lecture 12: olfaction: the insect antennal lobe references: h c mulvad, thesis (mulvad/thesis), ch...
TRANSCRIPT
![Page 1: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/1.jpg)
Lecture 12: olfaction: the insect antennal lobe
References:H C Mulvad, thesis (http://www.nordita.dk/~mulvad/Thesis), Ch 2G Laurent, Trends Neurosci 19 489-496 (1996)M Bazhenov et al, Neuron 30 553-567 and 569-581 (2001)Dayan & Abbott, Sect 7.5
![Page 2: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/2.jpg)
Olfaction (smell)
![Page 3: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/3.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
![Page 4: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/4.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
Highly conserved in evolution (mammals and insects similar)
![Page 5: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/5.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
Highly conserved in evolution (mammals and insects similar)
Basic anatomy:
![Page 6: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/6.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
Highly conserved in evolution (mammals and insects similar)
Basic anatomy:Insects: receptor cells -> antennal lobe -> mushroom bodies
![Page 7: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/7.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
Highly conserved in evolution (mammals and insects similar)
Basic anatomy:Insects: receptor cells -> antennal lobe -> mushroom bodiesMammals: receptor cells -> olfactory bulb -> olfactory cortex
![Page 8: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/8.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
Highly conserved in evolution (mammals and insects similar)
Basic anatomy:Insects: receptor cells -> antennal lobe -> mushroom bodiesMammals: receptor cells -> olfactory bulb -> olfactory cortex
~100000 receptor cells, several hundred types (distinguished by receptor proteins)
![Page 9: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/9.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
Highly conserved in evolution (mammals and insects similar)
Basic anatomy:Insects: receptor cells -> antennal lobe -> mushroom bodiesMammals: receptor cells -> olfactory bulb -> olfactory cortex
~100000 receptor cells, several hundred types (distinguished by receptor proteins)any cell responsive to a range of odorants:
![Page 10: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/10.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
Highly conserved in evolution (mammals and insects similar)
Basic anatomy:Insects: receptor cells -> antennal lobe -> mushroom bodiesMammals: receptor cells -> olfactory bulb -> olfactory cortex
~100000 receptor cells, several hundred types (distinguished by receptor proteins)any cell responsive to a range of odorants: => an odor produces a characteristic pattern of activity
across the receptor cell population
![Page 11: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/11.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
Highly conserved in evolution (mammals and insects similar)
Basic anatomy:Insects: receptor cells -> antennal lobe -> mushroom bodiesMammals: receptor cells -> olfactory bulb -> olfactory cortex
~100000 receptor cells, several hundred types (distinguished by receptor proteins)any cell responsive to a range of odorants: => an odor produces a characteristic pattern of activity
across the receptor cell population
Receptor physiology: Receptor proteins (1 kind/cell): metabotropic, G-protein coupled,
lead to opening of Na channels
![Page 12: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/12.jpg)
Olfaction (smell)The oldest sense (even bacteria do it)
Highly conserved in evolution (mammals and insects similar)
Basic anatomy:Insects: receptor cells -> antennal lobe -> mushroom bodiesMammals: receptor cells -> olfactory bulb -> olfactory cortex
~100000 receptor cells, several hundred types (distinguished by receptor proteins)any cell responsive to a range of odorants: => an odor produces a characteristic pattern of activity
across the receptor cell population
Receptor physiology: Receptor proteins (1 kind/cell): metabotropic, G-protein coupled,
lead to opening of Na channels, similar to phototransductionin retina
![Page 13: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/13.jpg)
Antennal lobe~1000-10000 neurons
in locust: 1130: 830 excitatory, 300 inhibitoryin honeybee: 800 excitatory, 4000 inhibitory
