(-)-Bicuculline methiodide

Technical documents: SDS CoA Datasheet

Product overview

Name (-)-Bicuculline methiodide
Description Prototypic, competitive GABAA receptor antagonist
Biological description

Methiodide salt form of (+)-bicuculline.

Prototypic, competitive GABAA receptor antagonist which displaces GABA from the agonist binding site to prevent receptor activation. 

Also acts as a negative allosteric inhibitor of channel opening to inhibit GABAA receptor activation by anaesthetic agents.

Additionally shows activity at SK calcium-activated potassium channels, nicotinic acetylcholine receptors and acetylcholinesterase.

Reversibly and competitively blocks GABAA receptor mediated currents. Widely used to isolate glutamate receptor mediated EPSCs (excitatory postsynaptic potentials).

Shows convulsant action and induces epilepsy.

Freebase, methochloride and methobromide salts also available.

Alternative names BIC, BMI
Purity >98%
Customer comments

Good quality product: (-)-Bicuculline methiodide is used routinely in our lab for a number of experiments. It is shipped quickly, packaged well, dissolves without problem, and blocks GABAA-receptor activity as it should! Verified customer, Sickkids foundation

We routinely use this compound from Hello Bio to inhibit GABA-A receptors in electrophysiological recordings from rodent brain slices. Verified customer, University of Montana

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Biological Data

Application notes

The GABAA receptor antagonist bicuculline is commonly used to reduce levels of inhibition by blocking the actions of the neurotransmitter GABA. Bicuculline is commonly used at concentrations of 100 μM and above.

Bicuculline methiodide from Hello Bio reduces both spontaneous inhibitory post synaptic currents (IPSC) and evoked IPSCs (see Fig 1 above). It was effective at concentrations of 1 mM with complete receptor blockade at 100 μM.


#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 Bicuculline methiodide until complete receptor inhibition.
  • Spontaneous IPSCs were recorded before and after addition of Bicuculline methiodide by holding the neuron at 0mV and recording for 10 sec.
  • All recordings for IPSCs were made in the presence of AMPAR antagonists.

Solubility & Handling

Storage instructions Room temperature
Solubility overview Soluble in water (20mM) or DMSO (50mM)
Handling This compound is light sensitive; exposure to light may affect compound performance. We therefore recommend storing the solid material and any solutions in the dark and protecting from light.
Important This product is for RESEARCH USE ONLY and is not intended for therapeutic or diagnostic use. Not for human or veterinary use.



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Chemical Data

Chemical name [R-(R*,S*)]-5-(6,8-Dihydro-8-oxofuro[3,4-e]-1,3-benzodioxol-6-yl)-5,6,7,8-tetrahydro-6,6-dimethyl-1,3-dioxolo[4,5-g]isoquinolinium iodide
Molecular Weight 509.3
Chemical structure Product image
Molecular Formula C21H20INO6
CAS Number 40709-69-1
PubChem identifier 104871
SMILES C[N+]1(CCC2=CC3=C(C=C2C1C4C5=C(C6=C(C=C5)OCO6)C(=O)O4)OCO3)C.[I-]
Source Synthetic
InChi InChI=1S/C21H20NO6.HI/c1-22(2)6-5-11-7-15-16(26-9-25-15)8-13(11)18(22)19-12-3-4-14-20(27-10-24-14)17(12)21(23)28-19;/h3-4,7-8,18-19H,5-6,9-10H2,1-2H3;1H/q+1;/p-1/t18-,19+;/m0./s1
MDL number MFCD00078966
Appearance Yellow solid

References for (-)-Bicuculline methiodide

References are publications that support the biological activity of the product
  • Advantages of an antagonist: bicuculline and other GABA antagonists.

    Johnston GA (2013) Br J Pharmacol 169(2) : 328-36.
  • Differential effects of iontophoretic in vivo application of the GABA(A)-antagonists bicuculline and gabazine in sensory cortex.

    Kurt S et al (2006) Hear Res 212(1-2) : 224-35.
  • [Bicuculline inhibits airway remodeling in a murine model of chronic asthma].

    Zhu T et al (2010) Nan Fang Yi Ke Da Xue Xue Bao 30(4) : 842-6.
These publications cite the use of (-)-Bicuculline methiodide purchased from Hello Bio:
  • Artifactual hyperpolarization during extracellular electrical stimulation: Proposed mechanism of high-rate neuromodulation

    Lesperance et al (2017) Brain stimulation xxx : 1-10
  • Activation of TRPC1 Channel by Metabotropic Glutamate Receptor mGluR5 Modulates Synaptic Plasticity and Spatial Working Memory

    Lepennetier et al (2018) Front. Cell. Neurosci. https://doi.org/ : 10.3389/fncel.2018.00318
  • Activation of Serotonin 5-HT7 Receptors Modulates Hippocampal Synaptic Plasticity by Stimulation of Adenylate Cyclases and Rescues Learning and Behavior in a Mouse Model of Fragile X Syndrome.

    Costa et al (2018) Front Mol Neurosci. 11:353 : doi: 10.3389/fnmol.2018.00353
    PubMedID: 30333723
  • Acute Complexin Knockout Abates Spontaneous and Evoked Transmitter Release.

    López-Murcia (2521-2530) Cell Rep. : 26(1)
    PubMedID: 30840877
  • Photopotentiation of the GABA<sub>A</sub> receptor with caged diazepam

    Sansalone L et al (2019) Proc Natl Acad Sci U S A 116(42) : 21176-21184
    PubMedID: 31575739

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