Table 1.

Levels of Glial Cell-Derived Neurotrophic Factor in Caudate–Putamen and Substantia Nigra after Infusion of AAV2-GDNF^a

	PUT	CN	GPi	GPe	STN	THAL	SNc	SNr	VTA
LD PUT	++	++	X	X	+++	X	+	+	X
SN	++	++	+++	+++	+++	+++	+++	++	+++
HD PUT	+++	+++	+++	+++	++	++	++	+	X

Abbreviations: CN, caudate nucleus; Gpe, globus pallidus, external segment; GPi, globus pallidus, internal segment; HD PUT, high-dose putamen; LD PUT, low-dose putamen; PUT, putamen; SN, substantia nigra; SNc, substantia nigra pars compacta; SNr, substantia nigra pars reticulata; STN, subthalamic nucleus; THAL, thalamus; VTA, ventral tegmental area.

^aRatings of immunohistochemical visualization of GDNF are indicated as follows: X, absence of immunoreactivity (IR); +, <25% coverage of structure with a few scattered IR neurons or fibers, and pale staining intensity; ++, >25% to <50% coverage of structure; +++, >50% coverage of structure, GDNF-positive cells and fibers and extracellular IR, intense staining.