Calcium channel antagonists prevent adaptive responses to ethanol

Area of Science:

• Neuroscience
• Pharmacology

Background:

• Prolonged ethanol administration upregulates dihydropyridine-sensitive binding sites, associated with neuronal calcium channels.
• These calcium channels are implicated in the development of physical dependence on ethanol.

Purpose of the Study:

• To investigate the role of neuronal calcium channels in ethanol dependence and withdrawal.
• To evaluate the efficacy of dihydropyridine calcium channel antagonists in preventing ethanol tolerance and withdrawal.

Main Methods:

• Chronic ethanol administration in vivo.
• Assessment of dihydropyridine binding sites.
• Administration of dihydropyridine calcium channel antagonists with ethanol.
• Electrophysiological recordings of hippocampal slices to assess epileptiform activity.

Main Results:

• Chronic ethanol increased dihydropyridine binding sites, indicating neuronal calcium channel upregulation.
• Chronic co-administration of dihydropyridine antagonists with ethanol prevented tolerance and withdrawal syndrome.
• Upregulation of binding sites was also prevented by the antagonists.
• Ethanol-induced epileptiform activity in hippocampal slices was stereoselectively prevented by isradipine.

Conclusions:

• Neuronal calcium channels play a critical role in ethanol physical dependence, tolerance, and withdrawal.
• Dihydropyridine calcium channel antagonists are effective in preventing ethanol-induced neuroadaptations and withdrawal symptoms.
• Isradipine demonstrates stereoselective neuroprotective effects against ethanol-induced hyperexcitability.