Secretin facilitates GABA transmission in the cerebellum.
Secretin was the first hormone discovered in human history, and yet, its function as a neuropeptide has been overlooked in the past. The recent discovery of the potential use of secretin in treating autistic patients, together with the conflicting reports on its effectiveness, urges an in-depth investigation of this issue. We show here that in the rat cerebellar cortex, mRNAs encoding secretin are localized in the Purkinje cells, whereas those of its receptor are found in both Purkinje cells and GABAergic interneurons. Immunoreactivity for secretin is localized in the soma and dendrites of Purkinje cells. In addition, secretin facilitates evoked, spontaneous, and miniature IPSCs recorded from Purkinje cells. We propose that secretin is released from the somatodendritic region of Purkinje cells and serves as a retrograde messenger modulating GABAergic afferent activity.
Yung
W H
WH
Department of Physiology, The Chinese University of Hong Kong, Shatin, Hong Kong.
Leung
P S
PS
Ng
S S
SS
Zhang
J
J
Chan
S C
SC
Chow
B K
BK
D000262:Adenylyl Cyclases / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D003712:Dendrites / Q000378:metabolism; D020536:Enzyme Activators / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017403:In Situ Hybridization; D007395:Interneurons / Q000187:drug effects / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D010320:Parvalbumins / Q000096:biosynthesis / Q000235:genetics; D018408:Patch-Clamp Techniques; D011689:Purkinje Cells / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled; D011964:Receptors, Gastrointestinal Hormone / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012633:Secretin / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D020536:Enzyme Activators; D004791:Enzyme Inhibitors; D010320:Parvalbumins; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D011964:Receptors, Gastrointestinal Hormone; C029937:secretin receptor; D012633:Secretin; D005680:gamma-Aminobutyric Acid; D000262:Adenylyl Cyclases