Orientation and direction selectivity in the visual cortex Selectivity to sound frequency in the auditory cortex Feature selectivity in the somatosensory system Orientation selectivity in the primary visual cortex ID: 1038579
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1. Mechanisms of stimulus feature selectivity in sensory systemsOrientation and direction selectivity in the visual cortexSelectivity to sound frequency in the auditory cortex Feature selectivity in the somatosensory system.
2. Orientation selectivity in the primary visual cortexThe Nobel Prize in Physiology or Medicine 1981
3. Orientation selectivity in the primary visual cortexHubel and Wiesel experimentsThe H&W model – a simple feedforward modelPredictions of the H&W modelMismatches between H&W model and experimental dataRecurrent models for orientation selectivityExperiments that support the H&W – intracellular recording dataAdvanced imaging experiments and the H&W model Optogenetic manipulations of specific types of neuronsRecent studies on orientation selectivity in mouse visual cortex
4. Orientation selectivity
5. Receptive fields in the retinaOn and Off centers are important to generate reliable output signal (firing) in ganglion cellsThe transmission between cones and bipolar cells depends on the type (on vs off) target type Note:mGluR6 is metabotropic and leads to hyperpolarization of the bipolar cell AMPA and Kinate are ionotropic and have excitatory effect on bipolar cellsOff = Sign conservingOn = Sign InvertingBipolar cells are:
6. Receptive fields in V1, H&W experimentsThalamic cells Cortical cells Cortical cells ‘Simple cells’
7. Data from H&W experiments: flashing bars : “complex cell”
8. H&W model for simple cells
9. Hubel and Wiesel, 1962The Feedforward ModelLGNCortical Simple cellH&W model:
10. H&W model for complex cells
11. H&W model for simple cells
12. H&W model for complex cells
13. Visual cortex cell
14. Binacularity
15. Hubel and Wiesel, 1962The Feedforward ModelLGNCortical Simple cellHubel and Wiesel model
16. Predictions of the H&W model for simple cells do not match the dataMajor Failures of the FF model of H&W:Contrast invarianceCross-orientation suppressionMismatch of receptive field maps and orientation tuningMissing response at the null orientationPharmacology: blocking GABA(a) causes widening of TC.
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18. Predictions of the H&W model for simple cells do not match the dataThe model predicts narrowing of the TC as contrast increases !Actual data: the tuning curves show contrast invariance
19. Predictions of the H&W model for simple cells: actual data
20. Predictions of the H&W model:Failure 2: cross-orientation suppression
21. Predictions of the H&W model:Failure 3: Mismatch of receptive field maps and orientation tuningGardner et al. 1999Extracellular data
22. The relation between the structure of the receptive field and orientation selectivityThe predicted curveMeasured curve from Spikes
23. Hubel and Wiesel, 1962The Feedforward ModelLGNCortical Simple cellPredictions of the H&W model:Failure 4: Missing response at the null orientationThat the V1 cells barely respond to null orientation is puzzling given the fact that the AVERAGE activation of thalamic cells is the same, regardless the orientation of the stimulus
24. Hubel and Wiesel, 1962The Feedforward ModelLGNCortical Simple cellPredictions of the H&W model:Failure 4: Missing response at the null orientationThe response at the null direction is low (i.e., lack of DC response even when looking at membrane potential level.
