When investigating the mechanisms of neural communication and the impact various drugs can have on this its important to take into consideration what these actually mean and whereabouts in the body are the main components. The word neural communication consists of how neurons communicate with each other through their physiological process, and drugs consist of chemicals, substances or medicines that have a physiological and/or psychological effect on the brain and body. Within this essay I will look at what main parts of the body are associated with neural communication and I will explain how they interact as well as function to create the central nervous system, I will distinguish why the central nervous system itself is important and how altering it can have drastic changes; I will then go on to show how these are effected by drugs and what consequences this has.
Its foremost important to consider where neural communication begins, to understand this we have to start at the very beginning. The brain itself has numerous nerve cells which connect to various pathways in the body- in this case that would happen to be the central nervous system (CSN). The brain gives and receives information over nerves attached to the spinal chord and whilst this isn’t needed for all reflex movements its key in others i.e. physical responses to hot objects. The CSN is protected by firstly the blood-brain barrier which prohibits the entrance of any toxins to the brain via the blood, this occurs due to the blood barrier being tightly packed with blood vessel walls, also protection of the CNS by being surrounded by vertebrae, meninges and cerebrospinal fluid (Pinel, 2011).
Building up these nerve cells we have neurons- which transmit signals to other neurons around the nervous system through electro-chemical signals, these work collectedly with Glial cells which feed support to the neurons by offering physical and systematic support. In this case we will focus more on interneurons which transmit messages between themselves and transport information between the motor and sensory neurons and these can be located in the brain, eye and the spinal chord itself (Brodal, 2010; p 5-17). There are four key parts to a neuron which demonstrate how the neural communication process takes place. The soma is accountable for interpreting messages from other neurons through dendrites which are connected to the soma, they initially receive the messages and pass them on, as well as this the soma is also key in the safeguarding of the cell i.e. keeping control of a stable metabolism and overall wellbeing. We then arrive at the nerve fiber also known as the axon, these then transport the messages from the soma to the cells that the neurons are attempting to communicate with and this is known as action potential. Action potential is protected by the insulation of myelin which stops the scampering and quick uncoordinated movement of messages as well as rising the speed to improve efficiency of the message, the action potential or the firing of the axon is the process taking into account swift changes in electrical charge of the axon. Finally, we arrive at the terminal buttons which belongs to the presynaptic neuron, these are situated at the ends of the axon (also known as twigs), these emit neurotransmitters which is a chemical substance which allow the message to be delivered chemically to the postsynaptic neuron.
The way inter-communication happens between neurons is through the use of the synapse – this co-joins the terminal button to the membrane of another neuron transferring chemicals also known as neurotransmitters. The main two neurotransmitters of dopamine and serotonin help to either depolarize or hyperpolarize the neuron that the synapse is joining too this works by the receiving neuron working to reuptake the neurotransmitter. However, if the synapse has to reach over a far distance to connect the two neurons it can be disturbed by the disruption of the glial activities (Palay, 1956).
Drugs as a whole work by either stimulating receptors or preventing the presynaptic neuron from passing neurotransmitters through the synapse. The way in which this works is them allowing the passing or prevention of ions to leave the neuron (Martin, Carlson & Buskist, 2013).
An example of this is them directly effecting the reward pathway within the brain, in other words they target the neurotransmitter dopamine. Dopamine is the main reward pathway as well as being a hormone it’s the main factor that impacts an individuals feeling of pleasure. However, when taking a drug this can work in place of the chemical neurotransmitter, therefore interfering with the balance of this chemical to make it imbalanced and therefore disrupting behavior of the typical neural communication. An example of this is the use of conventional antipsychotic drugs in the treatment of schizophrenia, these bind to dopamine receptors but don’t actually stimulate them and consequently because of this these are known as antagonists, this therefore has the effect that it reduces stimulation of dopamine particularly in D2 receptors; doing this reduces the amount of dopamine transmitted to the postsynaptic neuron decreasing and by doing this it therefore stops the brain receiving this excess of dopamine delaying the effects which is thought to cause schizophrenia when there is an excess eliminating the symptoms (Wiley & Sons, 2001).
We can also consider the role of the drug cocaine, this attaches or binds itself to the receptor and inhibits and restraints reuptake this means that therefore stimulates and causes more activity to the postsynaptic neuron meaning more of the neurotransmitter gets released i.e. in this case more dopamine is released as the effect of the neurotransmitter is increased lengthening the effect making the experience of taking the dopamine more pleasurable to the individual taking the drug as it enhances the feeling of pleasure as the postsynaptic neuron receives more dopamine as well as increasing motor skills, this also demonstrates why those with Parkinson’s disease are more likely to receive dopamine enhancing drug treatments to improve motor skills as its believed through research those with the disease have a low sensitivity in dopamine receptors ( Aguilar, Ferrari, Munoz, Paris, Zecca & Zucca, 2014).
As well as cocaine, hallucinogens have an effect on the CNS by acting as an agonist. Instead of effecting dopamine however these effect serotonin receptors, an example of this is LSD’s; these prohibit serotonin from entering into the brain through the bloodstream, the structure of the LSD is too similar from the structure of serotonin for the brain to be able to differentiate between them and this tricks the brain into thinking the LSD is in fact serotonin and is passed across the synapse along with the original serotonin or instead of the actual serotonin increasing the levels of serotonin within the central nervous system. Serotonins prime function as a neurotransmitter and hormone is to regulate mood, therefore when serotonin is higher mood is generally better; therefore, LSD’s as well as this often also has the effect of giving an individual hallucination, therefore an individual can experience things, most commonly i.e. auditory or visual stimuli that’s not actually real, therefore this additional of serotonin causes this effect.
We can also look at the effects of alcohol on neural communication. Alcohol effects the CNS in many different aspects by targeting a variety of receptors most commonly it effects N-Methyl-D-aspartate which is also knows as NMDA, this is effected by glutamate being decreased at the receptors when alcohol is induced, this has the effects of memory loss this is due to the lack of glutamate which is important for memory within the hippocampus- therefore by reducing the sensitivity of the receptors the glutamate isn’t as frequently released (Chastain, 2006).
When taking all of this into account in order to conclude on how neural communication works and the effects drugs can have on this, we can assume from theory and supportive research that it suggest that neural communication is a process that’s vital for our ability to move and process actions in order to carry out specific tasks or roles within the body , its important we take into account the specific orderly structure of this is prominently strategic and its important we do not alter this or it can have a drastic impact on our bodies and our psychological wellbeing; the way in which this works is by postponing or causing an excess of neurotransmission uptake in most cases. This is therefore significant as it can offer psychologists a deeper understanding of knowledge and can help to offer practical insight on how to control or how to understand the effects drugs can have on this and could offer insight into drug awareness and the implications this has on the body.