Compartment-specific tuning of hippocampal dendritic feature selectivity by intracellular Ca2+ release

Dendritic Ca2+ signaling is central to neural plasticity mechanisms allowing animals to adapt to the environment. Intracellular Ca2+ release (ICR) from endoplasmic reticulum has long been thought to shape these mechanisms. However, ICR has not been investigated in mammalian neurons in vivo. We combined electroporation of single CA1 pyramidal neurons, simultaneous imaging of dendritic and somatic activity during spatial navigation, optogenetic place field induction, and acute genetic augmentation of ICR cytosolic impact to reveal that ICR supports the establishment of dendritic feature selectivity and shapes integrative properties determining output-level receptive fields. This role for ICR was more prominent in apical than in basal dendrites. Thus, ICR cooperates with circuit-level architecture in vivo to promote the emergence of behaviorally-relevant plasticity in a compartment-specific manner.

Download Full-text

Feedback Decoding of Spatially Structured Population Activity in Cortical Maps

Neural Computation ◽

10.1162/neco.2008.20.1.176 ◽

2008 ◽

Vol 20 (1) ◽

pp. 176-204 ◽

Cited By ~ 6

Author(s):

Nicholas V. Swindale

Keyword(s):

Pyramidal Neurons ◽

Activity Patterns ◽

Receptive Fields ◽

Population Activity ◽

Cortical Maps ◽

Content Addressable Memory ◽

Basal Dendrites ◽

Spatially Structured Population ◽

Cortical Receptive Fields ◽

Apical Dendrites

A mechanism is proposed by which feedback pathways model spatial patterns of feedforward activity in cortical maps. The mechanism can be viewed equivalently as readout of a content-addressable memory or as decoding of a population code. The model is based on the evidence that cortical receptive fields can often be described as a separable product of functions along several dimensions, each represented in a spatially ordered map. Given this, it is shown that for an N-dimensional map, accurate modeling and decoding of xN feedforward activity patterns can be done with Nx fibers, N of which must be active at any one time. The proposed mechanism explains several known properties of the cortex and pyramidal neurons: (1) the integration of signals by dendrites with a narrow tangential distribution, that is, apical dendrites; (2) the presence of fast-conducting feedback projections with broad tangential distributions; (3) the multiplicative effects of attention on receptive field profiles; and (4) the existence of multiplicative interactions between subthreshold feedforward inputs to basal dendrites and inputs to apical dendrites.

Download Full-text

Whisker map organization in somatosensory cortex of awake, behaving mice

10.1101/587634 ◽

2019 ◽

Cited By ~ 1

Author(s):

Han Chin Wang ◽

Amy M. LeMessurier ◽

Daniel E. Feldman

Keyword(s):

Somatosensory Cortex ◽

Pyramidal Neurons ◽

Receptive Fields ◽

Pyramidal Cells ◽

Parvalbumin Interneurons ◽

Whisker Map ◽

Small Clusters ◽

Attentive Behavior ◽

Salt And Pepper

SUMMARYThe whisker map in rodent somatosensory cortex is well characterized under anesthesia, but its organization during awake sensation, when cortical coding can differ strongly, is unknown. Using a novel behavioral task, we measured whisker receptive fields and maps in awake mice with 2-photon calcium imaging in vivo. During a whisker-attentive task, layer 2/3 pyramidal neurons were sharply tuned, with cells tuned to different whiskers intermixed in each column. This salt-and-pepper organization consisted of small clusters of similarly-tuned neurons superimposed on a mean subcolumnar map. Parvalbumin interneurons had broader tuning, and were more homogeneously tuned to the columnar whisker. During a sound-attentive task, whisker tuning of pyramidal cells was less heterogeneous in each column, and firing correlations increased. Thus, behavioral demands modulate fine-scale map structure, and decorrelate the whisker map during whisker-attentive behavior.

Download Full-text

Spatiotemporally Graded NMDA Spike/Plateau Potentials in Basal Dendrites of Neocortical Pyramidal Neurons

Journal of Neurophysiology ◽

10.1152/jn.00011.2008 ◽

2008 ◽

Vol 99 (5) ◽

pp. 2584-2601 ◽

Cited By ~ 121

Author(s):

Guy Major ◽

Alon Polsky ◽

Winfried Denk ◽

Jackie Schiller ◽

David W. Tank

Keyword(s):

