K a r i m B e n c h e n a n e Importance of rhythms for cell - - PowerPoint PPT Presentation
K a r i m B e n c h e n a n e Importance of rhythms for cell - - PowerPoint PPT Presentation
K a r i m B e n c h e n a n e Importance of rhythms for cell assemblies synchronization Master BIP - Dec 1th 2015 << Importance of rhythms in cell assemblies synchronization 1) Cell assemblies 2) Rhythms 3) Rhythms and cell
1) Cell assemblies 2) Rhythms 3) Rhythms and cell assemblies
Importance of rhythms in cell assemblies synchronization
Extracellular electrophysiological recordings
PPSE PPSI PPSE PPSE PPSE PPSI PPSI
Local Field Potential = Sum of all PPSE and PPSI
Action potential (spike) Action potential (spike) Action potential (spike) Action potential (spike)
LFP = Input Spike = Output
Excitatory** input*
?*
Excitatory** input*
LFP$electrode$ superficial+ LFP$electrode$ deep+ Excitatory** input*
?* ?*
LFP$electrode$ superficial+ LFP$electrode$ deep+ Excitatory** input*
LFP$electrode$ superficial+ LFP$electrode$ deep+ Inhibitory* input*
?* ?* ?*
LFP$electrode$ superficial+ LFP$electrode$ deep+ Inhibitory* input*
LFP$electrode$ superficial+ LFP$electrode$ deep+ Excitatory** input*
LFP$electrode$ superficial+ LFP$electrode$ deep+ Inhibitory* input*
?* ?* ?*
LFP$electrode$ superficial+ LFP$electrode$ deep+ Inhibitory* input*
LFP$electrode$ superficial+ LFP$electrode$ deep+ Excitatory** input*
Reference' Cortex'pariétal'
Reference' Cortex'pariétal'
Reference' Cortex'pariétal'
Reference' Cortex'pariétal'
Extracellular electrophysiological recordings
Extracellular electrophysiological recordings
Extracellular electrophysiological recordings
Note that in a particular condition 90% of the neurons are silent Extracellular electrophysiological recordings
Extracellular electrophysiological recordings
Extracellular recordings in human (epileptic patients)
Quian Quiroga et al., Nature 2005
Neural bases of semantic memory
Neural bases of semantic memory
Quian Quiroga et al., Nature 2005
Neural bases of semantic memory
Quian Quiroga et al., Nature 2005
Response in IT : ~130 ms (primate) Response in MTL: ~250-300 ms Recognition in human : ~150ms
The cell responding to pictures of Darth Vador might not be involved in recognizing him Crucial for the storage of new long-term memories and related to the fact that the patient viewed his pictures in the clinic.
1/ Presentation of several movies with different actors 2/ Recollection task: which movies have you seen? Gelbard-Sagiv, et al., Science, 2008
Neural bases of semantic memory
Place cell
Jung, Wiener et McNaughton,1994
The position of the animal can be predicted by the neuronal activity in the hippocampus
Internal representation of space in the hippocampus
The position of the animal can be predicted by the neuronal activity in the hippocampus
Place cell
Internal representation of space in the hippocampus
- Place cells properties:
– Discharge a pyramidal neurons related to the position of the animal – Place Field is formed after few minutes and is stable for months – Rotation of external cues induce the rotation of place fields – A particular place cells have different place fields in different contexts
Internal representation of space in the hippocampus
- Place cells properties:
– Discharge a pyramidal neurons related to the position of the animal – Place Field is formed after few minutes and is stable for months – Rotation of external cues induce the rotation of place fields – A given place cell can have different place fields in different contexts
Internal representation of space in the hippocampus
Internal representation of space in the hippocampus
Contexte A Contexte B
time time
Neural bases of semantic memory
Quian Quiroga et al., Nat rev Neurosci
Quian Quiroga et al., Trends Cog Sci & Nat rev Neurosci
Sparse coding with cell assemblies or grandmother’s cell ?
(1) Probability to find the item selective for the recorded neuron is
- ne over 1 million
(2) Images already known by the subjects were used (3) Two million neurons represent a given percept over few hundred millions neurons in MTL (bayesian estimation) (4) One neuron could fire for different items.
Cell assemblies
Donald Hebb, The Organization of Behavior, 1949
"The general idea is an old one, that any two cells or systems of cells that are repeatedly active at the same time will tend to become 'associated', so that activity in one facilitates activity in the other." (p. 70) "When one cell repeatedly assists in firing another, the axon of the first cell develops synaptic knobs (or enlarges them if they already exist) in contact with the soma of the second cell." (p. 63)
Assemblée cellulaire
"If the inputs to a system cause the same pattern of activity to occur repeatedly, the set
- f active elements constituting that pattern will become increasingly strongly
- interassociated. That is, each element will tend to turn on every other element and (with
negative weights) to turn off the elements that do not form part of the pattern. To put it another way, the pattern as a whole will become 'auto-associated'. We may call a learned (auto-associated) pattern an engram." (p. 44) Donald Hebb, The Organization of Behavior, 1949
(d’après Bi & Poo 1998)
Spike 'ming dependent plas'city Cell assemblies: synchroniza'on within 'me period compa'ble with STDP
synchronization
Synchroniza'on & cell assemblies
synchronization
Synchroniza'on & cell assemblies
global noise local noise claping period Average noise intensity correlation
Neda et al Nature 2000
Cell assemblies, rhythms and the binding problem
Cell assemblies synchronization and the binding problem
Cell assemblies synchronization and the binding problem
Cell assemblies synchronization and the binding problem
"This situation was instantaneously and radically changed by a historical event, the symposium on visual perception at the Society for Neuroscience meeting in Washington, DC, in the fall of 1993. I have never seen so many neuroscientists attending any lecture on any topic of neuroscience than at that milestone
- event. ... After a long vacuum in systems research, a radicaly different and
comprehensive theory was on the horizon.The protagonist of the symposium was Wolf Singer from the Max-Planck Institute in Frankfurt- am-Main, Germany." György Buzsáki, Rhythms of the brain
Wolf Singer
Cell assemblies synchronization and the binding problem
Cell 1 Cell 2 Synchronisation ???
