[Peptidergic asymmetry of the rat spinal cord].

Intracisternal administration of extractant-1M 90 degrees C acetic acid within 15 min into intact rats neutralizes the left and the right half of the lumbar part of the rat spine thus prolonging passive extension, while dorsal application causes the muscle tension of the back extremity. The effects are probably due to the peptidergic asymmetry of the rat spine.