title: Structure and function of barrel 'precursor' cells in trigeminal nucleus principalis.
abstract: Intracellular recording, electrical stimulation, receptive field mapping, HRP injection, and computer reconstruction techniques were used to study principalis cells in rat. They (n = 80) responded within 1.2 +/- 0.2 ms of trigeminal ganglion shocks and 69% were antidromically activated by thalamic shocks; 69% were vibrissa-sensitive, of which 80% responded to only a single vibrissa. The remainder responded only to guard hairs, skin, teeth, or nociceptors. Stained thalamic-projecting cells with one vibrissa receptive fields had stereotyped morphologies. Small somata gave rise to dendrites which extended only a short distance from the soma, where they branched extensively. Each tree was polarized, spanning no more than a hemisphere around the soma; however, there was no consistent direction of polarity. Dendritic trees extended 68 +/- 14, 95 +/- 48, and 91 +/- 29 micron in the transverse, sagittal and horizontal planes, respectively. Dendritic spines were rare, yet swellings were common. Axons never branched locally.
authors.affiliation: Department of Anatomy and Neurobiology, St. Louis University School of Medicine, MO 63104.
authors.forename: M F
authors.initials: MF
authors.lastname: Jacquin
authors.forename: J
authors.initials: J
authors.lastname: Golden
authors.forename: W M
authors.initials: WM
authors.lastname: Panneton
mesh_terms: D000200:Action Potentials; D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D001933:Brain Stem / Q000166:cytology / Q000502:physiology*; D003712:Dendrites / Q000502:physiology / Q000648:ultrastructure; D004558:Electric Stimulation; D005260:Female; D006735:Horseradish Peroxidase; D007091:Image Processing, Computer-Assisted; D008297:Male; D009475:Neurons, Afferent / Q000502:physiology* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D013788:Thalamus / Q000502:physiology; D014276:Trigeminal Nerve / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D006735:Horseradish Peroxidase