RETROGRADE TRANSPORT OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) FOLLOWING INFUSION IN NEO-CORTEX AND LIMBIC CORTEX IN RAT - RELATIONSHIP TO BDNF MESSENGER-RNA EXPRESSING NEURONS

Brain-derived neurotrophic factor (BDNF) was the second member of the nerve growth factor (NGF) family to be isolated. The ability of BDNF t o be retrogradely transported following intraparenchymal infusion repr esents a unique neurobiological tool to determine the location of puta tive neuron-specific BDNF-responsive neuronal systems. In the present study, we infused recombinant human (rh) BDNF into the rodent neo- and limbic cortex and used a turkey anti-BDNF antibody to determine speci fic populations of neurons which retrogradely transport this neurotrop hin. Frontal cortex infusion retrogradely labeled neurons within the i psilateral and contralateral frontal cortex, basal forebrain, lateral hypothalamus, centrolateral, mediodorsal, ventrolateral, ventromedial, ventral posterior, rhomboid, reuniens, and medial geniculate thalamic nuclei, and locus coeruleus. Occipital cortex infusion retrogradely l abeled neurons in the frontal, temporal, occipital, and perirhinal cor tices as well as the claustrum, basal forebrain, thalamus, epithalamus , hypothalamus, and raphe nuclei. Dorsal hippocampal infusion retrogra dely labeled neurons within the septal diagonal band, supramammillary nucleus, and entorhinal cortex and was also transported within various hippocampal subfields. Entorhinal cortex infusion retrogradely labele d neurons within the perirhinal cortex, endopiriform nucleus, piriform cortex, dentate gyrus, presubiculum, parasubiculum, CA1-CA4 fields, a mygdaloid nuclei, basal forebrain, thalamus, hypothalamus, periaqueduc tal gray, raphe nuclei, and locus coeruleus. Amygdala infusion labeled neurons in the endopiriform nucleus, temporal cortex, piriform cortex , paralimbic cortex, hippocampus, subiculum, entorhinal cortex, amygda la, basal forebrain, thalamus, hypothalamus, substantia nigra, pars co mpacta, raphe, and pontine parabrachial nuclei. In situ hybridization experiments demonstrated that virtually all areas which retrogradely t ransport BDNF also express its message. Neuroanatomical distributional studies of BDNF will unravel specific central nervous system neurotro phic-responsive systems. (C) 1996 Wiley-Liss, Inc.