Picrotoxin

The GABA_A receptor antagonist Picrotoxin is commonly used to reduce the levels inhibition by blocking the actions of the neurotransmitter GABA. Picrotoxin from Hello Bio reduces both spontaneous inhibitory post synaptic currents (IPSC) and evoked IPSCs. It was effective at concentrations of 10μM, with complete receptor blockade at 100μM. For assay protocol, see #Protocol 1 in Application Notes below

#Protocol 1: Evoked and spontaneous inhibitory post synaptic currents (IPSCs)

• Whole cell voltage clamp recordings were obtained from layer V neurons of the mouse prelimbic cortex brain slice.
• A stimulating electrode was placed in layers II/III and IPSCs were evoked by a single square (150 μs) pulse every 10 sec at a stimulus intensity that gave a reliable IPSC.
• IPSCs were evoked at a range of neuron holding voltages to measure the reversal potential of the current to ensure it was GABAergic.
• Neurons were held at 0mV and IPSCs continuously stimulated and recorded in response to 5 min applications of varying concentrations of Gabazine until complete receptor inhibition.
• Spontaneous IPSCs were recorded before and after addition of Gabazine by holding the neuron at 0mV and recording for 10 sec.
• All recordings for IPSCs were made in the presence of AMPAR antagonists.