TY - JOUR

T1 - Luminance Changes Drive Directional Startle through a Thalamic Pathway

AU - Heap, Lucy A.L.

AU - Vanwalleghem, Gilles

AU - Thompson, Andrew W.

AU - Favre-Bulle, Itia A.

AU - Scott, Ethan K.

N1 - Funding Information: We thank Misha Ahrens for the elavl3:H2B:GCaMP6f line and Thomas R. Scott for guidance. Support came from an NHMRC project grant ( APP1066887 ), an Australian Research Council future fellowship ( FT110100887 ), a grant from the Simons Foundation ( SFARI 399432 ), and two Australian Research Council grants ( DP140102036 and DP110103612 ) (to E.K.S.); an EMBO long-term fellowship (ALTF 727-2014 to G.V.); and Australian postgraduate awards (to A.W.T. and L.A.L.H.). We used the Queensland Brain Institute’s Advanced Microscopy Facility, supported by an Australian Research Council LIEF grant ( LE130100078 ), and support was provided by the Australian National Fabrication Facility (ANFF) Queensland node. Funding Information: We thank Misha Ahrens for the elavl3:H2B:GCaMP6f line and Thomas R. Scott for guidance. Support came from an NHMRC project grant (APP1066887), an Australian Research Council future fellowship (FT110100887), a grant from the Simons Foundation (SFARI 399432), and two Australian Research Council grants (DP140102036 and DP110103612) (to E.K.S.); an EMBO long-term fellowship (ALTF 727-2014 to G.V.); and Australian postgraduate awards (to A.W.T. and L.A.L.H.). We used the Queensland Brain Institute's Advanced Microscopy Facility, supported by an Australian Research Council LIEF grant (LE130100078), and support was provided by the Australian National Fabrication Facility (ANFF) Queensland node. Publisher Copyright: © 2018 Elsevier Inc.

PY - 2018/7/25

Y1 - 2018/7/25

N2 - Looming visual stimuli result in escape responses that are conserved from insects to humans. Despite their importance for survival, the circuits mediating visual startle have only recently been explored in vertebrates. Here we show that the zebrafish thalamus is a luminance detector critical to visual escape. Thalamic projection neurons deliver dim-specific information to the optic tectum, and ablations of these projections disrupt normal tectal responses to looms. Without this information, larvae are less likely to escape from dark looming stimuli and lose the ability to escape away from the source of the loom. Remarkably, when paired with an isoluminant loom stimulus to the opposite eye, dimming is sufficient to increase startle probability and to reverse the direction of the escape so that it is toward the loom. We suggest that bilateral comparisons of luminance, relayed from the thalamus to the tectum, facilitate escape responses and are essential for their directionality. Animals from insects to humans escape from looming visual stimuli. With calcium imaging in larval zebrafish, we show that the thalamus detects a drop in luminance as a simulated predator approaches, directing an appropriate escape movement away from the predator.

AB - Looming visual stimuli result in escape responses that are conserved from insects to humans. Despite their importance for survival, the circuits mediating visual startle have only recently been explored in vertebrates. Here we show that the zebrafish thalamus is a luminance detector critical to visual escape. Thalamic projection neurons deliver dim-specific information to the optic tectum, and ablations of these projections disrupt normal tectal responses to looms. Without this information, larvae are less likely to escape from dark looming stimuli and lose the ability to escape away from the source of the loom. Remarkably, when paired with an isoluminant loom stimulus to the opposite eye, dimming is sufficient to increase startle probability and to reverse the direction of the escape so that it is toward the loom. We suggest that bilateral comparisons of luminance, relayed from the thalamus to the tectum, facilitate escape responses and are essential for their directionality. Animals from insects to humans escape from looming visual stimuli. With calcium imaging in larval zebrafish, we show that the thalamus detects a drop in luminance as a simulated predator approaches, directing an appropriate escape movement away from the predator.

KW - calcium imaging

KW - GCaMP

KW - selective plane illumination microscopy

KW - SPIM

KW - superior colliculus

KW - tectum

KW - thalamus

KW - vision

KW - visual escape

KW - zebrafish

UR - http://www.scopus.com/inward/record.url?scp=85049111900&partnerID=8YFLogxK

U2 - 10.1016/j.neuron.2018.06.013

DO - 10.1016/j.neuron.2018.06.013

M3 - Journal article

C2 - 29983325

AN - SCOPUS:85049111900

VL - 99

SP - 293-301.e4

JO - Neuron

JF - Neuron

SN - 0896-6273

IS - 2

ER -