Lecture 4 - Prey Capture PDF

Lecture 4 - Prey capture Sign stimuli and release mechanisms Remember PollEverywhere Image taken from Fabulous Frogs, Nature series  Lecture 4 Announcements Reviews - exercise, intra- vs. extra-cellular, and last lecture Escape circuits - curre...

Lecture 4 - Prey capture Sign stimuli and release mechanisms Remember PollEverywhere Image taken from Fabulous Frogs, Nature series  Lecture 4 Announcements Reviews - exercise, intra- vs. extra-cellular, and last lecture Escape circuits - current papers Prey capture  Announcements If you schedule an office hour timeslot - please respect it Office hours can be virtual Grade discussions always in person Short essay answers should be short Please engage on Piazza  Class exercise review Design an experiment that tests one sign stimulus and one evoked behaviour Test only one feature of the stimulus No aids or notes are permitted Use the scientific method You are allowed to work together Try to concretely imagine performing the experiment We are here to help  Weekly quiz The authors claim that the neurons responsible for this behavioural response are most likely cells from the OFF pathway with transient responses. What are the subplots which support this claim, and how is the claim supported by the presented data? Intracellular Features Predicted by Extracellular Recordings in the Hippocampus In Vivo DARRELL A. HENZE, ZSOLT BORHEGYI, JOZSEF CSICSVARI, AKIRA MAMIYA, KENNETH D. HARRIS, AND GY ̈ORGY BUZSAKI  Intracellular Features Predicted by Extracellular Recordings in the Hippocampus In Vivo Entire extracellular Filtered extracellular Current injection Signal transduction - Sensilla recordings Tuthill, Current Biology, 2016  Recap Recording methods Intracellular Extracellular Electrode makes contact Recording from extracellular with the inside of the cell space (close to cell) Can record subthreshold Can detect mainly spikes activity Current injections (but will affect the surrounding cells Allows for filling and also) clamping Does not damage cell Invasive and disrupts the membrane cell EPSP, IPSP and spikes are neuronal responses and are independent from techniques Image from CNS tech lab EPSP, IPSP and spikes are neuronal responses and are independent from techniques Image from CNS tech lab EPSP, IPSP and spikes are neuronal responses and are independent from techniques Image from CNS tech lab  Crayfish tail flip Role of inhibition Prevents concurrent activation prevents persistent excitation of antagonistic muscle of own muscle Inhibitory synapse Excitatory synapse Electrical synapse Escape response Loom detectors Escape response Loom detectors  Looming research in Locust Gabbiani, J Neuroscience 1999  How to understand this plot Gabbiani, J Neuroscience 1999  How to understand this plot Gabbiani, J Neuroscience 1999  How to understand this plot Gabbiani, J Neuroscience 1999  How to understand this plot Raster plot Gabbiani, J Neuroscience 1999  How to understand this plot Estimated instantaneous firing rate Gabbiani, J Neuroscience 1999  How to understand this plot Gabbiani, J Neuroscience 1999  How to understand this plot Gabbiani, J Neuroscience 1999  How to understand this plot Gabbiani, J Neuroscience 1999  How to understand this plot Gabbiani, J Neuroscience 1999  How to understand this plot Gabbiani, J Neuroscience 1999  Looming research in Locust Gabbiani, J Neuroscience 1999 Drosophila looming response A tale of two modes Drosophila looming response A tale of two modes Drosophila looming response A tale of two modes  How to read a scientific paper - Understanding methods and controls Image: Ache, Curr. Bio. 2019  Drosophila looming response Von Ryen, Nat. Neurosci. 2014  Drosophila looming response GF is a descending neuron Von Ryen, Nat. Neurosci. 2014  Gal4/UAS system Gal4 - yeast transcription activator with no similarity in flies UAS - upstream activation sequence Gal4 binds specifically to UAS and induces transcription Gal4 controls where UAS controls what Figure: Kelly, JOVE, 2017  Split Gal4 Splits the Gal4 protein into 2 parts AD - activation domain DBD - DNA binding domain Provides even higher specificity for where Figure: Rubin lab, Janelia  Split Gal4 Splits the Gal4 protein into 2 parts AD - activation domain DBD - DNA binding domain Provides even higher specificity for where Figure: Rubin lab, Janelia  Kir 2.1 K - potassium ir - inward rectifying Over expression of the channel clamps cells and prevents activation Effectively silences cells  Drosophila looming response Von Ryen, Nat. Neurosci. 2014  Drosophila looming response Kir2.1 Channelrhodopsin Von Ryen, Nat. Neurosci. 2014  Drosophila looming response Kir2.1 Channelrhodopsin Von Ryen, Nat. Neurosci. 2014  Drosophila looming response Kir2.1 Channelrhodopsin Channelrhodopsin Light gated ion channel Von Ryen, Nat. Neurosci. 2014 Linking GF activity to behaviour  Showing behavioural relevance in naturalistic conditions r/v GF- Kir2.1 expressed in GF neuron  Prey capture Sign stimuli and release mechanisms Image taken from Fabulous Frogs, Nature series Toads hunting Prey capture in frogs Barlow, J Physiol. 