PT  - JOURNAL ARTICLE
AU  - Hanson, G R
AU  - Alphs, L
AU  - Wolf, W
AU  - Levine, R
AU  - Lovenberg, W
TI  - Haloperidol-induced reduction of nigral substance P-like immunoreactivity: a probe for the interactions between dopamine and substance P neuronal systems.
DP  - 1981 Aug 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 568--574
VI  - 218
IP  - 2
4099  - http://jpet.aspetjournals.org/content/218/2/568.short
4100  - http://jpet.aspetjournals.org/content/218/2/568.full
SO  - J Pharmacol Exp Ther1981 Aug 01; 218
AB  - Protracted blockade of dopamine receptors by haloperidol has been shown to cause a reduction in nigral content of substance P-like immunoreactivity (SPLI). This pharmacological effect is used to study the mechanisms whereby the dopaminergic and substance P systems interact. Data presented in this paper suggest that 1) blockade of dopamine postsynaptic receptors alters nigral SPLI levels associated with the substance P striatal-nigral loop, 2) destruction of the nigral-striatal dopaminergic pathway results in changes in nigral content of SPLI similar to that induced by haloperidol, 3) several weeks after nigral-striatal lesions, compensatory mechanisms mediate a return of nigral SPLI content to control levels and 4) substance P striatal-nigral circuits continue to respond to dopaminergic input after kainic acid lesions in the anterior striatum, whereas properly placed mechanical striatal-nigral lesions appear to be effective in preventing this interaction. The data support a dynamic role for striatal-nigral substance P fibers in the extrapyramidal circuitry and suggest that his pathway must be accounted for when studying the interactions of transmitter systems within this locomotor center.