Anatomical interconnections of the pedunculopontine tegmental nucleus and the nucleus prepositus hypoglossi in the cat.
The Pedunculopontine tegmental nucleus (PPT) is a mesopontine structure containing predominantly cholinergic neurons, and physiological data indicate its neurons transfer eye-movement gated ponto-geniculo-occipital (PGO) waves to thalamus during the rapid eye movement phase of sleep. The present study, using anterograde and retrograde tracing of wheat germ agglutinin-conjugated horseradish peroxidase, found that the medullary nucleus Prepositus hypoglossi (PH), whose neurons are known to have eye-movement-related information, projects densely to PPT, and PPT has reciprocal projections to PH. The PH-PPT projection has some topographic organization, with rostral PH to rostral PPT and caudal PH to caudal PPT projections dominating. The PH-PPT projection may furnish the anatomical substrate for input of eye movement-related information into the rostral PGO wave system.
Higo
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Department of Psychiatry, Harvard Medical School, Brockton, MA 02401.
Ito
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Fuchs
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McCarley
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RW
D000818:Animals; D001933:Brain Stem / Q000033:anatomy & histology*; D002415:Cats; D006735:Horseradish Peroxidase; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology; D012895:Sleep, REM / Q000502:physiology*; D013681:Tegmentum Mesencephali / Q000033:anatomy & histology*; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D006735:Horseradish Peroxidase