![Page 14: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/14.jpg)
Antennal lobe~1000-10000 neurons
in locust: 1130: 830 excitatory, 300 inhibitoryin honeybee: 800 excitatory, 4000 inhibitory
Organized into glomeruli (bunches of synapes) (~1000 in locust, 160 in bee)
![Page 15: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/15.jpg)
Antennal lobe~1000-10000 neurons
in locust: 1130: 830 excitatory, 300 inhibitoryin honeybee: 800 excitatory, 4000 inhibitory
Organized into glomeruli (bunches of synapes) (~1000 in locust, 160 in bee)
![Page 16: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/16.jpg)
Antennal lobe~1000-10000 neurons
in locust: 1130: 830 excitatory, 300 inhibitoryin honeybee: 800 excitatory, 4000 inhibitory
Organized into glomeruli (bunches of synapes) (~1000 in locust, 160 in bee)
Connections between ALneurons: dendrodentritic
![Page 17: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/17.jpg)
Excitatory cells (PN)PN = projection neuron: axon takes its spikes out of the antennal
lobe, to the mushroom bodies (+ other higher areas)
![Page 18: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/18.jpg)
Excitatory cells (PN)PN = projection neuron: axon takes its spikes out of the antennal
lobe, to the mushroom bodies (+ other higher areas) transmitter: ACh
![Page 19: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/19.jpg)
Excitatory cells (PN)PN = projection neuron: axon takes its spikes out of the antennal
lobe, to the mushroom bodies (+ other higher areas) transmitter: ACh
![Page 20: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/20.jpg)
Excitatory cells (PN)PN = projection neuron: axon takes its spikes out of the antennal
lobe, to the mushroom bodies (+ other higher areas) transmitter: ACh
Dendrites have postsynaptic terminalsin 1 or more glomeruli
(10-20 in locust)
![Page 21: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/21.jpg)
Inhibitory cells (LN)LN = local neuron: projects only within the antennal lobe
![Page 22: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/22.jpg)
Inhibitory cells (LN)LN = local neuron: projects only within the antennal lobe
no Na spikes, only Ca “spikelets”
![Page 23: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/23.jpg)
Inhibitory cells (LN)LN = local neuron: projects only within the antennal lobe
no Na spikes, only Ca “spikelets”transmitter: GABA
![Page 24: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/24.jpg)
Inhibitory cells (LN)LN = local neuron: projects only within the antennal lobe
no Na spikes, only Ca “spikelets”transmitter: GABA
![Page 25: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/25.jpg)
Inhibitory cells (LN)LN = local neuron: projects only within the antennal lobe
no Na spikes, only Ca “spikelets”transmitter: GABA
Dendrites with postsynaptic terminals in several or all glomeruli
![Page 26: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/26.jpg)
Antennal lobe responses:temporally modulated oscillatory activity patterns
![Page 27: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/27.jpg)
Antennal lobe responses:temporally modulated oscillatory activity patterns
~20 hz oscillations:
![Page 28: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/28.jpg)
Antennal lobe responses:temporally modulated oscillatory activity patterns
(No oscillations in input from receptor cells)
~20 hz oscillations:
![Page 29: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/29.jpg)
Oscillations and transient synchronization
membrane potentials
![Page 30: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/30.jpg)
Oscillations and transient synchronization
membrane potentials
Local field potentialIn mushroom body:Measures averageAL activity
(cell in mushroom body)
![Page 31: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/31.jpg)
Oscillations and transient synchronization
membrane potentials
Local field potentialIn mushroom body:Measures averageAL activity
PN firing transientlysynchronized toLFP
(cell in mushroom body)
![Page 32: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/32.jpg)
Model (Bazhenov et al)
• 90 PNs, 30 LNs
![Page 33: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/33.jpg)
Model (Bazhenov et al)
•90 PNs, 30 LNs
•Single-compartment, conductance-based neurons
![Page 34: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/34.jpg)
Model (Bazhenov et al)
•90 PNs, 30 LNs
•Single-compartment, conductance-based neurons
•(post)synaptic kinetics
![Page 35: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/35.jpg)
Model (Bazhenov et al)
