51
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Morgenstern NA, Bourg J, Petreanu L. Multilaminar networks of cortical neurons integrate common inputs from sensory thalamus. Nat Neurosci 2016; 19:1034-40. [PMID: 27376765 DOI: 10.1038/nn.4339] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/26/2016] [Indexed: 12/12/2022]
Abstract
Neurons in the thalamorecipient layers of sensory cortices integrate thalamic and recurrent cortical input. Cortical neurons form fine-scale, functionally cotuned networks, but whether interconnected cortical neurons within a column process common thalamocortical inputs is unknown. We tested how local and thalamocortical connectivity relate to each other by analyzing cofluctuations of evoked responses in cortical neurons after photostimulation of thalamocortical axons. We found that connected pairs of pyramidal neurons in layer (L) 4 of mouse visual cortex share more inputs from the dorsal lateral geniculate nucleus than nonconnected pairs. Vertically aligned connected pairs of L4 and L2/3 neurons were also preferentially contacted by the same thalamocortical axons. Our results provide a circuit mechanism for the observed amplification of sensory responses by L4 circuits. They also show that sensory information is concurrently processed in L4 and L2/3 by columnar networks of interconnected neurons contacted by the same thalamocortical axons.
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Affiliation(s)
- Nicolás A Morgenstern
- Champalimaud Neuroscience Programme, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - Jacques Bourg
- Champalimaud Neuroscience Programme, Champalimaud Center for the Unknown, Lisbon, Portugal
| | - Leopoldo Petreanu
- Champalimaud Neuroscience Programme, Champalimaud Center for the Unknown, Lisbon, Portugal
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52
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Impaired immunological synapse in sperm associated antigen 6 (SPAG6) deficient mice. Sci Rep 2016; 6:25840. [PMID: 27169488 PMCID: PMC4864328 DOI: 10.1038/srep25840] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 04/22/2016] [Indexed: 11/18/2022] Open
Abstract
Sperm associated antigen 6 (SPAG6), a component of the central apparatus of the “9 + 2” axoneme, plays a central role in ciliary and flagellar motility; but, its contribution to adaptive immunity and immune system development is completely unknown. While immune cells lack a cilium, the immunological synapse is a surrogate cilium as it utilizes the same machinery as ciliogenesis including the nucleation of microtubules at the centrosome. This prompted our hypothesis that SPAG6 critically regulates the formation and function of immunological synapses. Using bone marrow reconstitution studies of adult WT mice, we demonstrate that SPAG6 is expressed in primary and secondary lymphoid tissues, is associated with the centrosome in lymphocytes, and its deficiency results in synapse disruption due to loss of centrosome polarization and actin clearance at the synaptic cleft. Improper synapse formation in Spag6KO mice was associated with defective CTL functions and impaired humoral immunity as indicated by reduced germinal centers reactions, follicular CD4 T cells, and production of class-switched antibody, together with expansion of B1 B cells. This novel report demonstrates the requirement of SPAG6 for optimal synapse formation and function, its direct role in immune cell function, and provides a novel mechanism for infertility disorders related to SPAG6.
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53
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Haider B, Schulz DPA, Häusser M, Carandini M. Millisecond Coupling of Local Field Potentials to Synaptic Currents in the Awake Visual Cortex. Neuron 2016; 90:35-42. [PMID: 27021173 PMCID: PMC4826437 DOI: 10.1016/j.neuron.2016.02.034] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 10/23/2015] [Accepted: 02/16/2016] [Indexed: 12/31/2022]
Abstract
The cortical local field potential (LFP) is a common measure of population activity, but its relationship to synaptic activity in individual neurons is not fully established. This relationship has been typically studied during anesthesia and is obscured by shared slow fluctuations. Here, we used patch-clamp recordings in visual cortex of anesthetized and awake mice to measure intracellular activity; we then applied a simple method to reveal its coupling to the simultaneously recorded LFP. LFP predicted membrane potential as accurately as synaptic currents, indicating a major role for synaptic currents in the relationship between cortical LFP and intracellular activity. During anesthesia, cortical LFP predicted excitation far better than inhibition; during wakefulness, it predicted them equally well, and visual stimulation further enhanced predictions of inhibition. These findings reveal a central role for synaptic currents, and especially inhibition, in the relationship between the subthreshold activity of individual neurons and the cortical LFP during wakefulness.
