Blood brain barrier occurs when normal blood circulation separates from brain extracellular fluid that is found in the nervous system. The condition occurs in capillaries and forms tight joints especially in capillaries that are not there in normal circulation. Microscopic objects are restricted in the diffusion by endothelia cells, as well as hydrophilic molecules from entering cerebrospinal fluid (Pardridge 2006). However, the diffusion of minute hydrophobic molecules is allowed including oxygen and carbon dioxide. It is hence important to determine which chemicals are psychoactive or not. The cells that are in the barrier are responsible for the carrying of metabolic products that include glucose and proteins. The blood brain barrier also has a thick basement membrane as well as astrocytic endfeet (Kobiler 2001).
The sympathetic and parasympathetic nervous systems have different functions and operate in opposition. Together, they create balance in the body and its operations to ensure normal activity. A good example is when the heart gets a neural stimulation originating from the parasympathetic nervous system, there is a reaction and the heart beat rate slows down. On the other hand, when the heart gets a neural stimulation occurs from sympathetic neural system, the heart beat rate increases. When the autonomic nervous system is not in order, a problem occurs in the body. When there is extra stimulation of the sympathetic nervous system problems occur, such as anxiety and disturbances in digestion. Incase the parasympathetic nervous system is over stimulated, it can lead to low blood pressure. Psychoactive drugs alter normal neural stimulation and hence can hinder the balance between sympathetic and parasympathetic nervous systems (Sherwood 2012).
Neurons can be termed as the building blocks found in a person’s nervous system and they differ from different cells found in the body. The communication of neurons occurs as a result of an electrochemical process, where stimuli are received by sensory receptors. The stimuli is altered into a code and transported to the brain through the use of neurons, where the neurons found in the brain interpret the code. There occurs some changes in electrical properties popularly known as action potential and hence information is moved through dendrites and axons. A messenger connects with a receptor to activate an action potential and an electrical signal is initiated and generated via the neuron. When the sent signal gets to the end of an axon, a neurotransmitter is sent and the whole process starts again. If psychoactive substances enter synapses, it can alter how neurons interact as it changes the state of the electrochemical process that occurs during neurons interactions (Goldstein 2008).
The phrase ‘drugs don’t get you high’ means that certain drugs can have an effect on the nervous system that can be mistaken for ‘highness’. Natural drugs are those that are extracted directly from their source e.g. a plant or animals and no chemicals are added, an example is the aloe vera plant. Synthetics drugs are entirely man made and are developed from chemicals which emulate the performance of natural drugs, for example Piriton. Designer drugs are made for a specific target market to meet specific needs and are not produced for mass sales, for example Ketamine (Smith 1987).
Different people have different allergies and personal differences in their neural activities and hence similar drugs can have different effects on people. The ability of an individual to enjoy finer things in life is meditated through neurotransmitters. Drugs create an imbalance in the nervous system yet some safe activities can have close to the same effect without taking drugs. They lead to discharge of euphoriants naturally and cause the same amount of pleasure as drugs. They include exercise, good nutrition, invention, adventure, play, doing what you love, and sensual pleasure.