Decision Making ◽

Pyramidal Neurons ◽

Brain Slices ◽

Dynamic Decision Making ◽

Spatial Gradient ◽

Basal Dendrite ◽

Plateau Potentials ◽

Basal Dendrites ◽

Cortical Pyramidal Neurons

Glutamatergic inputs clustered over ∼20–40 μm can elicit local N-methyl-d-aspartate (NMDA) spike/plateau potentials in terminal dendrites of cortical pyramidal neurons, inspiring the notion that a single terminal dendrite can function as a decision-making computational subunit. A typical terminal basal dendrite is ∼100–200 μm long: could it function as multiple decision-making subunits? We test this by sequential focal stimulation of multiple sites along terminal basal dendrites of layer 5 pyramidal neurons in rat somatosensory cortical brain slices, using iontophoresis or uncaging of brief glutamate pulses. There was an approximately sevenfold spatial gradient in average spike/plateau amplitude measured at the soma, from ∼3 mV for distal inputs to ∼23 mV for proximal inputs. Spike/plateaus were NMDA receptor (NMDAR) conductance-dominated at all locations. Large Ca2+ transients accompanied spike/plateaus over a ∼10- to 40-μm zone around the input site; smaller Ca2+ transients extended approximately uniformly to the dendritic tip. Spike/plateau duration grew with increasing glutamate and depolarization; high Ca2+ zone size grew with spike/plateau duration. The minimum high Ca2+ zone half-width (just above NMDA spike threshold) increased from distal (∼10 μm) to proximal locations (∼25 μm), as did the NMDA spike glutamate threshold. Depolarization reduced glutamate thresholds. Simulations exploring multi-site interactions based on this demonstrate that if appropriately timed and localized inputs occur in vivo, a single basal dendrite could correspond to a cascade of multiple co-operating dynamic decision-making subunits able to retain information for hundreds of milliseconds, with increasing influence on neural output from distal to proximal. Dendritic NMDA spike/plateaus are thus well-suited to support graded persistent firing.

Download Full-text

Simultaneous two-photon imaging and two-photon optogenetics of cortical circuits in three dimensions

eLife ◽

10.7554/elife.32671 ◽

2018 ◽

Vol 7 ◽

Cited By ~ 61

Author(s):

Weijian Yang ◽

Luis Carrillo-Reid ◽

Yuki Bando ◽

Darcy S Peterka ◽

Rafael Yuste

Keyword(s):

Neural Activity ◽

Pyramidal Neurons ◽

Three Dimensions ◽

Cortical Circuits ◽

Two Photon ◽

Simultaneous Imaging ◽

All Optical ◽

Holographic Approach ◽

Mouse Visual Cortex

The simultaneous imaging and manipulating of neural activity could enable the functional dissection of neural circuits. Here we have combined two-photon optogenetics with simultaneous volumetric two-photon calcium imaging to measure and manipulate neural activity in mouse neocortex in vivo in three-dimensions (3D) with cellular resolution. Using a hybrid holographic approach, we simultaneously photostimulate more than 80 neurons over 150 μm in depth in layer 2/3 of the mouse visual cortex, while simultaneously imaging the activity of the surrounding neurons. We validate the usefulness of the method by photoactivating in 3D selected groups of interneurons, suppressing the response of nearby pyramidal neurons to visual stimuli in awake animals. Our all-optical approach could be used as a general platform to read and write neuronal activity.

Download Full-text

Longitudinal in vivo Imaging Reveals Balanced and Branch-Specific Remodeling of Mature Cortical Pyramidal Dendritic Arbors after Stroke

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2009.241 ◽

2009 ◽

Vol 30 (4) ◽

pp. 783-791 ◽

Cited By ~ 70

Author(s):

Craig E Brown ◽

Jamie D Boyd ◽

Timothy H Murphy

Keyword(s):

Adult Mouse ◽

Pyramidal Neurons ◽

Receptive Fields ◽

Two Photon ◽

Cortical Pyramidal Neurons ◽

Dendritic Arbors ◽

Cortical Receptive Fields ◽

Induced Changes ◽

Over Time

The manner in which fully mature peri-infarct cortical dendritic arbors remodel after stroke, and thus may possibly contribute to stroke-induced changes in cortical receptive fields, is unknown. In this study, we used longitudinal in vivo two-photon imaging to investigate the extent to which brain ischemia can trigger dendritic remodeling of pyramidal neurons in the adult mouse somatosensory cortex, and to determine the nature by which remodeling proceeds over time and space. Before the induction of stroke, dendritic arbors were relatively stable over several weeks. However, after stroke, apical dendritic arbor remodeling increased significantly (dendritic tip growth and retraction), particularly within the first 2 weeks after stroke. Despite a threefold increase in structural remodeling, the net length of arbors did not change significantly over time because dendrite extensions away from the stroke were balanced by the shortening of tips near the infarct. Therefore, fully mature cortical pyramidal neurons retain the capacity for extensive structural plasticity and remodel in a balanced and branch-specific manner.

Download Full-text

Information diversity in individual auditory cortical neurons is associated with functionally distinct coordinated neuronal ensembles

Scientific Reports ◽

10.1038/s41598-021-83565-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jermyn Z. See ◽

Natsumi Y. Homma ◽

Craig A. Atencio ◽

Vikaas S. Sohal ◽

Christoph E. Schreiner

Keyword(s):

