| Models | Description |
1. |
3D model of the olfactory bulb (Migliore et al. 2014)
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This entry contains a link to a full HD version of movie 1 and the NEURON code of the paper:
"Distributed organization of a brain microcircuit analysed by three-dimensional modeling: the olfactory bulb" by M Migliore, F Cavarretta, ML Hines, and GM Shepherd. |
2. |
A computational model of oxytocin modulation of olfactory recognition memory (Linster & Kelsch 2019)
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Model of olfactory bulb (OB) and anterior olfactory nucleus (AON) pyramidal cells. Includes olfactory sensory neurons, mitral cells, periglomerular, external tufted and granule interneurons and pyramidal cells. Can be built to include a feedback loop between OB and AON. Output consists of voltage and spikes over time in all neurons. Model can be stimulated with simulated odorants. The code submitted here has served for a number of modeling explorations of olfactory bulb and cortex.
The model architecture is defined in "bulb.dat" with synapses defined in "channels.dat". The main function to run the model can be found in "neuron.c". Model architecture is constructed in "set.c" from types defined in "sim.c". A make file to create an executable is located in "neuron.mak". |
3. |
A network of AOB mitral cells that produces infra-slow bursting (Zylbertal et al. 2017)
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Infra-slow rhythmic neuronal activity with very long (> 10 s) period duration was described in many brain areas but little is known about the role of this activity and the mechanisms that produce it. Here we combine experimental and computational methods to show that synchronous infra-slow bursting activity in mitral cells of the mouse accessory olfactory bulb (AOB) emerges from interplay between intracellular dynamics and network connectivity. In this novel mechanism, slow intracellular Na+ dynamics endow AOB mitral cells with a weak tendency to burst, which is further enhanced and stabilized by chemical and electrical synapses between them. Combined with the unique topology of the AOB network, infra-slow bursting enables integration and binding of multiple chemosensory stimuli over prolonged time scale.
The example protocol simulates a two-glomeruli network with a single shared cell. Although each glomerulus is stimulated at a different time point, the activity of the entire population becomes synchronous (see paper Fig. 8) |
4. |
AOB mitral cell: persistent activity without feedback (Zylbertal et al., 2015)
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Persistent activity has been reported in many brain areas and is
hypothesized to mediate working memory and emotional brain states and
to rely upon network or biophysical feedback. Here we demonstrate a
novel mechanism by which persistent neuronal activity can be generated
without feedback, relying instead on the slow removal of Na+ from
neurons following bursts of activity. This is a realistic
conductance-based model that was constructed using the detailed
morphology of a single typical accessory olfactory bulb (AOB) mitral
cell for which the electrophysiological properties were
characterized. |
5. |
Calcium and potassium currents of olfactory bulb juxtaglomerular cells (Masurkar and Chen 2011)
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Inward and outward currents of the olfactory bulb juxtaglomerular cells are characterized in the experiments and modeling in these two Masurkar and Chen 2011 papers. |
6. |
Cellular and Synaptic Mechanisms Differentiate Mitral & Superficial Tufted Cells (Jones et al 2020)
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"To evaluate how... different electrophysiological aspects contributed to spiking of the output MCs and sTCs, we used computational modeling. By exchanging the different cell properties in our modeled MCs and sTCs, we could evaluate each property's contribution to spiking differences between these cell types. This analysis suggested that the higher sensitivity of spiking in sTCs vs. MCs reflected both their larger monosynaptic OSN signal as well as their higher input resistance, while their smaller prolonged currents had a modest opposing effect. Taken together, our results indicate that both synaptic and intrinsic cellular features contribute to the production of parallel output channels in the olfactory bulb." |
7. |
Coincident signals in Olfactory Bulb Granule Cell spines (Aghvami et al 2019)
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"In the mammalian olfactory bulb, the inhibitory axonless granule cells (GCs) feature reciprocal synapses that interconnect them with the principal neurons of the bulb, mitral, and tufted cells. These synapses are located within large excitable spines that can generate local action potentials (APs) upon synaptic input (“spine spike”). Moreover, GCs can fire global APs that propagate throughout the dendrite. Strikingly, local postsynaptic Ca2+ entry summates mostly linearly with Ca2+ entry due to coincident global APs generated by glomerular stimulation, although some underlying conductances should be inactivated. We investigated this phenomenon by constructing a compartmental GC model to simulate the pairing of local and global signals as a function of their temporal separation ?t. These simulations yield strongly sublinear summation of spine Ca2+ entry for the case of perfect coincidence ?t = 0 ms. ..." |
8. |
Emergence of Connectivity Motifs in Networks of Model Neurons (Vasilaki, Giugliano 2014)
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Recent evidence suggests that short-term dynamics of excitatory synaptic transmission is correlated to stereotypical connectivity motifs.
