassa et al., 1995; Veinante et al., 2000b; Killackey and Sherman, 2003), a higher thalamic nucleus which connects to several sensorimotor cortical areas (S1, S2, PM, M1, amongst”

“…of perceptual tasks that reflect specific characteristics of the conditioned stimulus (CS) in space and time (Disterhoft and Stuart, 1976; Kitzes et al., 1978; Diamond and Weinberger, 1986; Diamond and Weinberger, 1989; Recanzone et al., 1992, 1993; Schoups et al., 2001; Ghose et al., 2002).”

“The L5 projections to POm terminates in efficacious synapses showing strong short term depression (Groh et al., 2008).”

“Lateral to S1, we find the predominantly unimodal S2 (Menzel and Barth, 2005) which is oriented such that the face areas touch each other, followed more laterally by the again inverted body representation of the parietal-ventral area (PV) (Remple et al., 2003; Benison et al., 2007).”

“A current consensus is that trans-columnar processing plays generally a leading role in shaping excitatory and inhibitory parts of receptive fields (Moore and Nelson, 1998; Brecht and Sakmann, 2002a).”

“These diverse innervation types fall into just two functional classes, the slowly and the rapidly adapting afferents (SA and RA) (Gibson and Welker, 1983).”

“Together these strong inhibitory effects in L4 are thought to set a short window for synaptic integration by excitatory L4 cells (Brecht and Sakmann, 2002a; Pinto et al., 2003; Bruno and Sakmann, 2006; Wang et al., 2010).”

“Further, the supragranular signals are passed on by excitatory pathways mainly to L5 (cf. Kampa et al., 2006).”

“It contains the so-called ‘barreloids’ subdivided into a ‘head’, ‘core’, and ‘tail’ region relaying the different ascending pathways (Urbain and Deschênes, 2007; Furuta et al., 2009a).”

“barrel cortex L5 neurons sending collaterals to POm (Hoogland et al., 1991; Bourassa et al., 1995; Veinante et al., 2000b; Killackey and Sherman, 2003), a higher thalamic nucleus which connects to several sensorimotor cortical areas (S1, S2, PM, M1, amongst”

“Together, ACh-related effects may increase signal to noise ratio for behaviorally relevant signals (Gil et al., 1997; Oldford and CastroAlamancos, 2003; Gulledge and Stuart, 2005; Eggermann and Feldmeyer, 2009; Gulledge and Kawaguchi, 2007; Porter et al., 1999; Christophe et al., 2002).”

“These nuclei are subdivided in histologically defined zones, termed ‘barrelettes’, with each barrellette dedicated to represent predominantly one whisker and together forming a complete map of the whiskers (Ma and Woolsey, 1984; Henderson and Jacquin, 1995).”

“Septal columns refer to vertically aligned neurons above and below the septa in layer 4; they surround the barrels and separate them from each other (Alloway, 2008).”

“Two further groups developed early on a paradigm that is based on instrumental learning to test the whisker-related percept (Guic-Robles et al., 1989; Carvell and Simons, 1990; Guic-Robles et al., 1992).”

“review (Kilb et al., 2011), such as caspase-3 mediated apoptosis, by activating cell survival (e.”

“…(i.e. response reduction with repetitive whisker stimulation) is commonly observed in the cortex (Simons, 1978, 1985; Garabedian et al., 2003; Arabzadeh et al., 2003; Hartings et al., 2003; Webber and Stanley, 2004; Khatri et al., 2004; Stüttgen and Schwarz, 2010; Sanchez-Jimenez et al., 2009).”

“The caudal sector of the SpVi, the SpVic, contains numerous inhibitory neurons that exert inhibitory control on PrV, thus gating the flow of sensory information through this nucleus (Jacquin et al., 1989a,b; Timofeeva et al., 2004).”

“Harris et al. (1999) first trained single-whisker animals to cross a gap using the whisker and then cut the trained whisker and reglued it to the same or neighboring whisker stubs.”

“…been identified in the rodent barrel cortex (Bayraktar et al., 2000; Porter et al., 2001; Angulo et al., 2003; Staiger et al., 2004; Ma et al., 2006; Sun et al., 2006; David et al., 2007; Tan et al., 2008; Karagiannis et al., 2009; Sun, 2009; Staiger et al., 2009; Helmstaedter et al., 2009a,b,c).”

