Effects of the synthetic cannabinoid 5F-AMB on anxiety and recognition memory in mice.
Shiho Ito, Satoshi Deyama, Masaki Domoto, Tong Zhang, Hitoki Sasase, Akari Fukao, Hirohito Esaki, Eiichi Hinoi, Shuji Kaneko, Katsuyuki Kaneda
Psychopharmacology July 1, 2019 DOI: 10.1007/s00213-019-05222-2 via PubMed
Summary
AI-generated from the abstractThe synthetic cannabinoid 5F-AMB, when injected into the brain of mice, reduces anxiety and impairs the acquisition of recognition memory by activating CB1 receptors. Systemic injection severely reduces movement, an effect partially blocked by a CB1 antagonist. Infusion into the medial prefrontal cortex impairs memory acquisition but does not affect anxiety, suggesting other brain regions mediate the anxiolytic effect.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | C57BL/6J mice |
| Interventions | 5F-AMB AM251 |
| Dose | 0.3 mg/kg (intraperitoneal), 10 nmol (intracerebroventricular), 10 pmol/side (intra-mPFC); AM251 3 mg/kg (intraperitoneal), 1.8 nmol (co-infusion) |
| Keywords | 5f-amb Designer drug Medial prefrontal cortex Synthetic cannabinoids |
| Key finding | Centrally administered 5F-AMB produces anxiolytic effects and impairs recognition memory acquisition via CB1 receptor activation, while systemic administration severely impairs locomotor activity. |
Abstract
N-[[1-(5-fluoropentyl)-1H-indazol-3-yl]carbonyl]-L-valine methyl ester (5F-AMB) is a synthetic cannabinoid that has been distributed recently. Although inhalation of 5F-AMB produces adverse effects, such as impaired memory and disturbed consciousness, in humans, the psychopharmacological effects of 5F-AMB in rodents have not been investigated. We first examined the effects of intraperitoneal and intracerebroventricular injections of 5F-AMB on anxiety-like behavior and locomotor activity in the open field (OF) test and recognition memory in the novel object recognition test (NOR) in C57BL/6J mice. We also examined whether a cannabinoid 1 (CB1) receptor antagonist AM251 blocks the effects of 5F-AMB. We next examined the effects of 5F-AMB infusion into the medial prefrontal cortex (mPFC), a brain region associated with anxiety and memory, on these tests. Intraperitoneal injection of 5F-AMB (0.3 mg/kg) dramatically decreased locomotor activity in the OF, and this effect was partially reversed by AM251 (3 mg/kg). Intracerebroventricular infusion of 5F-AMB (10 nmol) produced an anxiolytic effect in the OF and impaired acquisition, but not retrieval, of recognition memory in the NOR, and these effects were blocked by co-infusion of AM251 (1.8 nmol). Bilateral intra-mPFC infusion of 5F-AMB (10 pmol/side) similarly produced impaired recognition memory acquisition, but no anxiolytic effect. The results demonstrate that centrally administered 5F-AMB produces anxiolytic effect and impaired recognition memory acquisition via activation of CB1 receptors, while systemic 5F-AMB severely impaired locomotor activity. The mPFC is involved in 5F-AMB-induced impairment of recognition memory acquisition. However, other brain region(s) may contribute to the 5F-AMB-induced anxiolytic effect.