DOI: 10.5061/dryad.c2fqz61f2
title: Calcium imaging data from: Functional organization of visual responses in the octopus optic lobe

description: Cephalopods are highly visual animals with camera-type eyes, large brains,
 and a rich repertoire of visually guided behaviors. However, the
 cephalopod brain evolved independently from that of other highly visual
 species, such as vertebrates, and therefore the neural circuits that
 process sensory information are profoundly different. It is largely
 unknown how their powerful but unique visual system functions, since there
 have been no direct neural measurements of visual responses in the
 cephalopod brain. In this study, we used two-photon calcium imaging to
 record visually evoked responses in the primary visual processing center
 of the octopus central brain, the optic lobe, to determine how basic
 features of the visual scene are represented and organized. We found
 spatially localized receptive fields for light (ON) and dark (OFF)
 stimuli, which were retinotopically organized across the optic lobe,
 demonstrating a hallmark of visual system organization shared across many
 species. Examination of these responses revealed transformations of the
 visual representation across the layers of the optic lobe, including the
 emergence of the OFF pathway and increased size selectivity. We also
 identified asymmetries in the spatial processing of ON and OFF stimuli,
 which suggest unique circuit mechanisms for form processing that may have
 evolved to suit the specific demands of processing an underwater visual
 scene. This study provides insight into the neural processing and
 functional organization of the octopus visual system, highlighting both
 shared and unique aspects, and lays a foundation for future studies of the
 neural circuits that mediate visual processing and behavior in
 cephalopods.
description: Calcium imaging was performed with a two-photon microscope
 (Neurolabware Inc.), using a 16X Nikon CFI75 LWD objective, via the
 Scanbox software package for Matlab (MATHWORKS). Data were acquired at a
 10Hz framerate, with an 800x800μm (796x796 pixel) field of view.
 Recordings were taken at 90 to 170μm depths from the dorsal surface of the
 optic lobe.  Custom generated visual stimuli, rendered using the
 PsychToolbox package for Matlab72, were displayed with a pico LCD
 projector (AAXA Technologies) onto the diffusing glass on the side of the
 recording chamber. To avoid light from the stimulus entering the
 two-photon detection pathway, the projected light was passed through a
 450/50 bandpass filter (Chroma Technology Corporation), avoiding overlap
 with the emission spectrum of the Cal-520 calcium dye and the bandpass
 525/50 emission filter of the microscope. The stimulus bandpass filter
 also restricted the stimulus light to be within the known absorption
 spectrum of cephalopod photopigments26. Stimuli were gamma-corrected in
 software and presented at 60FPS.  Full RF mapping was performed using a
 sparse noise stimulus, consisting of white and black spots (radius = 3, 6,
 12 deg; density = 10%) on a gray (50% luminance) background, along with
 full-field white or black on 2% of frames. Each stimulus frame was
 presented for 1sec in a randomized order for a total duration of
 10min. Data analysis was performed using custom
 software in MATLAB. We applied a rigid alignment of imaging data using the
 sbxalign function in Scanbox (Neurolabware, Inc.). In order to detect
 large movements that were not corrected by the alignment algorithm, for
 each frame we calculated the pixel-wise correlation coefficient to the
 mean image. Frames with less that 90% correlation were discarded from
 further analyses.  We calculated the fluorescence
 activity (dF/F0) at each pixel as the standard (F(t) - F0) / F0, where
 F(t) is the fluorescence intensity of the pixel on each frame and F0 is
 the median fluorescence intensity of the pixel across the recording. To
 analyze local responses, we defined “units” as a 20μmx20μm wide square
 window, centered on local peaks within the mean fluorescence that were
 above the background fluorescence, to ensure that only areas with
 sufficient dye loading were analyzed. dF/F0 for each unit was calculated
 as the mean dF/F0 across pixels within the unit. Units were manually
 assigned to anatomical layers (OGL, IGL, Plex, and Med) based on location
 within the mean fluorescence image from the recording session.
description: Data files are in Matlab .mat format, which is based on HDF5 and
 is readable across languages.
description: # Calcium imaging data from Pungor et al 2023, Functional organization of
 visual responses in the octopus optic lobe *** This dataset contains
 calcium imaging data from the octopus optic lobe, measured during
 presentation of a sparse noise stimulus. The data files include dF/F
 traces for all identified units and associated receptive fields and size
 tuning curve traces. ## Description of the Data and file structure **6
 imaging sessions** PungorCB\_073019\_dataset.mat
 PungorCB\_080819\_dataset.mat PungorCB\_082219\_dataset.mat
 PungorCB\_100219\_dataset.mat PungorCB\_100719\_dataset.mat
 PungorCB\_100919\_dataset.mat **Variables for each session**
 *stimFrames*(movieFrame) onset of each movie frame, in acquisition frames
 *dF*(unit,frame) dF/F0 for each unit extracted, on each acq frame
 *xpts*(units), ypts(unit) x,y pixel location of each unit
 *stas*(x,y,unit,on/off) 2-D STA receptive field for each unit, for ON and
 OFF components *rfx*(unit,on/off), *rfy*(unit,on/off) x and y location of
 receptive field peak for each unit, for ON and OFF components
 *zscore*(unit, on/off) z-score of RF peak for each unit, for ON and OFF
 components *tuning*(unit, on/off, size, t) response timecourse for each
 unit for ON,OFF at 4 sizes (3,6,12deg, full) *xb*{layer}, *yb*{layer}
 boundary points demarcating region of each layer in the image
 *moviedata*(x,y,frame) sparse noise stimulus **Notes:** Imaging framerate
 = 10Hz Stimulus framerate = 1Hz Pixel size = 2um/pixel ## Sharing/access
 Information Links to other publicly accessible locations of the data: n/a
 Was data derived from another source? No