“…been identified in the rodent barrel cortex (Bayraktar et al., 2000; Porter et al., 2001; Angulo et al., 2003; Staiger et al., 2004; Ma et al., 2006; Sun et al., 2006; David et al., 2007; Tan et al., 2008; Karagiannis et al., 2009; Sun, 2009; Staiger et al., 2009; Helmstaedter et al., 2009a,b,c).”

“During whisking POm could thereby switch to the regular firing mode and reliably transmit signals between S1, S2, and M1 (Trageser et al., 2006; Trageser and Keller, 2004; Urbain and Deschênes, 2007) (Fig.”

“The best studied synaptic connections involving inhibitory neurons are the ones between fast-spiking L4 inhibitory neurons and L4 spiny neurons and L2/3 inhibitory neurons (Sun et al., 2006; Helmstaedter et al., 2008, 2009a, 2009b, 2009c).”

“The termination of barrel columns projections outside the whisker-related barrel field are found in a clustered fashion in rat S2 (Koralek et al., 1990; Zhang and Deschênes, 1998; Kim and Ebner, 1999; Chakrabarti and Alloway, 2006).”

“Furthermore, the horizontal spread of the sensory response has been observed to be decreased (Hentschke et al., 2006; Ferezou et al., 2006) (Fig.”

“…(Lendvai et al., 2000; Maravall et al., 2004a), or pruning of thalamocortical axons in their final termination area in L4 of a single barrel (Bender et al., 2003; Harris and Woolsey, 1983; Lübke et al., 2000; Schubert et al., 2003; Staiger et al., 2004) are still prominent and are strongly…”

“However, relating response patterns to the neuron type by juxtacellular recordings and subsequent neuronal reconstruction (de Kock et al., 2007; de Kock and Sakmann, 2008) confirmed layerspecific delays of transient responses but showed clear deviation from what would be expected from the known…”

“…the multi-whisker response is due to integration on the ascending pathway and which one is generated by trans-columnar processing (Armstrong-James et al., 1991; Goldreich et al., 1999; Brecht and Sakmann, 2002a; Fox et al., 2003; Kwegyir-Afful et al., 2005; Katz et al., 2006; Wright and Fox, 2010).”

“Together, ACh-related effects may increase signal to noise ratio for behaviorally relevant signals (Gil et al., 1997; Oldford and CastroAlamancos, 2003; Gulledge and Stuart, 2005; Eggermann and Feldmeyer, 2009; Gulledge and Kawaguchi, 2007; Porter et al., 1999; Christophe et al., 2002).”

“…by paired recordings – appears to be present: Bipolar-bitufted VIP cells, numerous in L2/3, sample signals from local pyramidal neurons (Porter et al., 1998; Reyes et al., 1998; Rozov et al., 2001) and target L5 pyramidal cells with their rich columnar axons (Bayraktar et al., 2000) (Fig.”

“The subsequent formation of early cortical circuits, however, is in many aspects regulated by spontaneous and periphery-driven neuronal activity and by the influence of neuromodulatory systems (Khazipov and Luhmann, 2006; Allene and Cossart, 2010).”

“…inhibition of pyramidal cells by intervening Martinotti cells (Silberberg and Markram, 2007; Berger et al., 2009; Murayama et al., 2009), the second is the preferential innervation of L6 inhibitory neurons by corticothalamic pyramidal cells (West et al., 2006; see also Kumar and Ohana, 2008).”

“The termination of barrel columns projections outside the whisker-related barrel field are found in a clustered fashion in rat S2 (Koralek et al., 1990; Zhang and Deschênes, 1998; Kim and Ebner, 1999; Chakrabarti and Alloway, 2006).”

“areas (Sato and Svoboda, 2010; see also results on heterogeneity in M1 by Huber et al., 2012).”

“…restructuring on a fine scale, e.g. higher-order branching of basal dendrites in L2/3 neurons and dendritic spine motility (Lendvai et al., 2000; Maravall et al., 2004a), or pruning of thalamocortical axons in their final termination area in L4 of a single barrel (Bender et al., 2003; Harris…”

“…been identified in the rodent barrel cortex (Bayraktar et al., 2000; Porter et al., 2001; Angulo et al., 2003; Staiger et al., 2004; Ma et al., 2006; Sun et al., 2006; David et al., 2007; Tan et al., 2008; Karagiannis et al., 2009; Sun, 2009; Staiger et al., 2009; Helmstaedter et al., 2009a,b,c).”

