The predominant effect of depressants is to depress, or deaden, neuronal activity. Consider anesthetics. They are so strong in their depressant action that beyond the state of general anesthesia that they induce, there lies only coma and death. It is believed that once anesthetics have been administered, they reach the brain and inhibit neuronal firing so much that consciousness is “lost.” Therefore it is clear that without adequate neuronal firing there can be no information processing or information conductance and hence no mindfulness. Here we have yet more proof that consciousness is bound up with the billionfold action of activated neurons in the brain.
If we take another depressant drug, like alcohol, we find that it too acts to inhibit neuronal firing throughout the brain, and hence consciousness becomes depressed or reduced. However, at low doses the opposite effect takes place, whereby there is a certain degree of psychological stimulation because of the initial depression of the inhibitory synapses, which, as you will recall, serve to diminish neuronal firing. However, soon after these inhibitory neurons are depressed, excitatory neurons begin to be depressed as well, and this effect comes to dominate the ensuing state of consciousness.
Not only do depressants inhibit neuronal firing in the brain, they also appear to depress the activity of the body’s other nerves, heart tissue, and muscle tissue. More specifically, depressants upset the functioning of the arousal centers in the brain such that psychological arousal and stimulation are diminished. In short, the quantity of consciousness is reduced due to a concurrent reduction in neuronal firing, and there is less informational patterning and less informational organization happening within the neuronal systems of the brain once a depressant drug has been introduced.
Stimulants have the opposite effect of depressants. Cocaine and amphetamines each work in virtually the same way, causing almost identical stimulatory effects like euphoria, an increase in alertness, an elevation of mood, and a reduction in fatigue. Indeed, cocaine is derived from the coca plant, the leaves of which are still chewed daily by millions of native South Americans precisely for the resultant psychological stimulation and reduction in perceived tiredness and hunger. This latter “productive” effect of the coca leaf explains the fact that while the sixteenth-century Spanish conquistadors outlawed the religious use of sacred mushrooms, peoples like the Incas were allowed to continue their practice of chewing coca leaves as long as they slaved away in Spanish gold mines.
Amphetamines are believed to mimic and increase the activity of the neurotransmitters noradrenaline and dopamine (the brain uses many different types of neurotransmitter), thus interfering with the normal synaptic functioning of neurons using these neurotransmitters. This happens partly because amphetamines are similar in molecular structure to both noradrenaline and dopamine. Because of this resemblance, amphetamines literally invade those neuronal areas where synaptic transmission with these transmitters occurs and increase the rate of impulse generation. Once this occurs, the typical “speeding” psychological responses take hold.
With cocaine a similar tale unfolds. In this case, however, it appears that cocaine inhibits the recycling (the “mopping up”) of noradrenaline and dopamine within synapses after they have done their work. Because of this selective interference, there are more neurotransmitters “hanging around” in synapses and therefore more of them to stimulate receiving neurons into excitatory action.
In both cases, the chief neurological effect is that of an increase in synaptic activity that causes stimulation of the nervous system. Again we see that the stimulating alteration in consciousness caused by these drugs is due to an increase in the information-processing activity of certain types of neuron, in this case, neurons utilizing noradrenaline and dopamine. Increased neuronal activity of this kind then generates the desired psychological stimulation, or “high.” It is important to bear in mind, however, that the increased neuronal activity in this case does not lead to any kind of profound visionary experience. Such radical phenomenology is restricted to psychedelics.
With tea and coffee, the active ingredient, caffeine, is believed to increase rates of cellular metabolism, thus making more energy available to cells. The net result of this action is once again an elevated rate of neuronal firing, which explains the subtle stimulatory properties of tea and coffee and their widespread use.
The third class of psychoactive substance on our list is opiates, which are derived from the opium poppy. The opiates are interesting for their variety of powerful effects. The worldwide painkiller morphine is an invaluable opiate, and its chemical isolation from the opium poppy radically revolutionized medicine and pain control. Morphine seems to selectively bind to opiate receptors in the brain, which suggests that the brain has its own pain-control mechanisms. Indeed, it has been proposed that acupuncture and hypnosis might be able to reduce pain because they encourage the brain to generate its own endorphins, which are natural opiate substances that bind to opiate receptors (endorphins are also believed to be the cause of the high often experienced after rigorous exercise). Once these opiate receptors are activated, the emotional perception of pain diminishes—as opposed to a diminishing of the actual pain impulses arriving from the site of injury. Along with opium and heroin (a semisynthetic compound), morphine also generates euphoria, and this is associated with the emotional changes wrought through the activation of the nervous system’s opiate receptors.
With the fourth class of drugs, the antipsychotics, we find synthetic compounds such as risperidone being used the world over to treat mental diseases, including schizophrenia. Perhaps the most common neuropsychological theory holds that schizophrenia results from an excess of the substance dopamine within the brain. Dopamine, of course, is a major neurotransmitter that we met when we looked at the neurological effect of stimulants.
The excess-dopamine explanation for schizophrenia is supported by the effects of risperidone, which can diminish the symptoms of this disease. Because risperidone operates partly by blocking dopamine receptors in the brain, it is logical to assume that an excess of dopaminergic neuronal activity lies at the heart of schizophrenia. This speculation leads to the intriguing conclusion that somehow an elevation in the activity of dopamine-using neurons is intimately bound with the strange delusions and belief systems of the unfortunate mind suffering from schizophrenia. By blocking the excess dopamine at the receptor sites, risperidone helps to block disorders of thought.
Here we have another strong clue about how to unravel the mysteries of the formation and emergence of complex consciousness—for schizophrenia is noted precisely for its disruptions of those higher levels of awareness that pertain to reality conception. Furthermore, these large-scale disruptions in thought appear to be nonrandom in that certain definite types of delusion are observed, often related to feelings of paranoia and the belief that one is being controlled by horribly malevolent external forces. If dopaminergic synaptic overactivity really is to blame for these global disorders of thought, we can begin to conceive how large patterns of abnormal neuronal firing yield large disorders of cognition, such as paranoid delusions and the like. If neuronal activity becomes too overactive and too “wild,” then the resultant firing patterns might well be “flawed,” which is to say that these patterns are essentially mistakes serving to mislead the experiencer. Or, if there is some negative disruption in the overall way in which the schizophrenic conceives reality, then the schizophrenic’s model of reality will provide a faulty contextual effect on ongoing neuronal activity.
Obviously the human brain is a finely tuned information-processing instrument. If the neuronal events substantiating some kinds of information processing are pushed too far from some criteria, or if neuronal events are “read” by an erroneous contextual system, faulty processing occurs, with its resultant negative disruption of consciousness.
Neuro-alchemical Magic
Finally we come to the class of compounds known as psychedelics or entheogens. Admittedly it has been a little tough getting here, yet the journey is worth it. We are now ready to home in even closer to the link between neuronal chemistry and consciousness. Entheogens are by far the most interesting of all known psychoactive substances, although precious little is known about exactly how they are able to generate such a remarkable array of psychological effects. Entheogens are often referred to by unwary clinicians as