1953  Neuron’s receptive field First applied to neurons that are Retinal Ganglion Cells Lettvin, Proceedings of the IRE, 1959 Spillmann, Perception 2014  Neuron’s receptive field Receptive field recordings in frogs Recorded before the micro-electrodes Dissected frog retina Moved a small dot of light Hartline, Ame. J. of Physiolo. 1940 with varying intensity “No description of the optic responses in single fibers would be complete without a description of the region of the retina, which must be illuminated in order to obtain a response in any given fiber. This region will be termed the receptive field of the fiber.”  Neuron’s receptive field Center surround receptive field In OFF fibres increasing stimulus size increased response In ON-OFF fibres, after a certain size there is a reduction in response Barlow suggested ‘surround inhibition’ and ‘fly detectors’ Barlow, J. Physiol. 1953  Neuron’s receptive field Center surround receptive field ON centre OFF centre Spillmann, Perception 2014 cell cell Neuron’s receptive field Receptive fields in the Cat’s visual cortex Hubel & Wiesel - Cortical Neuron - V1 Neuron’s receptive field Receptive fields in the Cat’s visual cortex Hubel & Wiesel - Cortical Neuron - V1 Why didn’t the neuron spike? Why didn’t the neuron spike?  Back to frog prey capture Reasons to work on frogs Uniform retina No fovea or high acuity region Eye and head movements are only compensatory Stabilising retinal image Retina projects only to Colliculus In mammals also to Cortex (through LGN) Simple stimuli evoke predictable behaviour consistently  Toad prey capture What do we know about the behaviour? Stimulus Behaviour  Toad prey capture What do we know about the behaviour? Stimulus Behaviour Small insect moves in the Orienting movement visual periphery  Toad prey capture What do we know about the behaviour? Stimulus Behaviour Small insect moves in the Orienting movement visual periphery Insect fixated in the front Approach  Toad prey capture What do we know about the behaviour? Stimulus Behaviour Small insect moves in the Orienting movement visual periphery Insect fixated in the front Approach Insect within striking Lunging and tongue distance extension  Toad prey capture What do we know about the behaviour? Stimulus Behaviour Small insect moves in the Orienting movement visual periphery Insect fixated in the front Approach Insect within striking Lunging and tongue distance extension Swallowing Mouth wiping  Design an experiment Assess the importance of the sign stimulus for a particular behaviour What assay would you use? What parameters would you change in the stimulus? What aspect will you measure in the behaviour?  Required reading What the frog’s eye tell the frog’s brain Lettvin, Proceedings of the IRE, 1959 Note reading instructions - no need to read the whole paper. Please answer the question concisely. How does the toad’s brain define ‘prey’? And where does it happen? Jörg-Peter Ewert Leader in neuroethological studies of toad releasing mechanisms  How does the toad’s brain define ‘prey’? Adapted from Nerve cells and animal behaviour  How does the toad’s brain define ‘prey’? Adapted from Nerve cells and animal behaviour  How does the toad’s brain define ‘prey’? Adapted from Nerve cells and animal behaviour  How does the toad’s brain define ‘prey’? Adapted from Nerve cells and animal behaviour Direction of motion  How does the toad’s brain define ‘prey’? Adapted from Nerve cells and animal behaviour Direction of motion  How does the toad’s brain define ‘prey’? Adapted from Nerve cells and animal behaviour Direction of motion  How does the toad’s brain define ‘prey’? Adapted from Nerve cells and animal behaviour Direction of motion  How does the toad’s brain define ‘prey’? Adapted from Nerve cells and animal behaviour Direction of motion  How does the toad’s brain define ‘prey’? Adapted from Nerve cells and animal behaviour Direction of motion  How does the toad’s brain define ‘prey’? Worm Anti-worm Adapted from Nerve cells and animal behaviour Direction of motion Neuroethology of Toads (Part 1 of 3; English): Behavioral Responses to Prey Features Neuroethology of Toads (Part 1 of 3; English): Behavioral Responses to Prey Features  Two basic processes are required for orienting responses: the identi cation of the stimulus the identi cation of its location in space. Identi cation determines what behaviour will be produced Detection localises the stimulus Together determine the motor response Ewart Scr. American 1974 fi fi fi  Recordings from RGCs in toads Nerve cells and animal behaviour  Recordings from RGCs in toads Nerve cells and animal behaviour  Recordings from RGCs in toads Nerve cells and animal behaviour  Recordings from RGCs in toads Nerve cells and animal behaviour  Neuronal recordings Ewert Animal Behaviour 1985  Recordings from RGCs in toads Nerve cells and animal behaviour  Recordings from RGCs in toads Nerve cells and animal behaviour  