Related Experiment Video
Updated: Oct 26, 2026

GABA-activated Single-channel and Tonic Currents in Rat Brain Slices
Published on: July 17, 2011
Pharmacological modulation of GABA(A) receptor-mediated postsynaptic potentials in the CA1 region of the rat
1Department of Pharmacology, University of Edinburgh.
Abstract:
It is unclear whether GABA(A) receptor-mediated hyperpolarizing and depolarizing synaptic potentials (IPSP(A)s and DPSP(A)s, respectively) are evoked by (a) the same populations of GABAergic interneurones and (b) exhibit similar regulation by allosteric modulators of GABA(A) receptor function. We have attempted to address these questions by investigating the effects of (a) known agonists for presynaptic receptors on GABAergic terminals, and (b) a range of GABA(A) receptor ligands, on each response. The GABA uptake inhibitor NNC 05-711 (10 microM) enhanced whereas bicuculline (10 microM) inhibited both IPSP(A)s and DPSP(A)s. (-)-Baclofen (5 microM), [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin (DAGO; 0.5 microM), and carbachol (10 microM) caused substantial depressions (up to 99%) of DPSP(A)s that were reversed by CGP 55845A (1 microM), naloxone (10 microM) and atropine (5 microM), respectively. In contrast, 2-chloroadenosine (CADO; 10 microM) only slightly depressed DPSP(A)s. Quantitatively, the effect of each agonist was similar to that reported for IPSP(A)s. The neurosteroid ORG 21465 (1 - 10 microM), the anaesthetic propofol (50-500 microM), the barbiturate pentobarbitone (100-300 microM) and zinc (50 microM) all enhanced DPSP(A)s and IPSP(A)s. The benzodiazepine (BZ) agonist flunitrazepam (10-50 microM) and inverse agonist DMCM (1 microM) caused a respective enhancement and inhibition of both IPSP(A)s and DPSP(A)s. The BZomega1 site agonist zolpidem (10-30 microM) produced similar effects to flunitrazepam. The anticonvulsant loreclezole (1-100 microM) did not affect either response. These data demonstrate that similar populations of inhibitory interneurones can generate both IPSP(A)s and DPSP(A)s by activating GABA(A) receptors that are subject to similar allosteric modulation.
More Related Videos
07:16Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission
Published on: August 16, 2018
07:51Inhibitory Synapse Formation in a Co-culture Model Incorporating GABAergic Medium Spiny Neurons and HEK293 Cells Stably Expressing GABAA Receptors
Published on: November 14, 2014
Related Concept Videos
Antiepileptic Drugs: GABAergic Pathway Potentiators
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for their...
Ligand-Gated Ion Channel Receptor: Gating Mechanism
G-Protein Gated Ion Channels
Sensory organs,...