Modulation of lamprey fictive swimming and motoneuron physiology by dopamine, and its immunocytochemical localization in the spinal cord.
The distribution of dopamine immunoreactivity (DA-IR) in lamprey spinal cord was examined using antibodies to dopamine. This revealed a population of small cells slightly ventral to the central canal, with processes extending to it. Ventral to the cells is a sparse plexus of DA-IR fibers. Bath application of DA during glutamate-induced fictive swimming caused cycle rate acceleration at 0.1-1 microM, but slowed the rhythm at higher concentrations (10 microM-1 mM). Bath application or pressure ejection of DA onto spinal motoneurons reduced the late afterhyperpolarization phase of action potentials by 40-50%, without affecting input resistance, membrane potential, or action potential amplitude or duration.
McPherson
D R
DR
Department of Biology, Marquette University, Milwaukee, WI 53233.
Kemnitz
C P
CP
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D004298:Dopamine / Q000502:physiology*; D005110:Extracellular Space / Q000502:physiology; D007150:Immunohistochemistry; D007798:Lampreys / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D013045:Species Specificity; D013116:Spinal Cord / Q000166:cytology / Q000502:physiology*; D013550:Swimming
D004298:Dopamine