We show that these connectivity motifs emerge in networks of model neurons, from the interactions between short-term synaptic dynamics (SD) and long-term spike-timing dependent plasticity (STDP). |
9. |
Functional structure of mitral cell dendritic tuft (Djurisic et al. 2008)
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The computational modeling component of Djurisic et al. 2008 addressed two primary questions: whether amplification by active currents is necessary to explain the relatively mild attenuation suffered by tuft EPSPs spreading along the primary dendrite to the soma; what accounts for the relatively uniform peak EPSP amplitude throughout the tuft. These simulations show that passive spread from tuft to soma is sufficient to yield the low attenuation of tuft EPSPs, and that random distribution of a biologically plausible number of excitatory synapses throughout the tuft can produce the experimentally observed uniformity of depolarization.
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10. |
Gamma-beta alternation in the olfactory bulb (David, Fourcaud-Trocmé et al., 2015)
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This model, a simplified olfactory bulb network with mitral and granule cells, proposes a framework for two regimes of oscillation in the olfactory bulb:
1 - a weak inhibition regime (with no granule spike) where the network oscillates in the gamma (40-90Hz) band
2 - a strong inhibition regime (with granule spikes) where the network oscillates in the beta (15-30Hz) band.
Slow modulations of sensory and centrifugal inputs, phase shifted by a quarter of cycle, possibly combined with short term depression of the mitral to granule AMPA synapse, allows the network to alternate between the two regimes as observed in anesthetized animals. |
11. |
Infraslow intrinsic rhythmogenesis in a subset of AOB projection neurons (Gorin et al 2016)
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We investigated patterns of spontaneous neuronal activity in mouse accessory olfactory bulb mitral cells, the direct neural link between vomeronasal sensory input and limbic output. Both in vitro and in vivo, we identify a subpopulation of mitral cells that exhibit slow stereotypical rhythmic discharge. In intrinsically rhythmogenic neurons, these periodic activity patterns are maintained in absence of fast synaptic drive. The physiological mechanism underlying mitral cell autorhythmicity involves cyclic activation of three interdependent ionic conductances: subthreshold persistent Na(+) current, R-type Ca(2+) current, and Ca(2+)-activated big conductance K(+) current. Together, the interplay of these distinct conductances triggers infraslow intrinsic oscillations with remarkable periodicity, a default output state likely to affect sensory processing in limbic circuits. The model reproduces the intrinsic firing in a reconstructed single AOB mitral cell with ion channels kinetics fitted to experimental measurements of their steady state and time course. |
12. |
Large scale model of the olfactory bulb (Yu et al., 2013)
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The readme file currently contains links to the results for all the 72 odors investigated in the paper, and the movie showing the network activity during learning of odor k3-3 (an aliphatic ketone).
