Electrophysiological Measurement of Cannabinoid‐Mediated Synaptic Modulation in Acute Mouse Brain Slices

Abstract

Endocannabinoids (eCBs) are a class of bioactive lipids that mediate retrograde synaptic modulation at central and peripheral synapses. The highly lipophilic nature of eCBs and the pharmacological tools available to interrogate this system require unique methodological consideration, especially when applied to ex vivo systems such as electrophysiological analysis in acute brain slices. Here we discuss protocols for measuring cannabinoid and eCB-mediated synaptic signaling in mouse brain slices including analysis of short-term, long-term, and tonic eCB signaling modes, and the unique considerations for working with eCBs and TRPV1/cannabinoid ligands in acute brain slices.

Endocannabinoids regulate cocaine-associated memory through brain AEA–CB1R signalling activation

“…As retrograde signals, eCBs are released in both tonic and activity-dependent phasic modes [ [30] , [31] , [32] ]. 2-AG is a high-affinity agonist of CB1Rs, while AEA is a low-affinity agonist [ 11 ].…”

2-AG-Mediated Control of GABAergic Signaling Is Impaired in a Model of Epilepsy

“…For example, extracellular Ca 2+ concentration used in the recording solution might alter release probability (Mintz et al, 1995), synaptic plasticity (Inglebert et al, 2020), and eCB signaling (Lenz and Alger, 1999;Varma et al, 2002). The extracellular solution in these experiments (2.5 mM Ca 2+ and 1.5 mM Mg 2+ ) included concentrations of Ca 2+ in the upper value of physiological levels in rat brain (1-3 mM) (Rusakov and Fine, 2003) as it is widely used to test eCB control of synaptic transmission (Báldi et al, 2016).…”

Patch-clamp and multi-electrode array electrophysiological analysis in acute mouse brain slices

“… Continue to examine changes in EPSC amplitude as BAC-containing ACSF begins to enter the recording chamber ( Figures 4 C–4E). CRITICAL: Given that compounds possess distinct solubility profiles, superfuse, or introduce into the ACSF perfusion medium, drugs for 10–15-min to provide an adequate window of time to capture effects on EPSC amplitude ( Baldi et al., 2016 ). Make sure R a is closely monitored during the drug exposure period.…”

“…Phosphocreatine, a regenerative energy source increasingly included in internal solution recipes, can be used to adjunct cellular energy demands ( Baldi et al., 2016 ). If these solutions fail to improve cell longevity, considering switching to a K + -based internal solution that more closely resembles the physiological intracellular environment ( Williams and Mitchell, 2008 ).…”