“…period suppresses tactile inputs following at a short interval fitting the notion of a fine balance between excitatory and inhibitory signal flows (Simons, 1978, 1985; Carvell and Simons, 1988; Simons et al., 1992; Webber and Stanley, 2004; Stüttgen and Schwarz, 2008; Crochet et al., 2011).”

“The barrel-related horizontal projection system originates mainly from supra- and infragranular layers and shows relatively short projection range inside S1 (a few axonal projections from L4 neurons to adjacent barrel columns do exist as well; see Staiger et al., 2004; Egger et al., 2008).”

“At P0, this cholinergic input is confined to the cortical subplate (Hanganu and Luhmann, 2004; Dupont et al., 2006; Hanganu et al., 2009), where it causes a pronounced excitation and burst firing of subplate cells (for reviews see Luhmann et al., 2009; Kanold and Luhmann, 2010) (Fig.”

“The first is the disynaptic inhibition of pyramidal cells by intervening Martinotti cells (Silberberg and Markram, 2007; Berger et al., 2009; Murayama et al., 2009), the second is the preferential innervation of L6 inhibitory neurons by corticothalamic pyramidal cells (West et al., 2006; see also…”

“…rabbit V1, S1 and M1 – identified by the waveform of their spike, the firing patterns and projection targets – clearly point to the notion that the essence of inhibitory circuits making up neocortical circuitry are likely to be captured by a similar strategy (Swadlow, 1988, 1989, 1990, 1991, 1994).”

“…well characterized in V1 (Bolz et al., 1989; Stratford et al., 1996; TarczyHornoch et al., 1999) but has not been characterized in the barrel column (Lefort et al., 2009; but see Zhang and Deschênes, 1997; Kumar and Ohana, 2008; Pichon et al., 2012, who show terminal endings of L6 axons in L4).”

“At P0, this cholinergic input is confined to the cortical subplate (Hanganu and Luhmann, 2004; Dupont et al., 2006; Hanganu et al., 2009), where it causes a pronounced excitation and burst firing of subplate cells (for reviews see Luhmann et al., 2009; Kanold and Luhmann, 2010) (Fig.”

“With further development and in rodents until the end of the first postnatal week, cholinergic fibers have innervated all cortical layers (Mechawar and Descarries, 2001) (Fig.”

“Sensory cortices seem to contribute to perception because they undergo plastic changes during learning of perceptual tasks that reflect specific characteristics of the conditioned stimulus (CS) in space and time (Disterhoft and Stuart, 1976; Kitzes et al., 1978; Diamond and Weinberger, 1986; Diamond and Weinberger, 19…”

“functional plasticity in the mature columnar network (Ego-Stengel et al., 2001; Ramanathan et al., 2009).”

“…the multi-whisker response is due to integration on the ascending pathway and which one is generated by trans-columnar processing (Armstrong-James et al., 1991; Goldreich et al., 1999; Brecht and Sakmann, 2002a; Fox et al., 2003; Kwegyir-Afful et al., 2005; Katz et al., 2006; Wright and Fox, 2010).”

“(Kremer et al., 2011).”

“…rabbit V1, S1 and M1 – identified by the waveform of their spike, the firing patterns and projection targets – clearly point to the notion that the essence of inhibitory circuits making up neocortical circuitry are likely to be captured by a similar strategy (Swadlow, 1988, 1989, 1990, 1991, 1994).”

“…in VPM to L4, basal L3, L5B, and 6A of the barrel columns (Henderson and Jacquin, 1995; Lo et al., 1999) while the second lemniscal path starts from PrV multi-whisker cells and is relayed via the head of barreloids in VPM to septal columns (Veinante and Deschênes, 1999; Furuta et al., 2009b).”

“scheme of ‘canonical’ microcircuitry have to be interpreted cautiously in the absence of a full connectionist cortical model (Markram, 2006; Helmstaedter et al., 2007), as columnar dynamics have been shown to deviate from the sequence expected from the microcircuit known so far.”

“…restructuring on a fine scale, e.g. higher-order branching of basal dendrites in L2/3 neurons and dendritic spine motility (Lendvai et al., 2000; Maravall et al., 2004a), or pruning of thalamocortical axons in their final termination area in L4 of a single barrel (Bender et al., 2003; Harris…”

“…the multi-whisker response is due to integration on the ascending pathway and which one is generated by trans-columnar processing (Armstrong-James et al., 1991; Goldreich et al., 1999; Brecht and Sakmann, 2002a; Fox et al., 2003; Kwegyir-Afful et al., 2005; Katz et al., 2006; Wright and Fox, 2010).”