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13. |
Lateral dendrodenditic inhibition in the Olfactory Bulb (David et al. 2008)
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Mitral cells, the principal output neurons of the olfactory bulb, receive direct synaptic activation from primary sensory neurons. Shunting inhibitory inputs delivered by granule cell interneurons onto mitral cell lateral dendrites are believed to influence spike timing and underlie coordinated field potential oscillations. Lateral dendritic shunt conductances delayed spiking to a degree dependent on both their electrotonic distance and phase of onset. Recurrent inhibition significantly narrowed the distribution of mitral cell spike times, illustrating a tendency towards coordinated synchronous activity. This result suggests an essential role for early mechanisms of temporal coordination in olfaction. The model was adapted from Davison et al, 2003, but include additional noise mechanisms, long lateral dendrite, and specific synaptic point processes. |
14. |
Mitral cell activity gating by respiration and inhibition in an olfactory bulb NN (Short et al 2016)
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To explore interactions between respiration, inhibition, and olfaction,
experiments using light to active channel rhodopsin in sensory neurons expressing Olfactory Marker Protein were performed in mice and modeled in silico.
This archive contains NEURON models that were run on parallel computers to explore the interactions between varying strengths of respiratory activity and olfactory sensory neuron input and the roles of periglomerular, granule, and external tufted cells in shaping mitral cell responses. |
15. |
Na+ Signals in olfactory bulb neurons (granule cell model) (Ona-Jodar et al. 2017)
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Simulations of Na+ during action potentials in granule cells replicated the behaviors observed in experiments. |
16. |
Neurogenesis in the olfactory bulb controlled by top-down input (Adams et al 2018)
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This code implements a model for adult neurogenesis of granule cells in the olfactory system. The granule cells receive sensory input via the mitral cells and top-down input from a cortical area. That cortical area also receives olfactory input from the mitral cells as well as contextual input. This plasticity leads to a network structure consisting of bidirectional connections between bulbar and cortical odor representations. The top-down input enhances stimulus discrimination based on contextual input. |
17. |
Olfactory bulb cluster formation (Migliore et al. 2010)
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Functional roles of distributed synaptic clusters in the mitral-granule cell network of the olfactory bulb. |
18. |
Olfactory bulb juxtaglomerular models (Carey et al., 2015)
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" ...We investigated how OB circuits shape inhalation-driven
dynamics in MCs using a modeling approach that was highly constrained by experimental
results. First, we constructed models of canonical OB circuits that included mono- and disynaptic
feedforward excitation, recurrent inhibition and feedforward inhibition of the MC. We then used
experimental data to drive inputs to the models and to tune parameters; inputs were derived from
sensory neuron responses during natural odorant sampling (sniffing) in awake rats, and model
output was compared to recordings of MC responses to odorants sampled with the same sniff
waveforms. This approach allowed us to identify OB circuit features underlying the temporal
transformation of sensory inputs into inhalation-linked patterns of MC spike output.
..." |
19. |
Olfactory bulb microcircuits model with dual-layer inhibition (Gilra & Bhalla 2015)
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A detailed network model of the dual-layer dendro-dendritic inhibitory microcircuits in the rat olfactory bulb comprising compartmental mitral, granule and PG cells developed by Aditya Gilra, Upinder S. Bhalla (2015).
All cell morphologies and network connections are in NeuroML v1.8.0. PG and granule cell channels and synapses are also in NeuroML v1.8.0. Mitral cell channels and synapses are in native python. |
20. |
Olfactory bulb mitral and granule cell column formation (Migliore et al. 2007)
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In the olfactory bulb, the processing units for odor discrimination are believed
to involve dendrodendritic synaptic interactions between mitral and granule cells.
There is increasing anatomical evidence that these cells are organized in columns,
and that the columns processing a given odor are arranged in widely distributed arrays.
Experimental evidence is lacking on the underlying learning mechanisms for how these
columns and arrays are formed.
We have used a simplified realistic circuit model to test the hypothesis that
distributed connectivity can self-organize through an activity-dependent dendrodendritic
synaptic mechanism.
The results point to action potentials propagating in the mitral cell lateral dendrites
as playing a critical role in this mechanism, and suggest a novel and robust learning
mechanism for the development of distributed processing units in a cortical structure.
