Describe the physiological effects and mode of action of alcohol, nicotine, cocaine, methamphetamine, heroin, and marijuana. (pages 295-98)

Alcohol: Physiological effects include mild euphoria, relaxation, decreased inhibitions, and impaired motor function, memory, and decision-making. Its mode of action involves interacting with GABA receptors and inhibiting the neurotransmitter glutamate. Nicotine: Physiological effects comprise increased heart rate, blood pressure, alertness, and can improve memory/cognitive function. It acts on nicotinic acetylcholine receptors and stimulates neurotransmitter release. Cocaine: It causes increased alertness, energy, euphoria, blood pressure, heart rate, and body temperature. Cocaine inhibits the reuptake of dopamine, norepinephrine, and serotonin, increasing their synaptic cleft levels. Methamphetamine: Produces increased energy, alertness, and euphoria, but also severe physical and neurological damage. Its mode of action involves increasing the release of dopamine, norepinephrine, and serotonin while inhibiting their reuptake. Heroin: Creates euphoria, relaxation, pain relief, and depresses respiratory/nervous systems. It acts as an opioid agonist, binding to mu-opioid receptors, inhibiting pain signals, and releasing dopamine. Marijuana: Leads to relaxation, euphoria, altered perceptions, impaired memory, attention, and coordination. Its primary component, THC, acts on the endocannabinoid system by binding to CB1 and CB2 receptors, modulating neurotransmitter release.