Control of lamprey locomotor neurons by colocalized monoamine transmitters
- 1 March 1995
- journal article
- Published by Springer Nature in Nature
- Vol. 374 (6519) , 266-268
- https://doi.org/10.1038/374266a0
Abstract
Neurons in the central nervous system (CNS) often store more than one neurotransmitter, but as yet the functional significance of this type of coexistence is poorly understood. 5-Hydroxytryptamine (5-HT) modulates calcium-dependent K+ channels (KCa) responsible for the postspike afterhyperpolarization in different regions of the CNS. In lamprey, 5-HT neurons control apamine-sensitive KCa channels in spinal locomotor network interneurons, thereby in addition regulating the duration of locomotor bursts. We report here that these spinal 5-HT neurons also contain dopamine. Like 5-HT, dopamine causes a reduction of the afterhyperpolarization, but in this case it is due to a reduction of calcium entry during the action potential, which results in a reduced activation of KCa. 5-HT and dopamine are both released from these midline neurons, and both reduce the afterhyperpolarization through two distinctly different, but complementary cellular mechanisms. The net effect of dopamine (10-100 microM) on the locomotor network is similar to that of 5-HT, and the effects of dopamine and 5-HT are additive at the network level.Keywords
This publication has 19 references indexed in Scilit:
- Effects of serotonin on fictive locomotion coordinated by a neural network deprived of NMDA receptor-mediated cellular propertiesExperimental Brain Research, 1993
- Local serotonergic modulation of calcium-dependent potassium channels controls intersegmental coordination in the lamprey spinal cordJournal of Neurophysiology, 1992
- Calcium-dependent potassium currents in neurons from cat sensorimotor cortexJournal of Neurophysiology, 1992
- Three types of GABA-immunoreactive cells in the lamprey spinal cordBrain Research, 1990
- Increase in endogenous 5-hydroxytryptamine levels modulates the central network underlying locomotion in the lamprey spinal cordNeuroscience Letters, 1989
- A spinal projection of 5-hydroxytryptamine neurons in the lamprey brainstem; evidence from combined retrograde tracing and immunohistochemistryNeuroscience Letters, 1986
- Ionic mechanisms of 3 types of functionally different neurons in the lamprey spinal cordBrain Research, 1985
- Immunohistochemical demonstration of some putative neurotransmitters in the lamprey spinal cord and spinal ganglia: 5‐hydroxytryptamine‐, tachykinin‐, and neuropeptide‐Y‐immunoreactive neurons and fibersJournal of Comparative Neurology, 1985
- Distribution of serotonergic neurons and processes in the lamprey spinal cordNeuroscience, 1985
- Cerebrospinal fluid-contacting neurons of the central canal and terminal ventricle in various vertebratesCell and tissue research, 1983