Representations of odor in the piriform cortex

Slides:



Advertisements
Similar presentations
Laser-Scanning Microscopy as a Tool to Study the Spatio-Temporal Organization of InsP 3 -Mediated Ca 2+ signaling.
Advertisements

Dan D. Stettler and Richard Axel REPRESENTATIONS OF ODOR IN THE PIRIFORM CORTEX Neuron 63, p (2009)
Functional cellular imaging by light microscopy MICROSCOPIES.
Date of download: 6/21/2016 Copyright © 2016 SPIE. All rights reserved. Combined two-photon and electrophysiological recording of human neocortical neuronal.
Date of download: 6/25/2016 Copyright © 2016 SPIE. All rights reserved. Expression of channelrhodopsin-2 (ChR2) in layer 5 pyramidal neurons in the barrel.
Volume 22, Issue 16, Pages (August 2012)
Volume 9, Issue 5, Pages (December 2014)
Development of Direction Selectivity in Mouse Cortical Neurons
Precise Circuitry Links Bilaterally Symmetric Olfactory Maps
Guangying K. Wu, Pingyang Li, Huizhong W. Tao, Li I. Zhang  Neuron 
Representations of Odor in the Piriform Cortex
A Major Role for Intracortical Circuits in the Strength and Tuning of Odor-Evoked Excitation in Olfactory Cortex  Cindy Poo, Jeffry S. Isaacson  Neuron 
Volume 71, Issue 5, Pages (September 2011)
Spatial representation and the architecture of the entorhinal cortex
Volume 26, Issue 13, Pages (July 2016)
Dense Inhibitory Connectivity in Neocortex
Axons and Synaptic Boutons Are Highly Dynamic in Adult Visual Cortex
James H. Marshel, Alfred P. Kaye, Ian Nauhaus, Edward M. Callaway 
Network-Level Control of Frequency Tuning in Auditory Cortex
Carlos D. Brody, J.J. Hopfield  Neuron 
Volume 24, Issue 13, Pages e5 (September 2018)
Volume 87, Issue 6, Pages (September 2015)
Odor Processing by Adult-Born Neurons
Volume 80, Issue 3, Pages (October 2013)
Jenelle L. Wallace, Martin Wienisch, Venkatesh N. Murthy  Neuron 
Volume 7, Issue 5, Pages (June 2014)
Volume 57, Issue 2, Pages (January 2008)
How Inhibition Shapes Cortical Activity
Jonathan J. Nassi, David C. Lyon, Edward M. Callaway  Neuron 
Transient and Persistent Dendritic Spines in the Neocortex In Vivo
Benjamin Scholl, Daniel E. Wilson, David Fitzpatrick  Neuron 
Volume 74, Issue 2, Pages (April 2012)
Development of Direction Selectivity in Mouse Cortical Neurons
Volume 57, Issue 4, Pages (February 2008)
Volume 26, Issue 13, Pages (July 2016)
Patrick Kaifosh, Attila Losonczy  Neuron 
Tiago Branco, Michael Häusser  Neuron 
Dendritic Spines and Distributed Circuits
Receptive-Field Modification in Rat Visual Cortex Induced by Paired Visual Stimulation and Single-Cell Spiking  C. Daniel Meliza, Yang Dan  Neuron  Volume.
Ryan G. Natan, Winnie Rao, Maria N. Geffen  Cell Reports 
Volume 44, Issue 1, Pages (September 2004)
Sleep-Stage-Specific Regulation of Cortical Excitation and Inhibition
Volume 77, Issue 6, Pages (March 2013)
There and Back Again: The Corticobulbar Loop
Monica W. Chu, Wankun L. Li, Takaki Komiyama  Neuron 
Ingrid Bureau, Gordon M.G Shepherd, Karel Svoboda  Neuron 
Distinct Translaminar Glutamatergic Circuits to GABAergic Interneurons in the Neonatal Auditory Cortex  Rongkang Deng, Joseph P.Y. Kao, Patrick O. Kanold 
Volume 70, Issue 2, Pages (April 2011)
Benjamin Scholl, Daniel E. Wilson, David Fitzpatrick  Neuron 
Hiroyuki K. Kato, Shea N. Gillet, Jeffry S. Isaacson  Neuron 
Broadcasting of Cortical Activity to the Olfactory Bulb
Dendritic Integration in Mammalian Neurons, a Century after Cajal
From Functional Architecture to Functional Connectomics
Volume 87, Issue 6, Pages (September 2015)
Cortical Processing of Odor Objects
Structured Connectivity in Cerebellar Inhibitory Networks
James H. Marshel, Takuma Mori, Kristina J. Nielsen, Edward M. Callaway 
Cortical Microcircuits
Volume 57, Issue 2, Pages (January 2008)
Volume 77, Issue 6, Pages (March 2013)
Tomokazu Sato, Mikhail G. Shapiro, Doris Y. Tsao  Neuron 
Xiaowei Chen, Nathalie L. Rochefort, Bert Sakmann, Arthur Konnerth 
Claudia Lodovichi, Leonardo Belluscio, Lawrence C Katz  Neuron 
Volume 61, Issue 2, Pages (January 2009)
Volume 27, Issue 2, Pages (August 2000)
The superior colliculus
Combinatorial and Chemotopic Odorant Coding in the Zebrafish Olfactory Bulb Visualized by Optical Imaging  Rainer W Friedrich, Sigrun I Korsching  Neuron 
Volume 44, Issue 1, Pages (September 2004)
Cristopher M. Niell, Stephen J Smith  Neuron 
Patrick Kaifosh, Attila Losonczy  Neuron 
Presentation transcript:

