(R)-Baclofen

Active enantiomer of (RS)-Baclofen. Selective GABA_B receptor agonist. Decreases ethanol intake in addiction models. Shows anti-cataplexy actions and promotes sleep. Blood-brain barrier permeable.

The GABAB_B receptor agonist (R)–Baclofen is commonly used at concentrations of 1–50 µM. It can be used to target presynaptic GABA_B receptors to inhibit neurotransmitter release. At the Schaffer collateral pathway of the hippocampus, (R)–Baclofen from Hello Bio (applied at 10 µM) led to a reversible reduction in presynaptic glutamate release This was demonstrated as a reduced EPSC amplitude and increase in the amplitude ratio of a 50 ms paired pulse stimulation (see Fig 1 above).

#Protocol 1: Assay evoked EPSCs (used for baclofen)

• Whole cell voltage clamp recordings of CA1 pyramidal neurons from the rat hippocampal brain slice.
• 50 ms paired EPSCs were evoked via stimulating electrode placed in the CA3 region to stimulate the Schaffer collateral pathway delivering two square (150 µs) pulse with a 50 ms interval every 10 sec at an intensity that gave a reliable EPSC.
• Neurons were held at -60 mV (the reversal potential of GABA currents).
• Paired EPSCs were continually stimulated and recorded in response to applications of baclofen until a maximum effect was achieved at which point baclofen was washed out with control solution.
• EPSC amplitudes were taken from the amplitude of the first pulse and paired pulse ratios calculated by dividing the amplitude of pulse 2 by pulse 1 (P2/P1).