“8A–C) (Crandall et al., 1986; Alloway et al., 2004; Chakrabarti et al., 2008).”

“At the same time the number of glutamatergic synaptic connections increases dramatically and become more reliable and efficacious (Frick et al., 2007; Feldmeyer and Radnikow, 2009).”

“The SpVic is itself under the inhibitory control of the caudalis nucleus of the trigeminal complex (SpVc) which increases sensory traffic through PrV by dis-inhibiting it from the inhibitory drive of the SpVic (Furuta et al., 2010).”

“The caudal sector of the SpVi, the SpVic, contains numerous inhibitory neurons that exert inhibitory control on PrV, thus gating the flow of sensory information through this nucleus (Jacquin et al., 1989a,b; Timofeeva et al., 2004).”

“There are cells that respond just to one whisker (mono-whisker cells) (Henderson and Jacquin, 1995; Lo et al., 1999) and others that integrate across whiskers (multi-whisker cells) (Jacquin and Rhoades, 1990; Veinante and Deschênes, 1999; Veinante et al., 2000a; Minnery and Simons, 2003).”

“As expected it is shaped by intracortical inhibition (Moore and Nelson, 1998; Butovas et al., 2006), but there is also considerable evidence that short term dynamics of thalamocortical (and possibly also intracortical) synapses play a role (Castro-”

“Using a frequency discrimination task in head-fixed rats, Gerdjikov et al. (2010) found that rats discriminate pulsatile stimulus frequencies between 60 and 90 Hz by integrating the vibrotactile signals rather than using frequency and kinematic cues (i.e. the pulse waveform).”

“…2000; Maravall et al., 2004a), or pruning of thalamocortical axons in their final termination area in L4 of a single barrel (Bender et al., 2003; Harris and Woolsey, 1983; Lübke et al., 2000; Schubert et al., 2003; Staiger et al., 2004) are still prominent and are strongly affected by whisker…”

“A reverse tendency exists for the projection from L6 to L4, which is functionally well characterized in V1 (Bolz et al., 1989; Stratford et al., 1996; TarczyHornoch et al., 1999) but has not been characterized in the barrel column (Lefort et al., 2009; but see Zhang and Deschênes, 1997; Kumar and…”

“Acetylcholine release is crucial for the emergence of the barrel pattern in immature neocortex (Zhu and Waite, 1998; Zhu et al., 2002) and keeps an important role for experience-dependent”

“This columncentered (and therefore microscopic) approach is likely reasonable as it has been shown that detection and discrimination of tactile stimuli are blocked by disturbing the integrity of just the barrel column (O’Connor et al., 2010a; Miyashita and Feldman, 2012).”

“Activation of barrel cortex follows a laminar pattern (Armstrong-James et al., 1992; Welker et al., 1993; Celikel et al., 2004).”

“…been identified in the rodent barrel cortex (Bayraktar et al., 2000; Porter et al., 2001; Angulo et al., 2003; Staiger et al., 2004; Ma et al., 2006; Sun et al., 2006; David et al., 2007; Tan et al., 2008; Karagiannis et al., 2009; Sun, 2009; Staiger et al., 2009; Helmstaedter et al., 2009a,b,c).”

“…been identified in the rodent barrel cortex (Bayraktar et al., 2000; Porter et al., 2001; Angulo et al., 2003; Staiger et al., 2004; Ma et al., 2006; Sun et al., 2006; David et al., 2007; Tan et al., 2008; Karagiannis et al., 2009; Sun, 2009; Staiger et al., 2009; Helmstaedter et al., 2009a,b,c).”

“Furthermore, neuronal activity evoked by electrical microstimulation (Butovas and Schwarz, 2007), optogenetic stimulation (Huber et al., 2008) and even juxtacellular stimulation of single neurons (Houweling and Brecht, 2008) in V1 and barrel cortex are perceived by rodents.”

“(PV) (Remple et al., 2003; Benison et al., 2007).”

“One causal factor for reduction and decorrelation of firing appears to be the upregulation of K channel expression and the concomitant decrement of input resistance of pyramidal cells (Kang et al., 1996; Maravall et al., 2004b; Waters and Helmchen, 2006; Golshani et al., 2009).”