Cell assemblies synchronization and the binding problem
if you’re interested, read this…
« It needs still to be clarified, however, if the temporal code could solve the riddles of perceptual grouping. As things are at present, the binding problem reflects at least three correlated subquestions: (1) the segmentation of a complex visual scene, or figure- ground segregation; (2) the integration of a single perceptual object as from its components, and (3) the recognition of an object in spite of its variation in position, size, perspective, etc. » « An important aspect of this hypothesis, is that for the first time in the history of neuroscience, it has accounted for perceptual processes without invoking the idea of a superior area or center, where all processed information would converge. Accordingly, the fallacy of the homunculus (a torment for philosophers à la Daniel Dennett [51]) would be exorcised forever. » « For reasons largely unresolved until now, it appeared difficult to replicate in some laboratories the seminal results reported by Wolf Singer and his colleagues at the Max-Planck-Institute for Brain Research in Frankfurt, and by Reinhard Eckhorn and his group at the Philipps- University in
- Marburg. Some critical observations, moved by Martin Tovée and Edmund Rolls [16, 17] and by
Geoffrey Ghose and Ralph Freeman [18] in 1992, deserve particular attention in this context: either oscillations were not found in the visual cortex, or if they were, they appeared to be rhythmic responses not correlated to the stimulus. »
Delta waves - Delta rhythm(s)
Deep Sup
Pfc
Deep Sup
Par Cx
Deep Sup
Aud Cx Aud Th Hpc
Delta waves - Delta rhythm(s)
Deep Sup
Pfc
Deep Sup
Par Cx
Deep Sup
Aud Cx Aud Th Hpc
* * * * * * * * * *
Delta waves - Delta rhythm(s)
Theta oscillations
INTERNEURONS PYRAMIDAL CELLS
Theta oscillations
Theta
π 2π π 2π
π 2π
Modulation of hippocampal neurons by theta
Pyramidal neurons
Interneurones
25-30 classes of interneurons
Cellular types within the hippocampus
Modulation of hippocampal neurons by theta
Somogyi and Klauberger, Science, 2008
Theta oscillations
Rhythm generator
Vertes et al 2004
medial septum inactivation
EC3 CA1 CA3 EC5 DG EC2 Current generator
Current generator
Coupling theta - Gamma
Cross-frequency coupling
INTERNEURONS PYRAMIDAL CELLS
INTERNEURONS PYRAMIDAL CELLS
INTERNEURONS PYRAMIDAL CELLS
INTERNEURONS PYRAMIDAL CELLS
INTERNEURONS PYRAMIDAL CELLS
Geisler PNAS 2008
Köning et al. TINS 1996
Rate coding “Integrator” Temporal coding “Coincidence detector” Importance of Rhythms: Temporal versus rate coding
threshold AP 5me
Importance of Rhythms: Temporal versus rate coding
threshold AP 5me
Importance of Rhythms: Temporal versus rate coding
threshold AP 5me
Importance of Rhythms: Temporal versus rate coding
threshold AP 5me
rythmical inhibi4on
Gilles Laurent (olfactory system in locust)
Importance of Rhythms: Temporal versus rate coding
Inhibition could act by a non intuitive way …
Schreiber J Neurophy 2004
Schreiber J Neurophy 2004
93
What are the experimental evidences of the importance of rhythms
94
Phase
0° 360° 180°
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Phase
0° 360° 180°
Modulation of hippocampal neurons by theta: Phase precession
Phase
0° 360° 180°
Modulation of hippocampal neurons by theta: Phase precession
Phase
0° 360° 180°
Modulation of hippocampal neurons by theta: Phase precession
Phase
0° 360° 180°
Phase precession
O'Keefe et Recce 1993 Modulation of hippocampal neurons by theta: Phase precession
The phase of spikes improves their spatial information content
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
Modulation of hippocampal neurons by theta: Phase precession
In a theta cycle: where I was, where I am, where I am going. Temporal compression of sequence in time delays compatible with STDP
Modulation of hippocampal neurons by theta: Phase precession
(d’après Bi & Poo 1998)
Spike 'ming dependent plas'city Cell assemblies: synchroniza'on within 'me period compa'ble with STDP
In a theta cycle: where I was, where I am, where I am going. Temporal compression of sequence in time delays compatible with STDP
Modulation of hippocampal neurons by theta: Phase precession
Robbe & Buzsaki J Neurosci 2009