2-Deoxy-d-glucose reduces epileptiform activity by presynaptic mechanisms

Area of Science:

• Neuroscience
• Cellular Physiology
• Biochemistry

Background:

• 2-Deoxy-d-glucose (2DG) is a glucose analog known to inhibit glycolysis.
• 2DG exhibits both acute and chronic antiepileptic effects, but its precise mechanisms remain unclear.
• Understanding the acute effects of 2DG on neuronal properties is crucial for its therapeutic potential in epilepsy.

Purpose of the Study:

• To investigate the acute effects of 2DG on synaptic and membrane properties of CA3 pyramidal neurons.
• To elucidate the presynaptic versus postsynaptic mechanisms underlying 2DG's antiepileptic actions.
• To determine if 2DG's effects are use-dependent and related to neuronal activity levels.

Main Methods:

• Electrophysiological recordings of CA3 pyramidal neurons in vitro.
• Application of 2DG (10 mM) under varying extracellular potassium concentrations ([K+]o) (3.5 mM and 7.5 mM).
• Pharmacological isolation of excitatory and inhibitory postsynaptic currents (PSCs) and assessment of use-dependent uptake using tetrodotoxin (TTX).

Main Results:

• In elevated [K+]o (7.5 mM), 2DG significantly reduced epileptiform bursting frequency and PSC charge, with a greater impact on excitatory currents.
• 2DG decreased the frequency of spontaneous and miniature PSCs, indicating a presynaptic locus of action.
• The antiepileptic effects of 2DG were use-dependent, requiring prior neuronal activity for uptake and action.

Conclusions:

• 2DG acutely suppresses epileptiform activity through a presynaptic mechanism that is dependent on neuronal activity.
• Inhibition of glycolysis by 2DG represents a novel strategy to modulate neuronal metabolism and reduce abnormal network synchronization.
• These findings highlight the role of glycolysis in neuronal energetics during high activity states, relevant to seizure control.