Neurokinin A and substance P in striato-nigral neurons in rat brain.

The effect of an ibotenic acid lesion in rostral striatum on tissue levels of neurokinin A and substance P in striatum and substantia nigra was studied in rat brain. A total of 32 micrograms (10 mg/ml) ibotenic acid was injected in four positions to lesion striatal cell bodies rostral to bregma. The neurokinin A level was reduced to a third of the control value in striatum and to less than half of the control level in substantia nigra. Neurokinin A, in addition to substance P, is shown to be possibly present in striato-nigral neurons, which provides further evidence for the existence of a striato-nigral tachykinin pathway.