Evidence for substance P in the striato-nigral tract.
The highest concentration of substnace P yet found in the mammalian brain is in the reticular part of the substantia nigra. The effect of various lesions on the substance P content of that region has been examined in the rat in order to determine the possible sources and paths of nigropetal substance P-containing fibers. Unilateral knife cuts which transect the medial forebrain bundle and medial portion of the crus cerebri at a premammillary level lead to a 90% reduction in substance P in the ipsilateral reticular part of substantia nigra, with no significant effect on contralateral values. Incomplete electrolytic lesions of the globus pallidus lead to a 50% decrease. These data indicate that descending uncrossed pathways provide most of the substance P in the reticular part of the substantia nigra, with the striato-nigral tract providing an important component.
D000344:Afferent Pathways / Q000502:physiology*; D000818:Animals; D003342:Corpus Striatum / Q000502:physiology*; D005260:Female; D005917:Globus Pallidus / Q000502:physiology; D007034:Hypothalamus, Posterior / Q000502:physiology; D051381:Rats; D013373:Substance P / Q000378:metabolism*; D013378:Substantia Nigra / Q000378:metabolism*
D013373:Substance P