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Affiliation(s)
- Bilal Haider
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK.
| | - David P A Schulz
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Michael Häusser
- Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Matteo Carandini
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
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54
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Biane JS, Takashima Y, Scanziani M, Conner JM, Tuszynski MH. Thalamocortical Projections onto Behaviorally Relevant Neurons Exhibit Plasticity during Adult Motor Learning. Neuron 2016; 89:1173-1179. [PMID: 26948893 DOI: 10.1016/j.neuron.2016.02.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 12/08/2015] [Accepted: 01/21/2016] [Indexed: 01/28/2023]
Abstract
Layer 5 neurons of the neocortex receive direct and relatively strong input from the thalamus. However, the intralaminar distribution of these inputs and their capacity for plasticity in adult animals are largely unknown. In slices of the primary motor cortex (M1), we simultaneously recorded from pairs of corticospinal neurons associated with control of distinct motor outputs: distal forelimb versus proximal forelimb. Activation of ChR2-expressing thalamocortical afferents in M1 before motor learning produced equivalent responses in monosynaptic excitation of neurons controlling the distal and proximal forelimb, suggesting balanced thalamic input at baseline. Following skilled grasp training, however, thalamocortical input shifted to bias activation of corticospinal neurons associated with control of the distal forelimb. This increase was associated with a cell-specific increase in mEPSC amplitude but not presynaptic release probability. These findings demonstrate distinct and highly segregated plasticity of thalamocortical projections during adult learning.
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Affiliation(s)
- Jeremy S Biane
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093
| | - Yoshio Takashima
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093
| | - Massimo Scanziani
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093; Department of Neurobiology, University of California, San Diego, La Jolla, CA 92093; Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA 92093
| | - James M Conner
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093
| | - Mark H Tuszynski
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093; Veterans Affairs Medical Center, San Diego, CA 92161.
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55
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Bickford ME. Thalamic Circuit Diversity: Modulation of the Driver/Modulator Framework. Front Neural Circuits 2016; 9:86. [PMID: 26793068 PMCID: PMC4709853 DOI: 10.3389/fncir.2015.00086] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 12/15/2015] [Indexed: 12/17/2022] Open
Abstract
The idea that dorsal thalamic inputs can be divided into “drivers”, which provide the primary excitatory drive for the relay of information to cortex, and “modulators”, which alter the gain of signal transmission, has provided a valuable organizing principle for the study of thalamic function. This view further promoted the identification of “first order” and “higher order” thalamic nuclei, based on the origin of their driving inputs. Since the introduction of this influential terminology, a number of studies have revealed the existence of a wide variety of thalamic organizational schemes. For example, some thalamic nuclei are not innervated by typical driver inputs, but instead receive input from terminals which exhibit features distinct from those of either classic drivers or modulators. In addition, many thalamic nuclei contain unique combinations of convergent first order, higher order, and/or other “driver-like” inputs that do not conform with the driver/modulator framework. The assortment of synaptic arrangements identified in the thalamus are reviewed and discussed from the perspective that this organizational diversity can dramatically increase the computational capabilities of the thalamus, reflecting its essential roles in sensory, motor, and sensory-motor circuits.
