RRC ID 46344
Author Schultheis C, Brauner M, Liewald JF, Gottschalk A.
Title Optogenetic analysis of GABAB receptor signaling in Caenorhabditis elegans motor neurons.
Journal J Neurophysiol
Abstract In the nervous system, a perfect balance of excitation and inhibition is required, for example, to enable coordinated locomotion. In Caenorhabditis elegans, cholinergic and GABAergic motor neurons (MNs) effect waves of contralateral muscle contraction and relaxation. Cholinergic MNs innervate muscle as well as GABAergic MNs, projecting to the opposite side of the body, at dyadic synapses. Only a few connections exist from GABAergic to cholinergic MNs, emphasizing that GABA signaling is mainly directed toward muscle. Yet, a GABA(B) receptor comprising GBB-1 and GBB-2 subunits, expressed in cholinergic MNs, was shown to affect locomotion, likely by feedback inhibition of cholinergic MNs in response to spillover GABA. In the present study, we examined whether the GBB-1/2 receptor could also affect short-term plasticity in cholinergic MNs with the use of channelrhodopsin-2-mediated photostimulation of GABAergic and cholinergic neurons. The GBB-1/2 receptor contributes to acute body relaxation, evoked by photoactivation of GABAergic MNs, and to effects of GABA on locomotion behavior. Loss of the plasma membrane GABA transporter SNF-11, as well as acute photoevoked GABA release, affected cholinergic MN function in opposite directions. Prolonged stimulation of GABA MNs had subtle effects on cholinergic MNs, depending on stimulus duration and gbb-2. Thus GBB-1/2 receptors serve mainly for linear feedback inhibition of cholinergic MNs but also evoke minor plastic changes.
Volume 106(2)
Pages 817-27
Published 2011-8-1
DOI 10.1152/jn.00578.2010
PII jn.00578.2010
PMID 21613582
PMC PMC3154801
MeSH Amino Acid Sequence Animals Animals, Genetically Modified Caenorhabditis elegans Caenorhabditis elegans Proteins / physiology* Cells, Cultured Molecular Sequence Data Motor Activity / physiology Motor Neurons / physiology* Photic Stimulation / methods* Receptors, GABA-B / physiology* Signal Transduction / physiology*
IF 2.234
Times Cited 15
C.elegans tm1165 tm1406