CHRONIC MORPHINE EXPOSURE AFFECTS VISUAL RESPONSE LATENCY OF THE LATERAL GENICULATE NUCLEUS IN CATS

SUMMARY 1 Chronic morphine exposure results in degradation of the functional properties of cortical cells. However, little evidence has been reported about the effect of morphine on the temporal properties of the visual system. 2 We compared the visual response latency of different cells of the lateral geniculate nucleus (LGN) in morphine (10 mg/mL)- and saline-treated cats. Morphine-treated cats were given morphine sulphate by cervical subcutaneous injection twice daily for 10 days, whereas saline-treated cats received injections of 0.9% saline instead. We found that LGN neurons in morphine-treated cats exhibited significantly longer response latency than those in saline-treated cats (P