Nerve growth factor receptor-containing cholinergic neurons of the basal forebrain project to the thalamic reticular nucleus in the rat.
The origin of nerve growth factor receptor-immunoreactive (NGFr-ir) fibers innervating the thalamic reticular nucleus (Rt) was here investigated in the rat using retrograde tracers in combination with immunocytochemistry. Neurons retrogradely labeled from Rt were scattered ipsilaterally throughout the medial septal nucleus and the other cell groups of the basal forebrain, which contained NGFr-ir cells; 10-20% of these retrogradely labeled neurons were also NGFr-ir. Furthermore, a few retrogradely labeled NGFr-ir cells were detected in the basal forebrain on the contralateral side. Retrograde tracing combined with a double immunocytochemical procedure revealed that all the NGFr-ir neurons labeled from Rt also displayed immunoreactivity for choline acetyltransferase. The present results demonstrate that the NGFr-ir neurons of the basal forebrain which project to Rt are cholinergic. The possible functional implications of these findings are discussed.
Institute of Anatomy and Histology, Medical Faculty, University of Verona, Italy.
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Chen
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Bentivoglio
D000818:Animals; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006735:Horseradish Peroxidase; D008297:Male; D009474:Neurons / Q000378:metabolism* / Q000502:physiology*; D010275:Parasympathetic Nervous System / Q000166:cytology / Q000378:metabolism*; D016548:Prosencephalon / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*; D009435:Synaptic Transmission; D013787:Thalamic Nuclei / Q000502:physiology*; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
D017475:Receptors, Nerve Growth Factor; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; C062844:wheat germ agglutinin-apohorseradish peroxidase conjugate gold complex; D006735:Horseradish Peroxidase; D002795:Choline O-Acetyltransferase