δ subunit-containing GABA_A IPSCs are driven by both synaptic and diffusional GABA in mouse dentate granule neurons.

ABSTRACT:

Key points

Current views suggest γ2 subunit-containing GABA_A receptors mediate phasic IPSCs while extrasynaptic δ subunits mediate diffusional IPSCs and tonic current. We have re-examined the roles of the two receptor populations using mice with picrotoxin resistance engineered into receptors containing the δ subunit. Using pharmacological separation, we find that in general δ and γ IPSCs are modulated in parallel by manipulations of transmitter output and diffusion, with evidence favouring modestly more diffusional contribution to δ IPSCs. Our findings also reveal that spontaneous δ IPSCs are mainly driven by channel deactivation, rather than by diffusion of GABA. Understanding the functional contributions of the two receptor classes may help us understand the actions o

SUBMITTER: Sun MY 

PROVIDER: S-EPMC7071981 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature