**Background**
The $\text{GABA}_{\text{B}}$ receptor is a G protein-coupled receptor that plays a critical role in modulating neurotransmission throughout the central nervous system. Unlike $\text{GABA}_{\text{A}}$ receptors, which mediate fast inhibitory synaptic transmission, $\text{GABA}_{\text{B}}$ receptors mediate slow, prolonged inhibitory postsynaptic potentials and regulate the release of other neurotransmitters. Dysregulation of $\text{GABA}_{\text{B}}$ signaling is implicated in various neurological disorders, including cognitive impairments and developmental deficiencies. Consequently, the development of selective antagonists is essential for understanding the physiological role of these receptors and exploring potential therapeutic interventions for brain dysfunction. In this context, we will introduce a potent $\text{GABA}_{\text{B}}$ receptor antagonist – CGP55845.
**Definition**
CGP55845 hydrochloride is a potent and selective $\text{GABA}_{\text{B}}$ receptor antagonist with an $\text{IC}_{50}$ value of 6 nM.
**In Vitro and In Vivo Studies**
The CGP55845 description highlights its utility in studying synaptic plasticity and cognitive recovery. Regarding CGP55845 in vitro activity, studies conducted in the mouse visual cortex demonstrated that CGP55845 hydrochloride (1 $\mu$M) increases the frequency of spontaneous $\text{Ca}^{2+}$ transients as well as spontaneous and miniature inhibitory postsynaptic currents (mIPSCs). Notably, it does not affect the amplitudes or kinetics of mIPSCs. Furthermore, the compound significantly increases evoked IPSC (eIPSC) amplitudes and decreases the paired-pulse ratio (PPR).
In terms of CGP55845 In Vivo application, the compound has shown significant efficacy in mouse models of CDKL5 deficiency disorder. In 2-month-old male $\text{Cdkl5}^{+/Y}$ and $\text{Cdkl5}^{-/Y}$ mice, a single intraperitoneal (i.p.) administration of CGP55845 hydrochloride at a dose of 0.5 mg/kg increased the number of PSD95 positive puncta. It also enhanced the density and maturation of dendritic spines in the perirhinal cortex (PRC). Most importantly, this treatment restored novel object recognition (NOR) memory in $\text{Cdkl5}^{-/Y}$ mice. For researchers seeking specific CGP55845 technical information, these results suggest that blocking $\text{GABA}_{\text{B}}$ receptors can rescue both functional and structural impairments in the perirhinal cortex. In conclusion, CGP55845 is a highly selective $\text{GABA}_{\text{B}}$ receptor antagonist that serves as a valuable tool for neurological research.
Keywords
CGP55845, 149184-22-5, CGP 55845, CGP-55845, GABA Receptor, Gamma-aminobutyric acid Receptor, γ-Aminobutyric acid Receptor, GABAB, neurological, Baclofen, Inhibitor, inhibitor, inhibit
References
[1] Laura Gennaccaro, et al. A GABA B receptor antagonist rescues functional and structural impairments in the perirhinal cortex of a mouse model of CDKL5 deficiency disorder. Neurobiol Dis. 2021 Jun;153:105304.
[2] Claire-Marie Vacher, et al. GABA(B) receptors as potential therapeutic targets. Curr Drug Targets CNS Neurol Disord. 2003 Aug;2(4):248-59.
[3] Knut Kirmse, et al. Ambient GABA constrains the strength of GABAergic synapses at Cajal-Retzius cells in the developing visual cortex. J Neurosci. 2006 Apr 19;26(16):4216-27.