Fig 1.
Setup for awake ERG/VEP recording.
A, B, Images of the device used to fix the skull of a mouse while recording awake ERGs and VEPs. C, Experimental setup for recording. A mouse with head fixed to the restraint device was placed on a rotatable polystyrene cylinder. The setup allows the mouse to run or walk freely during ERG/VEP recording. Electrical cords, which are not shown in the image, were connected to the electrodes on the skull during recording. D, An adaptor, a nut, and a bolt used to connect a mouse to the vertical attachment of the restraint device (red arrows in panels A, B, and C). The ends of the adaptor linked the mouse skull to the restraint device and platform. E, Screw electrode, fixation bolt, and wire electrode implants: 1, reference wire electrode for ERG; 2, reference screw electrode for VEP; 3, 4, positive screw electrodes for VEP; 5, plastic bolt used to attach the skull to the fixation device (see blue arrows in panels C and E); asterisk, bregma.
Fig 2.
Awake and anesthetized ERG from the same mice.
A. Representative traces of scotopic (top) and photopic (bottom) ERGs recorded from the same mouse in the awake (left) and anesthetized (right) condition. B. Amplitudes of scotopic (top) and photopic (bottom) ERG waves from the same mice recorded in awake (black) and anesthetized (red) conditions. C. Implicit times of scotopic (top) and photopic (bottom) ERG waves from the same mice recorded in awake (black) and anesthetized (red) conditions. * P < 0.05. Data from seven mice. The bars indicate mean ± standard error of the mean (S.E.M). anes: anesthetized.
Fig 3.
Comparison of OPs extracted from ERGs acquired under awake and anesthetized conditions.
Representative ERG traces before and after the extraction of OPs from a scotopic ERG (0 log cd s/m2). Schematic illustration showing the amplitude (an) and implicit time (tn) of each OP wavelet (OPn). C, D. Amplitudes (C) and implicit times (D) of individual OP wavelets (OP1–OP4) recorded in the awake (black) and anesthetized (red) condition from the same mice. E, F. Summed amplitudes (C) and implicit times (D) of all OP wavelets (OP1–OP4) from ERGs recorded under awake (black) and anesthetized (red) conditions from the same mice. * P < 0.05. Data from seven mice. The bars indicate mean ± S.E.M. anes: anesthetized.
Fig 4.
Comparison of VEPs recorded under awake and anesthetized conditions in the same mice.
Representative traces of scotopic (top) and photopic (bottom) VEPs from the same mouse recorded in the awake (left) and anesthetized (right) condition. Amplitudes of scotopic (top) and photopic (bottom) VEPs from the same mice recorded in the awake (black) and anesthetized (red) condition. Implicit times of scotopic (top) and photopic (bottom) ERGs from the same mice recorded in the awake (black) and anesthetized (red) condition. * P < 0.05. Data from seven mice. The bars indicate mean ± S.E.M. anes: anesthetized.
Fig 5.
Stability of the ERG and VEP recording.
A, B, Amplitude time courses of ERG and VEP waveforms recorded in anesthetized mice (N = 4 for each time point). The flashes (0 log cd/m2) were given in the scotopic condition. The bars indicate mean ± S.E.M.