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Affiliation(s)
- Martha E Bickford
- Department of Anatomical Sciences and Neurobiology, University of Louisville Louisville, KY, USA
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56
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An analysis of nonlinear dynamics underlying neural activity related to auditory induction in the rat auditory cortex. Neuroscience 2016; 318:58-83. [PMID: 26772432 DOI: 10.1016/j.neuroscience.2015.12.060] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 12/31/2015] [Accepted: 12/31/2015] [Indexed: 11/20/2022]
Abstract
A sound interrupted by silence is perceived as discontinuous. However, when high-intensity noise is inserted during the silence, the missing sound may be perceptually restored and be heard as uninterrupted. This illusory phenomenon is called auditory induction. Recent electrophysiological studies have revealed that auditory induction is associated with the primary auditory cortex (A1). Although experimental evidence has been accumulating, the neural mechanisms underlying auditory induction in A1 neurons are poorly understood. To elucidate this, we used both experimental and computational approaches. First, using an optical imaging method, we characterized population responses across auditory cortical fields to sound and identified five subfields in rats. Next, we examined neural population activity related to auditory induction with high temporal and spatial resolution in the rat auditory cortex (AC), including the A1 and several other AC subfields. Our imaging results showed that tone-burst stimuli interrupted by a silent gap elicited early phasic responses to the first tone and similar or smaller responses to the second tone following the gap. In contrast, tone stimuli interrupted by broadband noise (BN), considered to cause auditory induction, considerably suppressed or eliminated responses to the tone following the noise. Additionally, tone-burst stimuli that were interrupted by notched noise centered at the tone frequency, which is considered to decrease the strength of auditory induction, partially restored the second responses from the suppression caused by BN. To phenomenologically mimic the neural population activity in the A1 and thus investigate the mechanisms underlying auditory induction, we constructed a computational model from the periphery through the AC, including a nonlinear dynamical system. The computational model successively reproduced some of the above-mentioned experimental results. Therefore, our results suggest that a nonlinear, self-exciting system is a key element for qualitatively reproducing A1 population activity and to understand the underlying mechanisms.
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57
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Lewis DA, Glausier JR. Alterations in Prefrontal Cortical Circuitry and Cognitive Dysfunction in Schizophrenia. NEBRASKA SYMPOSIUM ON MOTIVATION. NEBRASKA SYMPOSIUM ON MOTIVATION 2016; 63:31-75. [PMID: 27627824 DOI: 10.1007/978-3-319-30596-7_3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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58
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Wagener RJ, Witte M, Guy J, Mingo-Moreno N, Kügler S, Staiger JF. Thalamocortical Connections Drive Intracortical Activation of Functional Columns in the Mislaminated Reeler Somatosensory Cortex. Cereb Cortex 2015; 26:820-37. [PMID: 26564256 PMCID: PMC4712806 DOI: 10.1093/cercor/bhv257] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Neuronal wiring is key to proper neural information processing. Tactile information from the rodent's whiskers reaches the cortex via distinct anatomical pathways. The lemniscal pathway relays whisking and touch information from the ventral posteromedial thalamic nucleus to layer IV of the primary somatosensory “barrel” cortex. The disorganized neocortex of the reeler mouse is a model system that should severely compromise the ingrowth of thalamocortical axons (TCAs) into the cortex. Moreover, it could disrupt intracortical wiring. We found that neuronal intermingling within the reeler barrel cortex substantially exceeded previous descriptions, leading to the loss of layers. However, viral tracing revealed that TCAs still specifically targeted transgenically labeled spiny layer IV neurons. Slice electrophysiology and optogenetics proved that these connections represent functional synapses. In addition, we assessed intracortical activation via immediate-early-gene expression resulting from a behavioral exploration task. The cellular composition of activated neuronal ensembles suggests extensive similarities in intracolumnar information processing in the wild-type and reeler brains. We conclude that extensive ectopic positioning of neuronal partners can be compensated for by cell-autonomous mechanisms that allow for the establishment of proper connectivity. Thus, genetic neuronal fate seems to be of greater importance for correct cortical wiring than radial neuronal position.