“Map plasticity after sensory deprivation (for review see Feldman and Brecht, 2005), and during learning (e.g. Galvez et al., 2006) have been studied extensively and lead to functional readjustments of the microcircuits throughout life.”

“Acetylcholine release is crucial for the emergence of the barrel pattern in immature neocortex (Zhu and Waite, 1998; Zhu et al., 2002) and keeps an important role for experience-dependent functional plasticity in the mature columnar network (Ego-Stengel et al., 2001; Ramanathan et al., 2009).”

“…corticogenesis also controls programmed cell death (for review (Kilb et al., 2011), such as caspase-3 mediated apoptosis, by activating cell survival (e.g. neurotrophic factors) or cell death pathways (Golbs et al., 2011; Heck et al., 2008; Nimmervoll et al., 2012; Wagner-Golbs and Luhmann, 2012).”

“At the same time the number of glutamatergic synaptic connections increases dramatically and become more reliable and efficacious (Frick et al., 2007; Feldmeyer and Radnikow, 2009).”

“…been identified in the rodent barrel cortex (Bayraktar et al., 2000; Porter et al., 2001; Angulo et al., 2003; Staiger et al., 2004; Ma et al., 2006; Sun et al., 2006; David et al., 2007; Tan et al., 2008; Karagiannis et al., 2009; Sun, 2009; Staiger et al., 2009; Helmstaedter et al., 2009a,b,c).”

“Horizontal connections in barrel cortex are highly anisotropic showing a clear preference to run along rows rather than arcs of whiskers (Kim and Ebner, 1999; Petersen et al., 2003a; Bruno et al., 2009).”

“Furthermore, as in V1, a thalamo–cortico–thalamic feedback loop exists in which the two major thalamorecipient layers (L4 and L6A) are interconnected and report the cortical state of activity back to the thalamus (Zhang and Deschênes, 1997; Thomson, 2010; Briggs, 2010) (Fig.”

“…rabbit V1, S1 and M1 – identified by the waveform of their spike, the firing patterns and projection targets – clearly point to the notion that the essence of inhibitory circuits making up neocortical circuitry are likely to be captured by a similar strategy (Swadlow, 1988, 1989, 1990, 1991, 1994).”

“C) (Crandall et al., 1986; Alloway et al., 2004; Chakrabarti et al., 2008).”

“…been identified in the rodent barrel cortex (Bayraktar et al., 2000; Porter et al., 2001; Angulo et al., 2003; Staiger et al., 2004; Ma et al., 2006; Sun et al., 2006; David et al., 2007; Tan et al., 2008; Karagiannis et al., 2009; Sun, 2009; Staiger et al., 2009; Helmstaedter et al., 2009a,b,c).”

“These conclusions, however, have to be reevaluated in light of the consistent finding from cytometric and molecular analyses that motor cortex does show a small, but functional L4 (Skoglund et al., 1997; Rowell et al., 2010).”

“acetylcholine (ACh), norepinephrine (NE), and other neurotransmitters which act in thalamus and cortex amongst other structures (McCormick and Bal, 1997; Buzsaki et al., 1988; Kristt, 1979; Kristt and Waldman, 1981; Houser et al., 1985).”

“Amongst the most promising cellular tools are intracellular and juxtacellular recording/stimulation in vivo (Houweling et al., 2010; de Kock and Sakmann, 2008) which allows functional assessment together with complete morphological reconstruction of the neuron.”

“There are cells that respond just to one whisker (mono-whisker cells) (Henderson and Jacquin, 1995; Lo et al., 1999) and others that integrate across whiskers (multi-whisker cells) (Jacquin and Rhoades, 1990; Veinante and Deschênes, 1999; Veinante et al.”

“Another study found that L4 receptive field changes following manipulation of receptive field size on the level of TN, can be largely explained by this sub-cortical manipulation, and thus, argues against a dominant trans-columnar effect (Kwegyir-Afful et al., 2005).”

“These conclusions, however, have to be reevaluated in light of the consistent finding from cytometric and molecular analyses that motor cortex does show a small, but functional L4 (Skoglund et al., 1997; Rowell et al., 2010).”

