Table 1.

Summary of expression of GDNF, GDNFR-α, and RET mRNA

Brain structure	GDNF	GDNFR-α	RET
Olfactory system
Olfactory tubercule	++	+	−
Internal granular layer of olfactory bulb	+	+	+
External plexiform layer of olfactory bulb	−	+	−
Glomerular layer	−	±	++
Olfactory nerve layer	−	+	+
Cingulate cortex	+	+	−
Neocortex	±	++	−
Hippocampus	+	++	(+)
Amygdala	−	++	±
Caudate-putamen	+	−	−
Accumbens	+	−	−
Lateral septal nucleus	−	+++	−
Septum medialis	−	±	++
Hypothalamic nuclei	−	++	+
Thalamus
Reticular thalamic nucleus	−	+++	++
Zona incerta	−	+++	+
Subthalamic nucleus	−	−	++
Ventroposterolateral/medial nucleus	+	−	−
Anteromedial and dorsal thal nucl	+	+	−
Anteroventral thalamic nucleus	++	−	−
Ventromedial thalamic nucleus	+	−	−
Lateral habenular nucleus	−	+++	++
Medial habenular nucleus	−	+++	++
Mesencephalon
Substantia nigra compacta and scattered  cells of SN reticulata	−	+++	+++
Ventral tegmental area	−	+++	+++
Interpeduncular nucleus	−	+++	+++
Supramammilary nucleus	−	++	+++
Red nucleus	−	++	+++
Dorsal raphe nucleus	−	++	++
Cerebellum
Granular layer (not granule cells)	+	−	+
Purkinje layer (not Purkinje cells)	(+)	++	++
Molecular layer	−	++	++
Deep cerebellar nuclei	(+)	+	++
Pons
Pontine reticular nucleus	−	++	+
Pontine nucleus	−	±	++
Motor trigeminal nucleus	−	+++	+++
Inferior olive nuclei	−	+	++
Locus coeruleus	−	+	+
Dorsal cochlear nucleus	−	+++	+
Facial nucleus	−	+++	+++
Vestibular nucleus	−	+	+
Hypoglossal nucleus	−	+++	+

Semiquantitative analysis depicted as high levels, +++; moderate, ++; low, +; marginally detectable, (+); scattered populations at generally very low levels, ±.