Response2: How genetics (nature) and the environment (nurture) affectsynaptic development

Inthe nervous system, a synapse refers to the specific structures thatallow for the transfer of electrical activity from one cell to theother. This transmission is usually in the form of nerve to nerve orto muscle. The region between the post and pre-synaptic membrane isreferred to as the synaptic gap or cleft. Once an action pulse hasbeen stimulated, there is no direct communication between pre andpost-junction cells because there are chemical mediators known asneurotransmitters. Research has established that even in adults,these synapses can adapt to a new environment (Iversen, 2013).Additionally, as is the case with young children who are alwaysforming new neural networks, synapses allow new connections to beformed and reorganize old ones, and this eventually results inbehavior adjustments. Recent advances in molecular and geneticsbiology has shown that some inherited developmental brain disorderscan affect the growth and development of synapses and as a result,affecting their functionality. Both genetic and environmental factorshave an important role to play in shaping synaptic development.

Examplesof such genetic disorders include Rett syndrome, autism, and tuberoussclerosis. Individuals suffering from fragile X syndrome which isassociated with 30% of autism exhibit abnormal production of aparticular protein known as FMRP which affects the development ofother neurons (Eagly &amp Wood, 2013) Without FMRP, the neurons willdevelop abnormally long and spindle dendritic spines. These extendedstructures are usually associated weak communication and connectionbetween neurons and automatically affect synapse development andfunctionality. Glutamate receptors whose role is to engage inpush-pull balancing acts do not function effectively without FMRP andas a result, their signals may interfere with the healthy developmentof synapse. Synaptic pruning is a good illustration of how theenvironment affects synapse development. In neuroscience, synapticconnection can either decrease or increase. Synaptic pruning affectslearning, reasoning, memorizing and planning (Singh, 2012).Individuals who engage their minds a lot have more neuralconnections, and this results in higher intelligence.

Response3: Major synaptic transmission malfunctions

Thefour major steps of synaptic transmission include

1.Synthesis and storage of neurotransmitters Here, there is the makingof molecules from their precursors. This state is dependent on enzymeactivities to catalyze interactions. An example of an excitatorymolecule is Acetylcholine whose precursors are choline and acetate.There is also the synthesis of neuropeptide at this stage. One thingthat can happen which result in either dysfunctional ornon-functioning synaptic transmission can be the deletion ofchromosome 22 as in the case of Phelan-McDermid syndrome (PMS). Genedeletion of any of the component of the neural system results in theformation of defective or non-functioning neurotransmitter.

2.The second stage is the release stage whereby the transmittermolecule is allowed into the synaptic cleft. Sometimes synaptictransmission may not work correctly (dysfunctional synaptictransmission) or does not function at all (non-functioning synaptictransmission) because of the blockage of calcium ions which willresult in inhibition of neurotransmitter.

3.The third step of synaptic transmission is the binding stage. Here,there is the attachment of the transmitter molecule to a receptor.This technique observes the key and lock system and is receptorspecific. One of the causes of dysfunctional or non-functioningsynaptic system is the introduction of a competing receptor. This isthe mechanism adopted by some types of poisons.

4.The last step is removal and stage which involve both uptake andbreakdown of the transmitter molecule so that they do not continue tobind to the receptor molecules. Once reuptake is completed, thetransmitter is broken down for use in the first step. In this stage,the synaptic transmission may not work correctly (dysfunctionalsynaptic transmission) or does not function at all (non-functioningsynaptic transmission) due to the presence of reuptake inhibitorssuch as some medications like Antidepressant drugs.

Response4: How dysfunctional or non-functioning synaptic transmission affectan individual’s behavior or mental processing

Dysfunctionalor non-functioning synaptic transmission is caused by the activitiesof neurotransmitters. Once an action potential has been initiated,the impulse travels from the first nerve cell to the next. Some ofthe contributing factors to neurotransmitters dysfunctions includegenetic modification, blockage of calcium ions and inhibitors amongothers. Research has affirmed that both inhibitory and excitatorysynapse play a very crucial role in processing information to thebrain (Bray, 2014). The effects of dysfunctional and non-functionalsynaptic transmission result in the neurodegenerative diseases asParkinson’s disease, Huntington’s disease and AD. Autism spectrumdisorders. These disorders are associated with behavioral problemssuch as deficits in communication, delay in language and stereotype.Consequently, mental retardation is as a result of defective synapseand results in hypersensitivity, hyperactivity, and anxiety.