“Lateral to S1, we find the predominantly unimodal S2 (Menzel and Barth, 2005) which is oriented such that the face areas touch each other, followed more laterally by the again inverted body representation of the parietal-ventral area (PV) (Remple et al., 2003; Benison et al., 2007).”

“…(i.e. response reduction with repetitive whisker stimulation) is commonly observed in the cortex (Simons, 1978, 1985; Garabedian et al., 2003; Arabzadeh et al., 2003; Hartings et al., 2003; Webber and Stanley, 2004; Khatri et al., 2004; Stüttgen and Schwarz, 2010; Sanchez-Jimenez et al., 2009).”

“The SpVic is itself under the inhibitory control of the caudalis nucleus of the trigeminal complex (SpVc) which increases sensory traffic through PrV by dis-inhibiting it from the inhibitory drive of the SpVic (Furuta et al., 2010).”

“…several different types of inhibitory neurons have also been identified in the rodent barrel cortex (Bayraktar et al., 2000; Porter et al., 2001; Angulo et al., 2003; Staiger et al., 2004; Ma et al., 2006; Sun et al., 2006; David et al., 2007; Tan et al., 2008; Karagiannis et al., 2009; Sun,…”

“…period suppresses tactile inputs following at a short interval fitting the notion of a fine balance between excitatory and inhibitory signal flows (Simons, 1978, 1985; Carvell and Simons, 1988; Simons et al., 1992; Webber and Stanley, 2004; Stüttgen and Schwarz, 2008; Crochet et al., 2011).”

“The first lemniscal system departs from mono-whisker neurons in PrV, and is relayed via the barreloid cores in VPM to L4, basal L3, L5B, and 6A of the barrel columns (Henderson and Jacquin, 1995; Lo et al., 1999) while the second lemniscal path starts from PrV multi-whisker cells and is relayed via the head of barrelo…”

“…well characterized in V1 (Bolz et al., 1989; Stratford et al., 1996; TarczyHornoch et al., 1999) but has not been characterized in the barrel column (Lefort et al., 2009; but see Zhang and Deschênes, 1997; Kumar and Ohana, 2008; Pichon et al., 2012, who show terminal endings of L6 axons in L4).”

“…learning of perceptual tasks that reflect specific characteristics of the conditioned stimulus (CS) in space and time (Disterhoft and Stuart, 1976; Kitzes et al., 1978; Diamond and Weinberger, 1986; Diamond and Weinberger, 1989; Recanzone et al., 1992, 1993; Schoups et al., 2001; Ghose et al.,…”

“…the multi-whisker response is due to integration on the ascending pathway and which one is generated by trans-columnar processing (Armstrong-James et al., 1991; Goldreich et al., 1999; Brecht and Sakmann, 2002a; Fox et al., 2003; Kwegyir-Afful et al., 2005; Katz et al., 2006; Wright and Fox, 2010).”

“At P0, this cholinergic input is confined to the cortical subplate (Hanganu and Luhmann, 2004; Dupont et al., 2006; Hanganu et al., 2009), where it causes a pronounced excitation and burst firing of subplate cells (for reviews see Luhmann et al., 2009; Kanold and Luhmann, 2010) (Fig.”

“acetylcholine (ACh), norepinephrine (NE), and other neurotransmitters which act in thalamus and cortex amongst other structures (McCormick and Bal, 1997; Buzsaki et al., 1988; Kristt, 1979; Kristt and Waldman, 1981; Houser et al., 1985).”

“…corticogenesis also controls programmed cell death (for review (Kilb et al., 2011), such as caspase-3 mediated apoptosis, by activating cell survival (e.g. neurotrophic factors) or cell death pathways (Golbs et al., 2011; Heck et al., 2008; Nimmervoll et al., 2012; Wagner-Golbs and Luhmann, 2012).”

“…(i.e. response reduction with repetitive whisker stimulation) is commonly observed in the cortex (Simons, 1978, 1985; Garabedian et al., 2003; Arabzadeh et al., 2003; Hartings et al., 2003; Webber and Stanley, 2004; Khatri et al., 2004; Stüttgen and Schwarz, 2010; Sanchez-Jimenez et al., 2009).”

“Acetylcholine release is crucial for the emergence of the barrel pattern in immature neocortex (Zhu and Waite, 1998; Zhu et al., 2002) and keeps an important role for experience-dependent functional plasticity in the mature columnar network (Ego-Stengel et al., 2001; Ramanathan et al., 2009).”

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