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Purpose
Full-field electroretinogram (ERG) is a mass electrical response of the retina to a light stimulus. The ERG contains two components, reflecting the response of the photoreceptors (a-wave) and ON bipolar cells (b-wave; Kofujj et al., 2000 J Neurosci 20: 5733-5740, 2000)
Experimental Design
Procedure
- Transfer mice from animal room 4435 to the testing room 4435C
- Mice are weighed, and 1 drop of Atropine is placed in right eye (unless eye is missing, small, or otherwise effected) to induce mydriasis.
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Place mice in dark adaption chamber.
- All rod testing procedures are done under dim red light after 2 hour dark adaptation
- Ketaset/Xylazine /saline solution (0.1ml/20g body weight) is injected (i.p.) to induce anesthesia and 1 drop of Cyclomydril (ophthalmic solutions) are applied to induce mydriasis.
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Once the pupil has dilated and anesthetic agents have taken affect, the mouse is placed on a heating pad (38°C) and the electrodes are attached
- Tail (ground)
- Left cheek (reference)
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Cornea (recording)
- Use one drop of Goniosol to moisten cornea
- The rod test is performed with a short-wavelength Wratten filter (# 47A), using stimulation intensities of 8 lumen sec/ft2, and 0.2 HZ frequency, every 10 seconds.
- Data is saved and graphed
- After the dark-adapted tests are run, inject next mouse and put back into dark box. Turn on a steady light to isolate cone responses in rod tested mouse.
- After 8-10 minutes of light adaptation, cone ERGs are obtained to white strobe flashes presented at 1 Hz, with intensities of 16 lumen sec/ft2, every 1 second for 20 seconds.
- Carefully remove the recording electrodes. Anaesthesia reversal is promoted with a subQ injection of (~0.5ml) sterile saline and mouse recovers on a heating pad until fully conscious.
- Data is saved and graphed
- Open indexing program and index and save rods and cones tests.