Cortical Neurons ◽

Single Neuron ◽

Receptive Fields ◽

Acoustic Feature ◽

Neuronal Ensembles ◽

Neuron Spike ◽

Information Diversity ◽

Feature Selectivity ◽

Stimulus Features ◽

Time Specific

AbstractNeuronal activity in auditory cortex is often highly synchronous between neighboring neurons. Such coordinated activity is thought to be crucial for information processing. We determined the functional properties of coordinated neuronal ensembles (cNEs) within primary auditory cortical (AI) columns relative to the contributing neurons. Nearly half of AI cNEs showed robust spectro-temporal receptive fields whereas the remaining cNEs showed little or no acoustic feature selectivity. cNEs can therefore capture either specific, time-locked information of spectro-temporal stimulus features or reflect stimulus-unspecific, less-time specific processing aspects. By contrast, we show that individual neurons can represent both of those aspects through membership in multiple cNEs with either high or absent feature selectivity. These associations produce functionally heterogeneous spikes identifiable by instantaneous association with different cNEs. This demonstrates that single neuron spike trains can sequentially convey multiple aspects that contribute to cortical processing, including stimulus-specific and unspecific information.

Download Full-text

A Collagen-Based Scaffold for Promoting Neural Plasticity in a Rat Model of Spinal Cord Injury

Polymers ◽

10.3390/polym12102245 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2245

Author(s):

Jue-Zong Yeh ◽

Ding-Han Wang ◽

Juin-Hong Cherng ◽

Yi-Wen Wang ◽

Gang-Yi Fan ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Rat Model ◽

Neural Plasticity ◽

Collagen Scaffold ◽

Glial Scar ◽

Beneficial Effects ◽

Cord Injury

In spinal cord injury (SCI) therapy, glial scarring formed by activated astrocytes is a primary problem that needs to be solved to enhance axonal regeneration. In this study, we developed and used a collagen scaffold for glial scar replacement to create an appropriate environment in an SCI rat model and determined whether neural plasticity can be manipulated using this approach. We used four experimental groups, as follows: SCI-collagen scaffold, SCI control, normal spinal cord-collagen scaffold, and normal control. The collagen scaffold showed excellent in vitro and in vivo biocompatibility. Immunofluorescence staining revealed increased expression of neurofilament and fibronectin and reduced expression of glial fibrillary acidic protein and anti-chondroitin sulfate in the collagen scaffold-treated SCI rats at 1 and 4 weeks post-implantation compared with that in untreated SCI control. This indicates that the collagen scaffold implantation promoted neuronal survival and axonal growth within the injured site and prevented glial scar formation by controlling astrocyte production for their normal functioning. Our study highlights the feasibility of using the collagen scaffold in SCI repair. The collagen scaffold was found to exert beneficial effects on neuronal activity and may help in manipulating synaptic plasticity, implying its great potential for clinical application in SCI.

Download Full-text

Paradoxical effect of salbutamol in a model of acute organophosphates intoxication in guinea pigs: role of substance P release

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00253.2005 ◽

2007 ◽

Vol 292 (4) ◽

pp. L915-L923 ◽

Cited By ~ 10

Author(s):

Jaime Chávez ◽

Patricia Segura ◽

Mario H. Vargas ◽

José Luis Arreola ◽

Edgar Flores-Soto ◽

...

Keyword(s):

Substance P ◽

Guinea Pigs ◽

Smooth Muscle Contraction ◽

In Vivo Experiments ◽

Intracellular Ca ◽

Neurokinin 1 ◽

Substance P Release

Organophosphates induce bronchoobstruction in guinea pigs, and salbutamol only transiently reverses this effect, suggesting that it triggers additional obstructive mechanisms. To further explore this phenomenon, in vivo (barometric plethysmography) and in vitro (organ baths, including ACh and substance P concentration measurement by HPLC and immunoassay, respectively; intracellular Ca2+ measurement in single myocytes) experiments were performed. In in vivo experiments, parathion caused a progressive bronchoobstruction until a plateau was reached. Administration of salbutamol during this plateau decreased bronchoobstruction up to 22% in the first 5 min, but thereafter airway obstruction rose again as to reach the same intensity as before salbutamol. Aminophylline caused a sustained decrement (71%) of the parathion-induced bronchoobstruction. In in vitro studies, paraoxon produced a sustained contraction of tracheal rings, which was fully blocked by atropine but not by TTX, ω-conotoxin (CTX), or epithelium removal. During the paraoxon-induced contraction, salbutamol caused a temporary relaxation of ∼50%, followed by a partial recontraction. This paradoxical recontraction was avoided by the M2- or neurokinin-1 (NK1)-receptor antagonists (methoctramine or AF-DX 116, and L-732138, respectively), accompanied by a long-lasting relaxation. Forskolin caused full relaxation of the paraoxon response. Substance P and, to a lesser extent, ACh released from tracheal rings during 60-min incubation with paraoxon or physostigmine, respectively, were significantly increased when salbutamol was administered in the second half of this period. In myocytes, paraoxon did not produce any change in the intracellular Ca2+ basal levels. Our results suggested that: 1) organophosphates caused smooth muscle contraction by accumulation of ACh released through a TTX- and CTX-resistant mechanism; 2) during such contraction, salbutamol relaxation is functionally antagonized by the stimulation of M2 receptors; and 3) after this transient salbutamol-induced relaxation, a paradoxical contraction ensues due to the subsequent release of substance P.

Download Full-text