•90 PNs, 30 LNs
•Single-compartment, conductance-based neurons
•(post)synaptic kinetics
•Fast excitation, fast and slow inhibition
![Page 36: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/36.jpg)
Model (Bazhenov et al)
•90 PNs, 30 LNs
•Single-compartment, conductance-based neurons
•(post)synaptic kinetics
•Fast excitation, fast and slow inhibition
•50% connectivity, random
![Page 37: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/37.jpg)
Model (Bazhenov et al)
•90 PNs, 30 LNs
•Single-compartment, conductance-based neurons
•(post)synaptic kinetics
•Fast excitation, fast and slow inhibition
•50% connectivity, random
•Stimuli: 1-s current pulse inputs to randomly-chosen 33% of neurons
![Page 38: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/38.jpg)
Bazhenov network
![Page 39: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/39.jpg)
Excitatory neurons
stimsynAKNaLL IIIIIVVgdtdV
C )(
![Page 40: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/40.jpg)
Excitatory neurons
stimsynAKNaLL IIIIIVVgdtdV
C )(
Active currents:
![Page 41: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/41.jpg)
Excitatory neurons
stimsynAKNaLL IIIIIVVgdtdV
C )(
)(3NaNaNa VVhmgI
Active currents:Na
![Page 42: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/42.jpg)
Excitatory neurons
stimsynAKNaLL IIIIIVVgdtdV
C )(
)(3NaNaNa VVhmgI )(4 KKK VVngI
Active currents:Na K
![Page 43: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/43.jpg)
Excitatory neurons
stimsynAKNaLL IIIIIVVgdtdV
C )(
)(3NaNaNa VVhmgI )(4 KKK VVngI )(4
KAAAA VVhmgI
Active currents:Na K A-current
![Page 44: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/44.jpg)
Excitatory neurons
stimsynAKNaLL IIIIIVVgdtdV
C )(
)(3NaNaNa VVhmgI )(4 KKK VVngI )(4
KAAAA VVhmgI
inhslowGABAnAChsyn IIIIA
Active currents:Na K A-current
Synaptic input
![Page 45: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/45.jpg)
Excitatory neurons
stimsynAKNaLL IIIIIVVgdtdV
C )(
)(3NaNaNa VVhmgI )(4 KKK VVngI )(4
KAAAA VVhmgI
inhslowGABAnAChsyn IIIIA
)]([ ssfast VVOgI
Active currents:Na K A-current
Synaptic input
Fast (ionotropic) synaptic currents (nACh and GABAA):
( [O] is open fraction)
![Page 46: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/46.jpg)
Excitatory neurons
stimsynAKNaLL IIIIIVVgdtdV
C )(
)(3NaNaNa VVhmgI )(4 KKK VVngI )(4
KAAAA VVhmgI
inhslowGABAnAChsyn IIIIA
)]([ ssfast VVOgI ][]])[[1(][
OTOdtOd
Active currents:Na K A-current
Synaptic input
Fast (ionotropic) synaptic currents (nACh and GABAA):
( [O] is open fraction)
[T] is transmitter concentration:
![Page 47: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/47.jpg)
Excitatory neurons
stimsynAKNaLL IIIIIVVgdtdV
C )(
)(3NaNaNa VVhmgI )(4 KKK VVngI )(4
KAAAA VVhmgI
inhslowGABAnAChsyn IIIIA
)]([ ssfast VVOgI ][]])[[1(][
OTOdtOd
]/))((exp[11
][
)()(][
0
0max0
VtVT
tttttAT
Active currents:Na K A-current
Synaptic input
Fast (ionotropic) synaptic currents (nACh and GABAA):
( [O] is open fraction)
[T] is transmitter concentration: exc
inh
![Page 48: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/48.jpg)
Slow inhibition
Kinetics like GABAB )(][][
4
4
Kslowinhslow VVKG
GgI
![Page 49: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/49.jpg)
Slow inhibition
Kinetics like GABAB )(][][
4
4
Kslowinhslow VVKG
GgI
][][][
43 GrRrdtGd G-protein concentration:
![Page 50: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/50.jpg)
Slow inhibition
Kinetics like GABAB )(][][
4
4
Kslowinhslow VVKG
GgI
][][][
43 GrRrdtGd
][]])[[1(][
21 RrTRrdtRd
G-protein concentration:
Activated receptor concentration
![Page 51: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/51.jpg)
Slow inhibition
Kinetics like GABAB )(][][
4
4
Kslowinhslow VVKG
GgI
][][][
43 GrRrdtGd
][]])[[1(][
21 RrTRrdtRd
G-protein concentration:
Activated receptor concentration
Fast and slowComponents:
![Page 52: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/52.jpg)
Inhibitory neurons
stimsynCaKKCaLL IIIIIVVgdtdV
C )()(
![Page 53: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/53.jpg)
Inhibitory neurons
stimsynCaKKCaLL IIIIIVVgdtdV
C )()(
Active currents:
![Page 54: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/54.jpg)
Inhibitory neurons
stimsynCaKKCaLL IIIIIVVgdtdV
C )()(
)(2CaCaCaCaCa VVhmgI
Active currents:Ca
![Page 55: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/55.jpg)
Inhibitory neurons
stimsynCaKKCaLL IIIIIVVgdtdV
C )()(
)(2CaCaCaCaCa VVhmgI
Active currents:Ca
( -> Ca spikes)
![Page 56: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/56.jpg)
