Alcohol and Sedative-Hypnotics Lecture

This set of vocabulary flashcards covers the historical, pharmacological, and physiological aspects of alcohol and absinthe consumption as detailed in the lecture transcript.

Sedative-hypnotics and anxiolytics

A diverse group of compounds, including alcohol, barbiturates, and benzodiazepines, that depress the CNS and behavior, showing additive effects and cross-tolerance.

Methanol

A toxic form of alcohol also known as wood alcohol that is converted by alcohol dehydrogenase to formaldehyde and then formic acid, causing blindness, coma, or death.

Fermentation

A process where yeasts consume sugars to produce ethanol and $CO_2$, naturally limited to alcohol concentrations of up to $15\%$ because alcohol eventually kills the yeast.

Distillation

A process used to produce spirits by exploiting the lower boiling point of alcohol compared to $H_2O$; the vapor is evaporated and condensed in a still to reach higher concentrations.

Binge drinking

Defined as consuming $5$ or more drinks for men, or $4$ for women, in a single session.

Blood Alcohol Content (BAC)

The standard measure of alcohol in the body, expressed as grams of alcohol per $100\,ml$ of blood; for example, the legal driving limit in England and Wales is $0.08\,g/100\,ml$.

Margin of Safety (Alcohol)

The ratio between a recreational dose and a lethal dose; for alcohol, a BAC of $0.2-0.3\,g/100\,ml$ indicates high intoxication, while a BAC of $0.35-0.5\,g/100\,ml$ is potentially lethal.

Sucrose fading procedure

A method used to initiate alcohol self-administration in animals by gradually replacing a sucrose solution with ethanol over many days.

REM rebound

An increase in REM sleep during withdrawal from alcohol, which initially aids sleep onset but interferes with normal sleep patterns.

Alcohol dehydrogenase

An enzyme located in the stomach and liver responsible for breaking down the majority of ingested alcohol.

Antabuse (Disulfiram)

A prescription medicine that inhibits acetaldehyde dehydrogenase, causing increased levels of acetaldehyde which lead to flushing, nausea, and increased heart rate if alcohol is consumed.

Microsomal ethanol oxidizing system (MEOS)

A metabolic pathway involving the cytochrome $p450$ family of liver enzymes; it normally handles $5-10\%$ of alcohol metabolism but can account for $50-60\%$ with chronic use.

Delirium tremens

A severe and potentially fatal withdrawal syndrome from chronic alcohol use characterized by seizures, hallucinations, tremors, and autonomic disruption.

Korsakoff syndrome

A condition resulting from vitamin $B_1$ deficiency due to chronic heavy alcohol use, leading to damage in the mammillary bodies and thalamus, causing confusion and amnesia.

Apoptosis

Programmed cell death or 'self-destruction' that can be triggered in the developing brain by alcohol, barbiturates, or benzodiazepines, likely due to actions at $GABA_A$ and $NMDAR$ receptors.

Thujone

A toxic component found in wormwood used to make absinthe; it acts as a $GABA_A$ receptor antagonist by blocking $Cl^-$ currents, which can cause convulsions at high doses.

Alcohol

Alcohol (ethanol) is a central nervous system depressant that is rapidly absorbed after oral ingestion, mainly through the stomach and small intestine. Because it is both water- and lipid-soluble, it easily crosses the blood–brain barrier and quickly enters the brain. Alcohol primarily enhances GABAA_AA​ receptor activity, increasing chloride influx and inhibiting neuronal firing, which produces sedation, anxiolysis, impaired coordination, and slowed cognition. It also inhibits NMDA glutamate receptors, reducing excitatory neurotransmission and impairing learning and memory.

Alcohol activates the mesolimbic dopamine pathway by increasing dopamine release from the ventral tegmental area (VTA) to the nucleus accumbens (NAc), contributing to reward, euphoria, and addiction. As blood alcohol concentration rises, effects progress from relaxation and disinhibition to motor impairment, respiratory depression, coma, and death. Chronic alcohol use causes neuroadaptations in GABA and glutamate systems, leading to tolerance and withdrawal symptoms such as tremors and seizures.

Alcohol is mainly metabolized in the liver by alcohol dehydrogenase (ADH), which converts ethanol into acetaldehyde, and aldehyde dehydrogenase (ALDH), which converts acetaldehyde into acetate. Small amounts are excreted unchanged in breath, urine, and sweat.