Representations of odor in the piriform cortex Dan D. Stettler and Richard Axel Neuron 63, p. 854-864 (2009)

The olfactory bulb is quite organized

The piriform cortex 3-layered structure pyramidal Figure 1. Schematic diagram of the location and anatomy of the piriform cortex. A, Ventrolateral aspect of the rat brain, showing the olfactory bulb (OB), lateral olfactory tract (LOT), and the locations of the anterior and posterior piriform cortex (aPC and pPC, respectively), which are approximately demarcated by the dashed line. rf, rhinal fissure. A coronal slice of the aPC, taken between the arrows, shows the laminar structure illustrated schematically in panel B. B, The three main layers of the PC. At left is a schematic representation of the density of neuronal somata in each layer, showing the high density of mainly principal cells in Layer II, and a lower density of neurons in Layers I and III. Schematic diagrams of the dendritic trees of the two main types of Layer II principal cells (SP, superficial pyramidal; SL, semilunar) and one type of Layer III principal cell (DP, deep pyramidal) are shown in grey. Schematic diagrams of the dendritic trees of four types of GABAergic interneurons are shown in black (B, bitufted; G, neurogliaform; H, horizontal; M, multipolar). The scale bar is approximate. Adapted from Neville and Haberly (2004).1 The piriform cortex is a three-layered structure on the ventral lateral surface of the cerebral hemisphere (Figure 1A). The major projection neurons of the piriform cortex, the pyramidal cells, locate their cell bodies in layers 2 and 3 and extend apical dendrites to layer 1 where they synapse with mitral cell afferents from the olfactory bulb (Figure 1B). 3-layered structure On the ventral-lateral surface of the cerebral hemisphere Synapse with mitral cell afferents in layer 1 http://aups.org.au/Proceedings/38/9-14/

For the calcium imaging the calcium sensitive fluorescent dye Oregon Green 488 BAPTA-1 AM was used. The dye was injected into broad regions of layer 1, causing the labeling of > 90% of the pyramidal cell bodies in layers 2 and 3 across wide regions in the piriform cortex. Imaged at multiple sites in over 100 mice.

Odorant-Evoked Responses in Mouse Piriform Using In Vivo Two-Photon Calcium Imaging

Odorants Evoke Responses in Unique but Overlapping Ensembles of Piriform Neurons

Odorants Evoke Responses in Unique but Overlapping Ensembles of Piriform Neurons

Distributed Odorant Representations Extend across Wide Regions of Piriform Cortex

The Response of Piriform Cells to a Mix of Odorants Exhibits Strong Suppression and Weak Synergy

A model of piriform responses based upon random connectivity between the bulb and piriform can generate the observed odorant representations

Conclusions Unlike visual, auditory or somatosensory cortical sensory areas: The piriform cortex discards the spatial segregation and chemotopy apparent in earlier stages of the olfactory system. The piriform shows a highly distributed organization in which different odorants activate unique but dispersed ensembles of cortical neurons. Neurons in the piriform cortex don’t have an apparent continuos receptive fields (chemotopy, ….behavioral What else was checked?) → It should be remembered, though, that a relevant odors space still needs to be defined, while in other senses this step is more straight-forward. Caveat – results are dependent on thresholds of imaging

Glutamate blockade diminishes odorant-evoked responses

Monte Carlo simulations of responsive cell distributions.

Auto- and cross- correlation analysis reveals no consistent fine-scale patterning in odorant responses.

Motivation Measuring the input to neurons. In electrical measurements one finds: directional selectivity of the firing rate but no directional selectivity under hyperpolarization – indicating a low tuning level of the inputs. POSSIBILITIES OF INPUT TUNING AND ORGANIZATION: Untuned Tuned and clustered Tuned and dispersed Investigating the activity under hyperpolarization

Heterogeneous distribution of pure-tone-activated spines along dendrites. Xiaowei Chen, Ulrich Leischner, Nathalie L. Rochefort, Israel Nelken & Arthur Konnerth Functional mapping of single spines in cortical neurons in vivo Nature 475, 501–505

http://www. nobelprize http://www.nobelprize.org/nobel_prizes/medicine/laureates/2004/illpres/2_olfactory.html

2-photon microscope

Practical theory of 2-photon microscopy Near simultaneous absorption of the energy of two infrared photons results in excitation of a fluorochrome that would normally be excited by a single photon of twice the energy. The probability of excitation depends on the square of the infrared intensity and decreases rapidly with distance from the focal volume.

Advantages of 2-photon microscopy Increased penetration of infrared light allows deeper imaging. No out-of-focus fluorescence. Photo-damage and bleaching are confined to diffraction- limited spot. Multiple fluorochrome excitation allows simultaneous, diffraction-limited, co-localization. Imaging of UV-excited compounds with conventional optics.