Inhibitory neurons
stimsynCaKKCaLL IIIIIVVgdtdV
C )()(
)(2CaCaCaCaCa VVhmgI )(4 KKK VVngI
Active currents:Ca K
( -> Ca spikes)
![Page 57: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/57.jpg)
Inhibitory neurons
stimsynCaKKCaLL IIIIIVVgdtdV
C )()(
)(2CaCaCaCaCa VVhmgI )(4 KKK VVngI )()()()( KCaKCaKCaK VVngI
Active currents:Ca K Ca-dependent K current
( -> Ca spikes)
![Page 58: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/58.jpg)
Inhibitory neurons
stimsynCaKKCaLL IIIIIVVgdtdV
C )()(
)(2CaCaCaCaCa VVhmgI )(4 KKK VVngI )()()()( KCaKCaKCaK VVngI
Active currents:Ca K Ca-dependent K current
( -> spike rate adaptation)( -> Ca spikes)
![Page 59: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/59.jpg)
Inhibitory neurons
stimsynCaKKCaLL IIIIIVVgdtdV
C )()(
)(2CaCaCaCaCa VVhmgI )(4 KKK VVngI )()()()( KCaKCaKCaK VVngI
2][100
,2][][ )()(
CaCa
Can CaK
nCaK
Active currents:Ca K Ca-dependent K current
Dynamics of nK(Ca):
( -> spike rate adaptation)( -> Ca spikes)
![Page 60: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/60.jpg)
Inhibitory neurons
stimsynCaKKCaLL IIIIIVVgdtdV
C )()(
)(2CaCaCaCaCa VVhmgI )(4 KKK VVngI )()()()( KCaKCaKCaK VVngI
)][]([][ CaCa
IdtCad
Ca
2][100
,2][][ )()(
CaCa
Can CaK
nCaK
Active currents:Ca K Ca-dependent K current
Dynamics of nK(Ca):
Ca dynamics:
( -> spike rate adaptation)( -> Ca spikes)
![Page 61: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/61.jpg)
2 neurons (1 PN, 1LN)
![Page 62: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/62.jpg)
6 PNs + 2 LNs
![Page 63: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/63.jpg)
6 PNs + 2 LNs(fast) inhibition between LNs
![Page 64: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/64.jpg)
6 PNs + 2 LNs(fast) inhibition between LNs
![Page 65: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/65.jpg)
6 PNs + 2 LNs(fast) inhibition between LNs
LNs take turns:
![Page 66: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/66.jpg)
Full network (90+30)
![Page 67: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/67.jpg)
Responses of 4 PNs to 1 stimulus
![Page 68: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/68.jpg)
Responses of 4 PNs to 1 stimulus
Reliable (trial-to-trial reproducible) firing timing when there is largeInhibitory input
![Page 69: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/69.jpg)
Another stimulus:Input to same set of PNs but different LNs
![Page 70: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/70.jpg)
Another stimulus:Input to same set of PNs but different LNs
![Page 71: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/71.jpg)
Another stimulus:Input to same set of PNs but different LNs
Same overall firing rate pattern, but different temporal fine structure
![Page 72: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/72.jpg)
3rd stimulus:Input to 90%-different set of neurons:
![Page 73: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/73.jpg)
3rd stimulus:Input to 90%-different set of neurons:
![Page 74: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/74.jpg)
3rd stimulus:Input to 90%-different set of neurons:
Different firing pattern across neurons (but same network-average rate)
![Page 75: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/75.jpg)
Blocking LN-LN inhibitionLNs now spike ~ regularly
![Page 76: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/76.jpg)
Blocking LN-LN inhibitionLNs now spike ~ regularly
Less difference between responses to stimuli 1 and 2
![Page 77: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/77.jpg)
Reducing IK(Ca) (reducing LN spike-rate adaptation)
![Page 78: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/78.jpg)
Reducing IK(Ca) (reducing LN spike-rate adaptation)
![Page 79: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/79.jpg)
Reducing IK(Ca)
Less precise timing, weaker temporal modulation, reduced discriminability
(reducing LN spike-rate adaptation)
![Page 80: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/80.jpg)
Role of slow LN-PN inhibition
![Page 81: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/81.jpg)
Role of slow LN-PN inhibition
Slow rate modulationsabolished
![Page 82: Lecture 12: olfaction: the insect antennal lobe References: H C Mulvad, thesis (mulvad/Thesis), Ch 2mulvad/Thesis](https://reader036.vdocuments.us/reader036/viewer/2022062407/56649cc65503460f9498fbd6/html5/thumbnails/82.jpg)
Role of slow LN-PN inhibition
Slow rate modulationsabolished
reduced discriminability