Drug evaluations using neuronal networks cultured on microelectrode arrays

Area of Science:

• Neuroscience
• Pharmacology

Background:

• Cannabinoid agonists like anandamide (AN) and methanandamide (MA) are known to interact with the central nervous system.
• Understanding their effects on neuronal networks is crucial for neuroscience and drug development.

Purpose of the Study:

• To investigate the characteristic responses of neuronal networks to cannabinoid agonists AN and MA.
• To determine the dose-dependent effects and tissue specificity of AN and MA on neural activity.

Main Methods:

• Cultured spontaneously active neuronal networks from embryonic murine spinal cord and auditory cortex.
• Utilized substrate-integrated thin-film microelectrodes to record neural activity.
• Administered AN and MA at varying concentrations to assess dose-dependent effects.

Main Results:

• AN and MA reversibly inhibited spike and burst production in both spinal cord and auditory cortex neuronal networks.
• Cortical cultures showed equipotent responses to AN and MA (2.5 +/- 0.9 microM).
• Spinal cultures were more sensitive to AN (1.3 +/- 0.7 microM) than MA (5.8 +/- 1.2 microM).
• Methanandamide exhibited a biphasic effect: excitation at low doses (0.25-3.5 microM) and suppression at higher doses (4-7.1 microM).
• Palmitoylethanolamide did not affect network activity, suggesting receptor-specific action.
• Irreversible cessation of activity occurred at concentrations > 7 microM after 30 min exposure.

Conclusions:

• Cannabinoid agonists AN and MA exhibit potent inhibitory effects on neuronal network activity.
• Responses are dependent on the neuronal tissue type and the specific cannabinoid compound.
• Methanandamide displays complex, dose-dependent effects, including excitation and suppression.