Recordings from RGCs in toads Nerve cells and animal behaviour  Recordings from RGCs in toads Nerve cells and animal behaviour  Recordings from RGCs in toads Does not match behaviour Nerve cells and animal behaviour  Where is the “worm” feature detected? The Toad’s visual circuit Optic tectum: midbrain region that contains ~7 retinoreceipent nuclei. Most RGCs project here Thalamus: kind of like the hub of information in the vertebrate brain. Retinotopy Mapping of visual space in the Retina Neuronal response in the visual circuit Neuronal response in the visual circuit Approach Avoidance Electrical stimulation Electrical stimulation Tectal  Electrical stimulation Thalamic/Pretectal Tectal  Evidence for optic tectum - thalamic connections  Evidence for optic tectum - thalamic connections Thalamic neurons (sensitive to motion) respond to point stimulation in Tectum  Evidence for optic tectum - thalamic connections Thalamic neurons (sensitive to motion) respond to point stimulation in Tectum Responses of Type II neurons in Tectum are inhibited by Thalamus stimulation  Evidence for optic tectum - thalamic connections Thalamic neurons (sensitive to motion) respond to point stimulation in Tectum Responses of Type II neurons in Tectum are inhibited by Thalamus stimulation Optic tectum surgically removed - no orienting or avoidance  Evidence for optic tectum - thalamic connections Thalamic neurons (sensitive to motion) respond to point stimulation in Tectum Responses of Type II neurons in Tectum are inhibited by Thalamus stimulation Optic tectum surgically removed - no orienting or avoidance Thalamus removed - more stimuli elicit orienting responses Consequences of Thalamic removal Consequences of Thalamic removal Behavioural Consequences of Thalamic removal Behavioural Consequences of Thalamic removal Electrophysiological Consequences of Thalamic removal Electrophysiological Neuroethology of Toads (Part 2 of 3; English) Feature Detecting Nerve Cells in the Brain Neuroethology of Toads (Part 2 of 3; English) Feature Detecting Nerve Cells in the Brain  Behavioural response as a result of a series of filters Simplified view Inhibitory synapse Ewert, Sci. American, 1974  Behavioural response as a result of a series of filters Simplified view Inhibitory synapse Orient towards Ewert, Sci. American, 1974  Behavioural response as a result of a series of filters Simplified view Inhibitory synapse Do not orient Orient towards Ewert, Sci. American, 1974  Response modulation Bright on dark background evokes stronger orienting response than dark on bright In the winter this preference is reversed Found RGCs that show this reversal In winter, overall prey catching behaviour is reduced  Prey-Capture Behaviour in Zebrafish Portugues, Curr. Op. Neuobio, 2009  Prey-Capture Behaviour in Zebrafish Portugues, Curr. Op. Neuobio, 2009 Prey-Capture Behaviour in Zebrafish Introduction What is known What is the question What was found What is the significance Fovea-like Photoreceptor Specializations Underlie Single UV Cone Driven Prey-Capture Behavior in Zebrafish Yoshimatsu, et al., Neuron, 2020 In vision, photoreceptors drive the retinal network through continuous modulations in synaptic release. However, how changes in incoming photon flux lead to changes in the rate of vesicle fusion at the synapse varies dramatically between photoreceptor designs. For example, in the vertebrate retina, the slow rod photoreceptors typically have large outer segments and high-gain intracellular signaling cascades to deliver single-photon sensitivity critical for vision at low light. In contrast, cone photoreceptors are faster and have smaller outer segments and lower-gain cascades to take over where rods saturate. Fovea-like Photoreceptor Specializations Underlie Single UV Cone Driven Prey-Capture Behavior in Zebrafish Yoshimatsu, et al., Neuron, 2020 Clearly, matching the properties of a given photoreceptor type to a specific set of sensory tasks critically underpins vision. However, these visual requirements can differ dramatically across the retinal surface and the corresponding position in visual space.For efficient sampling, even cones of a single type must therefore be functionally tuned depending on their retinal location. Indeed, photoreceptor tuning, even within type, is a fundamental property of vision in both invertebrates and vertebrates. Even primates make use of this trick; foveal cones have longer integration times than their peripheral counterparts, likely to boost their signal to noise ratio, as in the foveal center, retinal ganglion cells (RGCs) do not spatially pool their inputs. Understanding the mechanisms that underlie such functional tuning will be important for understanding how sensory systems can operate in the natural sensory world and how they might have evolved to suit new sensory-ecological niches. Fovea-like Photoreceptor Specializations Underlie Single UV Cone Driven Prey-Capture Behavior in Zebrafish Yoshimatsu, et al., Neuron, 2020 Here, we show that UV cones in the area temporalis (‘‘strike zone’’ [SZ]) of larval zebrafish are selectively tuned to detect microorganisms that these animals feed on (e.g., paramecia) Larval Zebrafish Prey Capture Must Use UV Vision Show prey more prominent in UV channel Larval Zebrafish Prey Capture Must Use UV Vision Test behavioural responses  Single UV Cones May Signal the Presence of Prey Use known UV receptor distribution combined with behavioural results UV Cone-Outer Segment Size Varies More Than 10-fold across the Eye To increase photon absorption efficiency where needed most SZ UV Cones Are Light Biased and Have a High Gain and Long Integration Times SyGCaMP6f synaptically tagged fluorescent calcium biosensor mCherry expressed under same promoter non-synaptically localised fluorescent protein SZ UV Cones Are Light Biased and Have a High Gain and Long Integration Times SyGCaMP6f synaptically tagged fluorescent calcium biosensor mCherry expressed under same promoter non-synaptically localised fluorescent protein syGCaMP6f Chasing down a tool syGCaMP6f Chasing down a tool syGCaMP6f Chasing down a tool syGCaMP6f Chasing down a tool syGCaMP6f Chasing down a tool syGCaMP6f Chasing down a tool syGCaMP6f Chasing down a tool syGCaMP6f Chasing down a tool Wikipedia  Methods ROI detection - maximise SNR Pre-processing Regions of interest (ROIs), corresponding to individual presynaptic terminals of UV- cones were defined automatically based on local thresholding of the recording stack’s s.d. projection over time (s.d. typically > 25), followed by filtering for size and shape using custom written software on IGOR Pro 6.3 (Wavemetrics). Specifically, only round ROIs (< 150% elongation) of size 2-5 µm2 were further analyzed.  Methods ROI detection - maximise SNR Pre-processing Regions of interest (ROIs), corresponding to individual presynaptic terminals of UV- cones were defined automatically based on local thresholding of the recording stack’s s.d. projection over time (s.d. typically > 25), followed by filtering for size and shape using custom written software on IGOR Pro 6.3 (Wavemetrics). Specifically, only round ROIs (< 150% elongation) of size 2-5 µm2 were further analyzed.  Methods ROI detection - maximise SNR Pre-processing Regions of interest (ROIs), corresponding to individual presynaptic terminals of UV- cones were defined automatically based on local thresholding of the recording stack’s s.d. projection over time (s.d. typically > 25), followed by filtering for size and shape using custom written software on IGOR Pro 6.3 (Wavemetrics). Specifically, only round ROIs (< 150% elongation) of size 2-5 µm2 were further analyzed.  Methods ROI detection - maximise SNR Pre-processing Regions of interest (ROIs), corresponding to individual presynaptic terminals of UV- cones were defined automatically based on local thresholding of the recording stack’s s.d. projection over time (s.d. typically > 25), followed by filtering for size and shape using custom written software on IGOR Pro 6.3 (Wavemetrics). Specifically, only round ROIs (< 150% elongation) of size 2-5 µm2 were further analyzed.  Methods Z-normalization - correct intensity differences Pre-processing Calcium traces for each ROI were extracted and z- normalized based on the time interval 1-6 s at the beginning of recordings prior to presentation of systematic light stimulation. x−μ μ = mean z= σ σ = S.D SZ UV Cones Are Light Biased Increased light sensitivity SZ UV Cones Are Light Biased Increased light sensitivity Exponential decay time constant −t/τ N(t) = N0e N0 = 10 τ=1 τ=2 τ=5 Exponential decay Initial quantity −t/τ N(t) = N0e τ=1 N0 = 10 N0 = 5 N0 = 1 SZ UV Cones are slow to recover from a light flash Larger integration window Slow recovery from light flash Fast recovery from dark flash  Discussion Summary and open questions  Discussion Summary and open questions Behaviourally, zebrafish only respond if the prey moves  Discussion Summary and open questions Behaviourally, zebrafish only respond if the prey moves How can motion be detected by a single receptor?  Discussion Summary and open questions Behaviourally, zebrafish only respond if the prey moves How can motion be detected by a single receptor? Raise the problem of studying zebrafish behaviour in the lab under UV deficient conditions  Discussion Summary and open questions Behaviourally, zebrafish only respond if the prey moves How can motion be detected by a single receptor? Raise the problem of studying zebrafish behaviour in the lab under UV deficient conditions Connection between UV cones activation and the prey-capture circuit  Discussion Summary and open questions Behaviourally, zebrafish only respond if the prey moves How can motion be detected by a single receptor? Raise the problem of studying zebrafish behaviour in the lab under UV deficient conditions Connection between UV cones activation and the prey-capture circuit The region-specific differences in UV cone function present the first pre- processing steps to detect prey and predators already at the visual system’s first synapse