Alldiseases such as insomnia, depression, and Parkinson’s disease areall associated with an imbalance in neurotransmitters. This can becaused by stress. When an individual is subjected to both physicaland emotional stress, neurons tend to use large quantities ofneurotransmitters to manage the ongoing stress. As the situationcontinue to escalate, the nervous system is worn out and thusdepleting the neurotransmitter supply. Similarly, genetics can alsobe credited for this imbalance. Some people are born withneurotransmitter deficiencies and excesses. Alzheimer’s disease ischaracterized by memory deficits, gradual decline in intellectual andcognitive functions and thus symbolizing poor development of neuralnetworks.

Response5: Medications and Enzymatic degradations

Medicationscan be used to correct synaptic transmissions that are not workingcorrectly. An example is the selective serotonin uptake inhibitors.The modes of action of SSRIs is that they act at the 5 HT transporterprotein (Bray, 2014). These group of medications bind to the carrierprotein and immediately blocks the process of reuptake ofneurotransmitters. Enzymes are essential natural catalysts inphysiological reactions. Enzymatic degradation refers to themechanisms through which neurotransmitters become inactive bychanging its structure so that it is no longer recognized by thereceptor. Usually, an enzyme binds to the neurotransmitter and as aresult, breaking it apart. Since receptors are very specific, itcannot fit in the receiving cell.

Antidepressantsprovide an excellent example of how medications affect enzymaticdegradation. Antidepressants have three distinct processes by whichthey act on neurotransmitters. These processes includeneurotransmitter degradation, neurotransmitter binding, and reuptakeprocesses. Inhibiting neurotransmitters degradation results ingeneral influx in the neurochemical quantities in the synapse. Theincrease results in more binding at postsynaptic receptors. Monoamineoxidase found in both neurons and cells are the ones tasked withdegrading monoamine neurotransmitters after its absorption. A specialcategory of drugs called monoamine oxidase inhibitors (MAOIs) acts byinhibiting this enzyme and hence resulting in elevated levels ofneurotransmitters in the synaptic cleft.

Response6: what is the difference between epsp and ipsp

EPSPstand for excitatory postsynaptic potential it is defined asexcitatory because it fires an action potential

IPSPstand for inhibitory postsynaptic potential. Additionally, it is akind of synaptic potential that hinders the postsynaptic neuron fromgenerating an action potential.

InEPSP, there is a flow of positively charged ion directed towards thepostsynaptic cell. It results in the opening of ligand-gated ionchannels.

IPSP,on the other hand, refers to the flow of negatively charged towardsthe postsynaptic cells. The result is the closure of ligand-gated ionchannels.

EPSPis associated with a decrease in outgoing, positive charges, andIPSPS are at times caused by positive charge outflow.

Response7: Why learning about synaptic transmission is helpful in developinga better understanding of psychology

entails the scientific study of mental processes and human behaviors.Although people have different characters, it is evident that bothare determined in the neural system. Various factors such as geneticsand environmental surroundings affect ones behaviors. Through thestudy of synaptic transmission, it is possible to understand thecause of some behaviors or conditions. For instance, research hasshown that genetic mutations can influence can affect thetransmission of information from one neuron to the other through thesynaptic cleft. Consequently, it is evident that by understandingvarious aspects synaptic transmission one can explain why some peoplehave higher IQ that others. Understanding more about synaptictransmission helps people to account for the cause of aggressivebehavior and depression in some people. Lastly, this knowledge cancontribute to devising the most appropriate methods to manageconditions such as stress.

Thisassignment has helped me distinguish between acquired and innatebehaviors. Additionally, there are several conditions that affecthuman behavior which arises from a defective gene that hindersimpulse transmission, and these are usually displayed in the form ofhyperactivity, sadness, depression and by memory deficits in someindividuals. As an individual, this assignment has helped meunderstand the significance of feeding my mind with educational andrelevant materials from an early age. Research states that neuralnetworks enhance learning, it is, therefore, evident that when onetrains his or her mind to think, he or she can create more of thesesynaptic transmission pathways. Lastly, I have learned howantidepressants bring about their effects in the neural system.


Bray,N. (2014). Neurotransmitters: Dopamine tone depends on DAT.&nbspNatureReviews Neuroscience,&nbsp15(8),495-495.

Eagly,A. H., &amp Wood, W. (2013). The nature–nurture debates 25 yearsof challenges in understanding the psychology of gender.&nbspPerspectiveson Psychological Science,&nbsp8(3),340-357.

Iversen,L. (Ed.). (2013).&nbspDrugs,neurotransmitters, and behavior.Springer Science &amp Business Media.

Singh,I. (2012). Human development, nature and nurture: Working beyond thedivide.&nbspBioSocieties,&nbsp7(3),308-321.

Steen,R. G. (2013).&nbspDNAand destiny: Nature and nurture in human behavior.Springer.