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21. |
Olfactory bulb mitral and granule cell: dendrodendritic microcircuits (Migliore and Shepherd 2008)
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This model shows how backpropagating action potentials in the long lateral dendrites of mitral cells, together with granule cell actions on mitral cells within narrow columns forming glomerular units, can provide a mechanism to activate strong local inhibition between arbitrarily distant mitral cells. The simulations predict a new role for the dendrodendritic synapses in the multicolumnar organization of the granule cells. |
22. |
Olfactory bulb mitral cell gap junction NN model: burst firing and synchrony (O`Connor et al. 2012)
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In a network of 6 mitral cells connected by gap junction in the apical dendrite tuft, continuous current injections of 0.06 nA are injected into 20 locations in the apical tufts of two of the mitral cells. The current injections into one of the cells starts 10 ms after the other to generate asynchronous firing in the cells (Migliore et al. 2005 protocol). Firing of the cells is asynchronous for the first 120 ms. However after the burst firing phase is completed the firing in all cells becomes synchronous. |
23. |
Olfactory bulb mitral cell: synchronization by gap junctions (Migliore et al 2005)
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In a realistic model of two electrically connected mitral cells,
the paper shows that the somatically-measured experimental properties
of Gap Junctions (GJs) may correspond to a variety of different local coupling strengths
and dendritic distributions of GJs in the tuft. The model suggests
that the propagation of the GJ-induced local tuft depolarization
is a major mechanim for intraglomerular synchronization of mitral cells. |
24. |
Olfactory Bulb mitral-granule network generates beta oscillations (Osinski & Kay 2016)
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This model of the dendrodendritic mitral-granule synaptic network generates gamma and beta oscillations as a function of the granule cell excitability, which is represented by the granule cell resting membrane potential. |
25. |
Olfactory Bulb Network (Davison et al 2003)
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A biologically-detailed model of the mammalian olfactory bulb, incorporating
the mitral and granule cells and the dendrodendritic synapses between them.
The results of simulation experiments with electrical stimulation agree
closely in most details with published experimental data. The model predicts
that the time course of dendrodendritic inhibition is dependent on the
network connectivity as well as on the intrinsic parameters of the synapses.
In response to simulated odor stimulation, strongly activated mitral cells
tend to suppress neighboring cells, the mitral cells readily synchronize
their firing, and increasing the stimulus intensity increases the degree of
synchronization. For more details, see the reference below. |
26. |
Olfactory bulb network model of gamma oscillations (Bathellier et al. 2006; Lagier et al. 2007)
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This model implements a network of 100 mitral cells connected with
asynchronous inhibitory "synapses" that is meant to reproduce the
GABAergic transmission of ensembles of connected granule cells.
For appropriate parameters of this special synapse the model generates
gamma oscillations with properties very similar to what is observed
in olfactory bulb slices (See Bathellier et al. 2006, Lagier et al. 2007).
Mitral cells are modeled as single compartment neurons with a small
number of different voltage gated channels. Parameters were tuned to reproduce the
fast subthreshold oscillation of the membrane potential observed experimentally
(see Desmaisons et al. 1999).
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27. |
Olfactory bulb network: neurogenetic restructuring and odor decorrelation (Chow et al. 2012)
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Adult neurogenesis in the olfactory bulb has been shown experimentally
to contribute to perceptual learning. Using a computational network
model we show that fundamental aspects of the adult neurogenesis
observed in the olfactory bulb -- the persistent addition of new
inhibitory granule cells to the network, their activity-dependent
survival, and the reciprocal character of their synapses with the
principal mitral cells -- are sufficient to restructure the network
and to alter its encoding of odor stimuli adaptively so as to reduce
the correlations between the bulbar representations of similar
stimuli. The model captures the experimentally observed
role of neurogenesis in perceptual learning and the enhanced response
of young granule cells to novel stimuli. Moreover, it makes specific
predictions for the type of odor enrichment that should be effective
in enhancing the ability of animals to discriminate similar odor
mixtures. NSF grant DMS-0719944.
