Immunocytochemical localization of TASK-3 channels in rat motor neurons.
Motor neurons are large cholinergic neurons located in the brain stem and spinal cord. In recent years, a functional role for TASK channels in cellular excitability and vulnerability to anesthetics of motor neurons has been described. Using a polyclonal monospecific antibody against the tandem pore domain K(+) channel (K2P channel) TWIK-related acid-sensitive K(+) channel (TASK-3), we analyzed the expression of the TASK-3 protein in motor systems of the rat CNS. Immunocytochemical staining showed strong TASK-3 expression in motor neurons of the facial, trigeminal, ambiguus, and hypoglossal nuclei. Oculomotor nuclei (including trochlear and abducens nucleus) were also strongly positive for TASK-3. The parasympathetic Edinger-Westphal nucleus and dorsal vagal nucleus showed significant, but weaker expression compared with somato- and branchiomotoric neurons. In addition, motor neurons in the anterior horn of the spinal cord were also strongly labeled for TASK-3 immunoreactivity. Based on morphological criteria, TASK-3 was found in the somatodendritic compartment of motor neurons. Cellular staining using methyl green and immunofluorescence double-labeling with anti-vesicular acetylcholine transporter (anti-vAChT) indicated ubiquitous TASK-3 expression in motor neurons, whereas in other brain regions TASK-3 showed a widespread but not ubiquitous expression. In situ hybridization using a TASK-3 specific riboprobe verified the expression of TASK-3 in motor neurons at the mRNA level.
Institut für Integrative Neuroanatomie, Charité, Philippstr. 12, 10115 Berlin, Germany.
Christiane
C
Marinc
Harald
H
Prüss
Christian
C
Derst
Rüdiger W
RW
Veh
D000818:Animals; D007150:Immunohistochemistry; D008297:Male; D009046:Motor Neurons / Q000166:cytology / Q000378:metabolism*; D024683:Potassium Channels, Tandem Pore Domain / Q000378:metabolism*; D021381:Protein Transport; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism
C407082:Kcnk9 protein, rat; D024683:Potassium Channels, Tandem Pore Domain