Cannabidiol reduces synaptic strength and neuronal firing in layer V pyramidal neurons of the human cortex with drug-resistant epilepsy

The use of cannabidiol (CBD) as an alternative pharmacological approach for the symptomatic management of epilepsy has gained attention due to its potential efficacy, particularly in drug-resistant cases of epilepsy. Although multiple studies have described that CBD reduces neuronal hyperexcitabilit...

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Main Authors: Vladimir A. Martinez-Rojas, Luis A. Márquez, Christopher Martinez-Aguirre, Isabel Sollozo-Dupont, Félix Iván López Preza, Monserrat Fuentes Mejía, Mario Alonso, Luisa Rocha, Emilio J. Galván
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Language:English
Published: Frontiers Media S.A. 2025-07-01
Series:Frontiers in Pharmacology
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Online Access:https://www.frontiersin.org/articles/10.3389/fphar.2025.1627465/full
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author Vladimir A. Martinez-Rojas
Luis A. Márquez
Christopher Martinez-Aguirre
Isabel Sollozo-Dupont
Félix Iván López Preza
Monserrat Fuentes Mejía
Mario Alonso
Luisa Rocha
Emilio J. Galván
Emilio J. Galván
author_facet Vladimir A. Martinez-Rojas
Luis A. Márquez
Christopher Martinez-Aguirre
Isabel Sollozo-Dupont
Félix Iván López Preza
Monserrat Fuentes Mejía
Mario Alonso
Luisa Rocha
Emilio J. Galván
Emilio J. Galván
author_sort Vladimir A. Martinez-Rojas
collection DOAJ
description The use of cannabidiol (CBD) as an alternative pharmacological approach for the symptomatic management of epilepsy has gained attention due to its potential efficacy, particularly in drug-resistant cases of epilepsy. Although multiple studies have described that CBD reduces neuronal hyperexcitability, the mechanistic basis of CBD remains a topic of ongoing research. In this study, we provide an electrophysiological portrayal of CBD’s effects on the glutamatergic transmission and intrinsic excitability of layer V pyramidal neurons of the human neocortex resected from drug-resistant epilepsy patients. The perfusion of CBD transiently depressed the field excitatory potential amplitude elicited in layer I/II and recorded in layer V without altering the paired-pulse ratio, suggesting a postsynaptic locus of action for CBD. Cortical slices perfused with 4-aminopyridine exhibited an increased number of spontaneous synaptic events that were abolished in the presence of CBD. At the cellular level, whole-cell patch-clamp recordings showed that CBD decreased the excitability of layer V pyramidal neurons, as evidenced by changes in the somatic input resistance, the membrane time constant, the hyperpolarization-induced “sag” conductance, the rheobase current needed to elicit an action potential, and the firing discharge in response to depolarizing current steps. Consistent with the last observation, CBD decreased the amplitude of the TTX-sensitive inward currents without altering the kinetics of the macroscopic outwardly directed currents. CBD washout restored the passive and active electrophysiological properties of pyramidal neurons. Collectively, these experiments demonstrate that CBD decreases the neuronal excitability of human cortical neurons from patients with drug-resistant epilepsy.