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28. |
Olfactory Computations in Mitral-Granule cell circuits (Migliore & McTavish 2013)
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Model files for the entry "Olfactory Computations in Mitral-Granule Cell Circuits" of the Springer Encyclopedia of Computational Neuroscience by Michele Migliore and Tom Mctavish.
The simulations illustrate two typical Mitral-Granule cell circuits in the olfactory bulb of vertebrates: distance-independent lateral inhibition and gating effects.
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29. |
Online learning model of olfactory bulb external plexiform layer network (Imam & Cleland 2020)
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This model illustrates the rapid online learning of odor representations, and their recognition despite high levels of interference (other competing odorants), in a model of the olfactory bulb external plexiform layer (EPL) network. The computational principles embedded in this model are based on the those developed in the biophysical models of Li and Cleland (2013, 2017).
This is a standard Python version of a model written for Intel's Loihi neuromorphic hardware platform (The Loihi code is available at https://github.com/intel-nrc-ecosystem/models/tree/master/official/epl). |
30. |
Parallel odor processing by mitral and middle tufted cells in the OB (Cavarretta et al 2016, 2018)
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"[...] experimental findings suggest that
MC and mTC may encode parallel and complementary odor representations. We
have analyzed the functional roles of these pathways by using a morphologically
and physiologically realistic three-dimensional model to explore the MC and
mTC microcircuits in the glomerular layer and deeper plexiform layers. [...]"
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31. |
Self-organized olfactory pattern recognition (Kaplan & Lansner 2014)
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" ...
We present a large-scale network model with single and multi-compartmental Hodgkin–Huxley type model neurons representing olfactory receptor neurons (ORNs) in the epithelium, periglomerular cells, mitral/tufted cells and granule cells in the olfactory bulb (OB), and three types of cortical cells in the piriform cortex (PC).
Odor patterns are calculated based on affinities between ORNs and odor stimuli derived from physico-chemical descriptors of behaviorally relevant real-world odorants.
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The PC was implemented as a modular attractor network with a recurrent connectivity that was likewise organized through Hebbian–Bayesian learning.
We demonstrate the functionality of the model in a one-sniff-learning and recognition task on a set of 50 odorants.
Furthermore, we study its robustness against noise on the receptor level and its ability to perform concentration invariant odor recognition. Moreover, we investigate the pattern completion capabilities of the system and rivalry dynamics for odor mixtures." |
32. |
Synchrony by synapse location (McTavish et al. 2012)
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This model considers synchrony between mitral cells induced via shared
granule cell interneurons while taking into account the spatial
constraints of the system. In particular, since inhibitory inputs
decay passively along the lateral dendrites, this model demonstrates
that an optimal arrangement of the inhibitory synapses will be near
the cell bodies of the relevant mitral cells. |
33. |
Theoretical reconstrucion of field potentials and dendrodendritic synaptic...(Rall & Shepherd 1968)
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This
was the first application of compartmental modeling using the Rall
approach to brain neurons. It combined multicompartmental representation
of a mitral cell and a granule cell with the first Hodgkin-Huxley-like
action potential
to model antidromic activation of the mitral cell, followed by synaptic
excitation of the granule cell and synaptic inhibition of the mitral cell.
Combined with reconstruction of the field
potentials generated around these neurons, and detailed comparisons with
single
cell recordings, it led to prediction of dendrodendritic interactions
mediating
self and lateral inhibition of the mitral cells by the granule cells. It
has been regarded as
the first computational model of a brain microcircuit (see also Shepherd
and Brayton, 1979). Recreation of the model is pending. |
34. |
Voltage imaging calibration in tuft dendrites of mitral cells (Djurisic et al 2004)
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A detailed morphology of a tuft is provided in a reconstruction of a mitral cell that was used to place simulated estimates on for the calibration of EPSPs as recorded in voltage imaging in the real cells (estimated to be within +12% to -18% of the actual amplitude). |