Pleasure, from cocaine

The pleasurable feelings from cocaine use last only 15-30 minutes if it is snorted and only five to 10 minutes if cocaine is smoked or injected into the veins. When the high is over, the user feels tired, sluggish, and low. ... 

Cocaine is a very addictive drug. Cocaine is a stimulant—it directly affects your brain. Cocaine stimulates certain nerve cells in the brain, producing feelings of intense pleasure. Users talk about feeling carefree, or relaxed, or utterly in control. But this artificial stimulation comes with a price tag. The high from cocaine lasts only from five to 20 minutes, and you will need more and more cocaine each time you try to match the feelings of that first, initial experience. Cocaine causes severe mood swings and irritability. 

The pleasure derived from using tobacco is linked to the stimulation of dopamine-dependent neurotransmitter pathways in the brain, particularly in the meso-limbic system. The precise nature of this link remains controversial, but many of the neurophysiological processes underlying nicotine addiction are common to other addictive drugs with diverse pharmacological actions such as opiates, cannabis, alcohol and cocaine. 

For years, scientists have known that cocaine interferes with the brain s dopamine system. Dopamine is a neurotransmitter—a chemical that passes nerve impulses from one nerve cell to another, and dopamine is associated with movement, emotional response, and the ability to experience pleasure. Research indicates that serotonin transporters are also inactivated with cocaine use. Serotonin is another neurotransmitter, and adequate levels are associated with well-being. Low levels of serotonin in the brain have been linked to depression. Inactivation of dopamine and serotonin transporters leads to receptor over-stimulation and the high. Continued use of cocaine can result in long-term changes in the brain chemistry as receptors decrease in number. These changes can be persistent and even irreversible, and may be responsible for the feeling of depression that lasts long after withdrawal. 

Cocaine is a local anesthetic with a peripheral sympathomimetic action that results from inhibition of transmitter reuptake at noradrenergic synapses (see Chapter 6 Introduction to Autonomic Pharmacology). It readily enters the central nervous system and produces an amphetamine-like effect that is shorter lasting and more intense. The major action of cocaine in the central nervous system is to inhibit dopamine reuptake into neurons in the "pleasure centers" of the brain. These properties and the fact that it can be smoked, "snorted" into the nose, or injected for rapid onset of... 

These natural reward centers have developed over the course of evolution to reinforce useful behaviors (e.g., pleasure, sexual satisfaction, eating, and drinking). It is believed that drugs such as cocaine and amphetamine directly stimulate these centers, while opiates free the pathways from inhibitory control. Nicotine, on the other hand, reaches the brain in as little as 10-20 seconds, where it stimulates nicotine receptors to cause dopaminergic neurons to release large quantities of dopamine. After a few hours, dopamine levels decline, causing withdrawal symptoms to readily appear (e.g., anxiety, irritability, and inattentiveness). When cigarette smokers say they need a smoke to steady their nerves, what they really mean is that they have to contend with nicotine withdrawal. 

As we have learned, depending on the method through which cocaine is introduced into your body (either snorted, injected, or inhaled), the drug travels a quick route to its ultimate goal your brain. In the brain, cocaine ultimately undergoes a critical transformation from a source of pleasure to a desperate craving or need. 

Apart from the Puritan anti-pleasure ethic, inebriants like morphine, heroin, and cocaine acquired a bad reputation as a consequence of widespread use in so-called... 

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