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Affiliation(s)
- Robin J Wagener
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Mirko Witte
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Julien Guy
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Nieves Mingo-Moreno
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Sebastian Kügler
- Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany Department of Neurology, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany
| | - Jochen F Staiger
- Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität Göttingen, 37075 Göttingen, Germany Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
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59
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Distinct recurrent versus afferent dynamics in cortical visual processing. Nat Neurosci 2015; 18:1789-97. [PMID: 26502263 DOI: 10.1038/nn.4153] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/30/2015] [Indexed: 01/21/2023]
Abstract
How intracortical recurrent circuits in mammalian sensory cortex influence dynamics of sensory representation is not understood. Previous methods could not distinguish the relative contributions of recurrent circuits and thalamic afferents to cortical dynamics. We accomplish this by optogenetically manipulating thalamus and cortex. Over the initial 40 ms of visual stimulation, excitation from recurrent circuits in visual cortex progressively increased to exceed direct thalamocortical excitation. Even when recurrent excitation exceeded thalamic excitation, upon silencing thalamus, sensory-evoked activity in cortex decayed rapidly, with a time constant of 10 ms, which is similar to a neuron's integration time window. In awake mice, this cortical decay function predicted the time-locking of cortical activity to thalamic input at frequencies <15 Hz and attenuation of the cortical response to higher frequencies. Under anesthesia, depression at thalamocortical synapses disrupted the fidelity of sensory transmission. Thus, we determine dynamics intrinsic to cortical recurrent circuits that transform afferent input in time.
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60
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Malkin S, Kim K, Tikhonov D, Magazanik L, Zaitsev A. Statistical models suggest presence of two distinct subpopulations of miniature EPSCs in fast-spiking interneurons of rat prefrontal cortex. Neuroscience 2015; 301:508-19. [DOI: 10.1016/j.neuroscience.2015.06.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/18/2015] [Accepted: 06/18/2015] [Indexed: 01/30/2023]
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61
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Trachtenberg JT. Competition, inhibition, and critical periods of cortical plasticity. Curr Opin Neurobiol 2015; 35:44-8. [PMID: 26126153 DOI: 10.1016/j.conb.2015.06.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 06/15/2015] [Indexed: 11/17/2022]
Abstract
Maturation of cortical inhibition just after eye opening is a necessary precedent for the emergence of competitive, experience-dependent ocular dominance plasticity in the visual cortex. What inhibition is doing in this context, though, is not clear. Here I outline new hypotheses on the roles of somatic and dendritic inhibition in the opening and closure of critical periods, and their roles in the competitive processes therein.
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62
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Gonzalez-Burgos G, Cho RY, Lewis DA. Alterations in cortical network oscillations and parvalbumin neurons in schizophrenia. Biol Psychiatry 2015; 77:1031-40. [PMID: 25863358 PMCID: PMC4444373 DOI: 10.1016/j.biopsych.2015.03.010] [Citation(s) in RCA: 352] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 02/09/2015] [Accepted: 03/07/2015] [Indexed: 11/17/2022]
Abstract
Cognitive deficits are a core clinical feature of schizophrenia but respond poorly to available medications. Thus, understanding the neural basis of these deficits is crucial for the development of new therapeutic interventions. The types of cognitive processes affected in schizophrenia are thought to depend on the precisely timed transmission of information in cortical regions via synchronous oscillations at gamma band frequency. Here, we review 1) data from clinical studies suggesting that induction of frontal cortex gamma oscillations during tasks that engage cognitive or complex perceptual functions is attenuated in schizophrenia; 2) findings from basic neuroscience studies highlighting the features of parvalbumin-positive interneurons that are critical for gamma oscillation production; and 3) results from recent postmortem human brain studies providing additional molecular bases for parvalbumin-positive interneuron alterations in prefrontal cortical circuitry in schizophrenia.
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Affiliation(s)
| | - Raymond Y Cho
- Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at Houston, Houston, Texas
| | - David A Lewis
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburg, Pennsylvania.
