Distribution of Brain-Derived Neurotrophic Factor-Immunoreactive Neurons and Axon Terminals in the Rat Brain

Lee, Sung Won; Kim, Jeong Ki; Kim, Dong Sun; Cho, Hee Jung

Abstract

Because of its broad range of activities, BDNF is being tested or considered for treatment of a variety of neurodegen-erative diseases. However, a discrepancy exists in the literature concerning the localization of BDNF-immunoreactive (IR) structures in the brain. We performed, therefore, immunohistochemistry to investigate the regional distribution of BDNF-IR neurons and axon terminals in the rat brain. The results obtained were as follows; Telencephalon : BDNF-IR neurons were found in the anterior olfactory nucleus (n.), the piriform cortex, the neocortex, the lateral septum, the claustrum, the pyramidal layer of CA2 and CA3, the basolateral amygdaloid n. and the bed n. of the stria terminalis. BDNF-IR axon terminals were localized in the lateral septum, the stratum lucidum of CA2 and CA3, the hilum, the dentate gyrus, the central amygdaloid n. and the bed n. of the stria terminalis. Diencephalon : BDNF-IR neurons were demonstrated in the medial geniculate n., the mammillary n. and the ventromedial hypothalamic n. In the anteromedial thalamic n., the anteroventral thalamic n., the paraventricular thalamic n., the lateral geniculate n. and the medial habenular n., densely stained IR terminals were found. Midbrain : BDNF-IR terminals were localized in the substantia nigra, the ventral tegmental area and the periaqueductal gray. Pons : Densely stained IR terminals were found in the ventral tegmental n. and the parabranchial n.. BDNF-IR neurons were localized in the inferior colliculus, the pontine n. and the motor trigeminal n. Medulla oblongata : BDNF-IR neurons were found in the inferior olive n. and the area postrema. IR terminals were localized in the inferior olive n., the lateral reticular n., the dorsal cap of Kooy, the n. tractus solitarious and the spinal trigeminal n. The results show that BDNF-IR neurons and terminals are distributed in numerous structures of the brain and that BDNF may be related with a various function of the regions.