25. Predictions of the H&W model:Failure 5: PharmacolgyThe effect of bicuculline , antagonist of GABA(A), on the TC of V1 cellsSillito 1975
26. Predictions of the H&W model:Failure 5: PharmacolgySillito et al. 1980Bicucullin caused widening of the tuning curves, suggesting that inhibition shapes the TC of the cells
27. Excitatory and inhibitory recurrent models for orientation selectivitySomers et al. 1995
28. Role of inhibition in orientation selectivity:Lateral inhibition: inhibition suppresses the response more in non-preferred orientations and thus narrowing the TC at high contrasts Somers et al. 1995
29. Recurrent models for orientation selectivitySomers et al. 1995There are two processes that sharpen thalamic inputs and allow contrast invariance:Lateral inhibition at non-preferred orientationsAmplification of thalamic inputs by recurrent excitatory connectionsPrediction: the width of TC inhibition should be wider than for excitation TCWe will see if this is true later…
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31. Experiments that support the H&W – intracellular recording data. The role of noise in contrast invarianceContrast invarianceAnderson et al. 2000
32. Experiments that support the H&W – intracellular recording data. The role of noise in contrast invarianceContrast invariancePriebe and Ferster 2012
33. Experiments that support the H&W :The role of noise in contrast invarianceContrast invariancePriebe and Ferster 2012
34. Experiments that support the H&W – measurements of sensory evoked conductance in-vivo2. TC of excitatory and inhibitory inputsHeiss et al. 2008Synaptic current Ei ~= -80 mVEe~ = 0 mV
35. Experiments that support the H&W – Excitatory and inhibitory inputs have similar TCHence: inhibition is unlikely to sharpen thalamic inputs 2. TC of excitatory and inhibitory inputsAnderson et al. 2000orientationPrediction from recurrent models:*The width of inhibition TC is not wider than for excitation
36. Experiments that support the H&W – Mismatch of receptive field maps and orientation tuning.Intracellular data show why TC and RF do not match at spikes level - this is because of the iceberg effect. At Vm level they nicely matchLampl et al. 2001Spikes dataVm data
37. Experiments that support the H&W – Mismatch of receptive field maps and orientation tuning.Intracellular data show why TC and RF do not match at spikes level - this is because of the iceberg effect. At Vm level they nicely matchPriebe and Ferster 2012
38. Experiments that support the H&W – Cross-orientation suppressionPriebe and Ferster 2012
39. Experiments that support the H&W – Cross-orientation suppressionPriebe and Ferster 2012
40. Experiments that support the H&W:New insights on the pharmacological effects on TC Katzner et al. 2011
41. Experiments that support the H&W:New insights on the pharmacological effects on TC – the iceberg effect Katzner et al. 2011
42. Different types of cortical inhibitory cells in cortexPV – parvalbuminNG - Neurogliaform VIP – Vasoactive intestinal peptideSOM- somatostatin
43. Two Photon (2P) Imaging and optogenetic studies of the visual cortex Contrast invarianceWilson et al. 2012Divisive Subtraction
44. Optogenetic studies of the visual cortex Contrast invarianceAttalah et al. 2012
45. Recurrent models for orientation selectivityIssacoson and Scanziani 2011
46. Optogenetic studies of the visual cortex Lien and Scanziani, 2013To find the tuning of thalamic inputs they silenced cortical firing while patching layer 4 cells of V1Conclusion: about 1/3 of E in cortex comes from thalamic input, the other 2/3 is due to recurrent amplification of these input by cortical cells.
47. Cortical circuits amplify tuned thalamic inputs without altering orientation selectivity
48. Cortical circuits amplify tuned thalamic inputs without altering orientation selectivityThe TCs of cortical inputs are similar to the TCs of thalamic inputs
49. Direction selectivity in V1From H&H
50. Direction selectivity in V1Lien and Scanziani 2018Intracortical TC ConvergenceRetina
51. Direction selectivity in V1Lien and Scanziani 2018Isolation of thalamic inputs of L4 cells in PV-ChR2 cells (cortical silencing) Thalamic input is also direction selective!
52. Direction selectivity in V1Static stimulation at different spatial phases shows that TC component of DS cells exhibits two components:fast decaying response (eEPSP) and late (slow) response (lEPSP) and in non-DS there is only one type of response. Thalamic input is also direction selective!
53. Direction selectivity in V1Simulation of summation (different phases)
54. Direction selectivity in V1Recordings in thalamus with cortical recordings. Two types of TC cells: 1) transient firing at certain phases (blue unit). 2) sustain firing at other phases (red unit).
55. Direction selectivity in V1Model of thalamo-cortical convergence for DS of cortical cells.
56. Auditory cortex – Excitation and inhibition are co-tuned to sound intensity and frequencyInhibition?Wehr and Zador 2003Voltage clamp experiments of A1 neuronsInhibitionExcitation
57. Li et al, 2014Auditory cortex – Excitation and inhibition are co-tuned to sound intensity and frequencyAWAKE MICE
58. Adaptation of excitation and inhibition in barrel cortexHeiss et al. 2008restInhibition adapts faster and to greater degree than excitation
59. Selectivity to direction of whisker deflectionWilent and Contreras 2005
60. Selectivity to direction of whisker deflection:Excitation but not inhibition is selectiveWilent and Contreras 2005
61. Selectivity to direction of whisker deflection:Response to preferred direction is NMDA dependent Lavzin et al. 2012
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63. Auditory cortex – lateral suppressionInhibition?Sutter et al. 1999
64. Auditory cortex – Excitation and inhibition are co-tuned to sound intensity and frequencyInhibition?Wehr and Zador 2003