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63
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Shigematsu N, Ueta Y, Mohamed AA, Hatada S, Fukuda T, Kubota Y, Kawaguchi Y. Selective Thalamic Innervation of Rat Frontal Cortical Neurons. Cereb Cortex 2015; 26:2689-2704. [PMID: 26045568 DOI: 10.1093/cercor/bhv124] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Most glutamatergic inputs in the neocortex originate from the thalamus or neocortical pyramidal cells. To test whether thalamocortical afferents selectively innervate specific cortical cell subtypes and surface domains, we investigated the distribution patterns of thalamocortical and corticocortical excitatory synaptic inputs in identified postsynaptic cortical cell subtypes using intracellular and immunohistochemical staining combined with confocal laser scanning and electron microscopic observations in 2 thalamorecipient sublayers, lower layer 2/3 (L2/3b) and lower layer 5 (L5b) of rat frontal cortex. The dendrites of GABAergic parvalbumin (PV) cells preferentially received corticocortical inputs in both sublayers. The somata of L2/3b PV cells received thalamic inputs in similar proportions to the basal dendritic spines of L2/3b pyramidal cells, whereas L5b PV somata were mostly innervated by cortical inputs. The basal dendrites of L2/3b pyramidal and L5b corticopontine pyramidal cells received cortical and thalamic glutamatergic inputs in proportion to their local abundance, whereas crossed-corticostriatal pyramidal cells in L5b exhibited a preference for thalamic inputs, particularly in their distal dendrites. Our data demonstrate an exquisite selectivity among thalamocortical afferents in which synaptic connectivity is dependent on the postsynaptic neuron subtype, cortical sublayer, and cell surface domain.
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Affiliation(s)
- Naoki Shigematsu
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8787, Japan.,Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan.,JST, CREST, Tokyo 102-0076, Japan
| | - Yoshifumi Ueta
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8787, Japan.,JST, CREST, Tokyo 102-0076, Japan
| | - Alsayed A Mohamed
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8787, Japan.,Department of Anatomy and Embryology, Faculty of Veterinary Medicine, South Valley University, Qena 83523, Arab Republic of Egypt
| | - Sayuri Hatada
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8787, Japan
| | - Takaichi Fukuda
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan
| | - Yoshiyuki Kubota
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8787, Japan.,JST, CREST, Tokyo 102-0076, Japan.,Department of Physiological Sciences, SOKENDAI (Graduate University for Advanced Studies), Okazaki 444-8787, Japan
| | - Yasuo Kawaguchi
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8787, Japan.,JST, CREST, Tokyo 102-0076, Japan.,Department of Physiological Sciences, SOKENDAI (Graduate University for Advanced Studies), Okazaki 444-8787, Japan
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64
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Ji XY, Zingg B, Mesik L, Xiao Z, Zhang LI, Tao HW. Thalamocortical Innervation Pattern in Mouse Auditory and Visual Cortex: Laminar and Cell-Type Specificity. Cereb Cortex 2015; 26:2612-25. [PMID: 25979090 DOI: 10.1093/cercor/bhv099] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Despite many previous studies, the functional innervation pattern of thalamic axons and their target specificity remains to be investigated thoroughly. Here, in primary auditory cortical slices, we examined thalamic innervation patterns for excitatory and different types of inhibitory neurons across laminae, by optogenetically stimulating axons from the medial geniculate body. We found that excitatory cells and parvalbumin (PV)-expressing inhibitory neurons across layer 2/3 (L2/3) to L6 are directly innervated by thalamic projections, with the strongest innervation occurring in L4. The innervation of PV neurons is stronger than that of excitatory neurons in the same layer, with a relatively constant ratio between their innervation strengths across layers. For somatostatin and vasoactive intestinal peptide inhibitory neurons, essentially only L4 neurons were innervated by thalamic axons and the innervation was much weaker compared with excitatory and PV cells. In addition, more than half of inhibitory neurons in L1 were innervated, relatively strongly, by thalamic axons. Similar innervation patterns were also observed in the primary visual cortex. Thus, thalamic information can be processed independently and differentially by different cortical layers, in addition to the generally thought hierarchical processing starting from L4. This parallel processing is likely shaped by feedforward inhibition from PV neurons in each individual lamina, and may extend the computation power of sensory cortices.
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Affiliation(s)
- Xu-Ying Ji
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China Zilkha Neurogenetic Institute
| | - Brian Zingg
- Zilkha Neurogenetic Institute Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Lukas Mesik
- Zilkha Neurogenetic Institute Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
| | - Zhongju Xiao
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Li I Zhang
- Zilkha Neurogenetic Institute Department of Biophysics and Physiology
| | - Huizhong W Tao
- Zilkha Neurogenetic Institute Department of Cell and Neurobiology
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