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spelling doaj-art-b016fa79eaa44729af57e0f1aaa8b2e42025-08-20T03:51:30ZengFrontiers Media S.A.Frontiers in Pharmacology1663-98122025-07-011610.3389/fphar.2025.16274651627465Cannabidiol reduces synaptic strength and neuronal firing in layer V pyramidal neurons of the human cortex with drug-resistant epilepsyVladimir A. Martinez-Rojas0Luis A. Márquez1Christopher Martinez-Aguirre2Isabel Sollozo-Dupont3Félix Iván López Preza4Monserrat Fuentes Mejía5Mario Alonso6Luisa Rocha7Emilio J. Galván8Emilio J. Galván9Departamento de Farmacobiología, Cinvestav Sur, Mexico City, MexicoDepartamento de Farmacobiología, Cinvestav Sur, Mexico City, MexicoDominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United StatesInstituto Nacional de Perinatología, Isidro Espinosa de los Reyes, Mexico City, MexicoDepartamento de Farmacobiología, Cinvestav Sur, Mexico City, MexicoDepartamento de Farmacobiología, Cinvestav Sur, Mexico City, MexicoInternational Center for Epilepsy Surgery, HMG-Coyoacán Hospital, Mexico City, MexicoDepartamento de Farmacobiología, Cinvestav Sur, Mexico City, MexicoDepartamento de Farmacobiología, Cinvestav Sur, Mexico City, MexicoCentro de Investigaciones sobre el Envejecimiento, CIE, Mexico City, MexicoThe use of cannabidiol (CBD) as an alternative pharmacological approach for the symptomatic management of epilepsy has gained attention due to its potential efficacy, particularly in drug-resistant cases of epilepsy. Although multiple studies have described that CBD reduces neuronal hyperexcitability, the mechanistic basis of CBD remains a topic of ongoing research. In this study, we provide an electrophysiological portrayal of CBD’s effects on the glutamatergic transmission and intrinsic excitability of layer V pyramidal neurons of the human neocortex resected from drug-resistant epilepsy patients. The perfusion of CBD transiently depressed the field excitatory potential amplitude elicited in layer I/II and recorded in layer V without altering the paired-pulse ratio, suggesting a postsynaptic locus of action for CBD. Cortical slices perfused with 4-aminopyridine exhibited an increased number of spontaneous synaptic events that were abolished in the presence of CBD. At the cellular level, whole-cell patch-clamp recordings showed that CBD decreased the excitability of layer V pyramidal neurons, as evidenced by changes in the somatic input resistance, the membrane time constant, the hyperpolarization-induced “sag” conductance, the rheobase current needed to elicit an action potential, and the firing discharge in response to depolarizing current steps. Consistent with the last observation, CBD decreased the amplitude of the TTX-sensitive inward currents without altering the kinetics of the macroscopic outwardly directed currents. CBD washout restored the passive and active electrophysiological properties of pyramidal neurons. Collectively, these experiments demonstrate that CBD decreases the neuronal excitability of human cortical neurons from patients with drug-resistant epilepsy.https://www.frontiersin.org/articles/10.3389/fphar.2025.1627465/fullcannabidiolhuman cortexlayer V pyramidal neuronpatch-clamp recordingsion channels
spellingShingle Vladimir A. Martinez-Rojas
Luis A. Márquez
Christopher Martinez-Aguirre
Isabel Sollozo-Dupont
Félix Iván López Preza
Monserrat Fuentes Mejía
Mario Alonso
Luisa Rocha
Emilio J. Galván
Emilio J. Galván
Cannabidiol reduces synaptic strength and neuronal firing in layer V pyramidal neurons of the human cortex with drug-resistant epilepsy
Frontiers in Pharmacology
cannabidiol
human cortex
layer V pyramidal neuron
patch-clamp recordings
ion channels
title Cannabidiol reduces synaptic strength and neuronal firing in layer V pyramidal neurons of the human cortex with drug-resistant epilepsy
title_full Cannabidiol reduces synaptic strength and neuronal firing in layer V pyramidal neurons of the human cortex with drug-resistant epilepsy
title_fullStr Cannabidiol reduces synaptic strength and neuronal firing in layer V pyramidal neurons of the human cortex with drug-resistant epilepsy
title_full_unstemmed Cannabidiol reduces synaptic strength and neuronal firing in layer V pyramidal neurons of the human cortex with drug-resistant epilepsy
title_short Cannabidiol reduces synaptic strength and neuronal firing in layer V pyramidal neurons of the human cortex with drug-resistant epilepsy
title_sort cannabidiol reduces synaptic strength and neuronal firing in layer v pyramidal neurons of the human cortex with drug resistant epilepsy
topic cannabidiol
human cortex
layer V pyramidal neuron
patch-clamp recordings
ion channels
url https://www.frontiersin.org/articles/10.3389/fphar.2025.1627465/full
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