Assignment Prompt & Instructions
Please read and respond to at least two of your peers' initial postings. You may want to consider the following questions in your responses to your peers:
– Compare and contrast your initial posting with those of your peers.
– How are they similar or how are they different?
– What information can you add that would help support the responses of your peers?
– Ask your peers a question for clarification about their post.
– What most interests you about their responses?
Please be sure to validate your opinions and ideas with citations and references in APA format.
### Reply from Erica OQuin
Describe the chemical and electrical processes used in neurotransmission.
The chemical and electrical processes are ways the brain uses to communicate actions to the rest of the body. The difference between the two are how they transmit this information. Chemical synapses utilize neurotransmitters to relay messages via a small gap that results in durable and intricate communication. In chemical transmission, neurotransmitters are released from presynaptic neural cells to postsynaptic receptors, (Pereda A. E., 2014). Erroneous amounts of specific neurotransmitters have been identified to contribute to various neurological disorders such as, Parkinson disease, schizophrenia, depression, and Alzheimer disease, (Pereda A. E., 2014). Electrical synapses is a more direct, simple, and faster form of communication that sends information by way of electrical signals directly through gap junctions, (Borroto-Escuela et al., 2024). Electrical synapses occur in the cytoplasm of adjoining cells that are directly connected by clusters of intercellular channels.
– Why are depolarizations referred to as excitatory postsynaptic potentials and hyperpolarization as inhibitory postsynaptic potentials?
Depolarizations are referred to as excitatory postsynaptic potentials because they promote the probability that an action potential will be fired in the postsynaptic cell. In contrast, hyperpolarization is identified as an inhibitory postsynaptic potential because it decreases the chances of an action potential. In both scenarios, the principle is the same as neurotransmitters bind to receptors, but the determining factor depends on the type of receptor that will result in either depolarization or hyperpolarization, (Purves D, Augustine GJ, Fitzpatrick D, et al., 2001).
– What are the differences between absolute and relative refractory periods?
The absolute refractory period is known as a duration of time where a neuron is nonreactive to any stimuli after the start of an action potential, (Sheffler Z., Reddy V., and Pillarisetty L. 2025). The relative refractory period is what happens following the absolute refractory period where the neurons membrane potential is hyperpolarized. During hyperpolarization, the chances of an action potential is decreased, (Jankowska, E., Kaczmarek, D., & Hammar, I. 2022).
Resources:
Borroto-Escuela, D. O., Gonzalez-Cristo, E., Ochoa-Torres, V., Serra-Rojas, E. M., Ambrogini, P., Arroyo-García, L. E., & Fuxe, K. (2024). Understanding electrical and chemical transmission in the brain. _Frontiers in cellular neuroscience_, _18_, 1398862. [https://doi.org/10.3389/fncel.2024.1398862Links to an external site.](https://doi.org/10.3389/fncel.2024.1398862)
Jankowska, E., Kaczmarek, D., & Hammar, I. (2022). Long-term modulation of the axonal refractory period. _The European journal of neuroscience_, _56_(7), 4983–4999. https://doi.org/10.1111/ejn.15801
Pereda A. E. (2014). Electrical synapses and their functional interactions with chemical synapses. _Nature reviews. Neuroscience_, _15_(4), 250–263. [https://doi.org/10.1038/nrn3708Links to an external site.](https://doi.org/10.1038/nrn3708)
Purves D, Augustine GJ, Fitzpatrick D, et al., editors. Neuroscience. 2nd edition. Sunderland (MA): Sinauer Associates; 2001. Excitatory and Inhibitory Postsynaptic Potentials. Available from: https://www.ncbi.nlm.nih.gov/books/NBK11117/
Sheffler ZM, Reddy V, Pillarisetty LS. Physiology, Neurotransmitters. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: [https://www.ncbi.nlm.nih.gov/sites/books/NBK539894/Links to an external site.](https://www.ncbi.nlm.nih.gov/sites/books/NBK539894/)
### Reply from Talibah Tyson
**Neurotransmitters Discussion**
The chemical and electric process of neurotransmission is characterized by an electrical impulse in the first neuron that is changed into a chemical signal between the first and second neuron via a process called excitation-secretion coupling. Chemical information gets signaled between the first and second neurons to change genetic functioning and molecules. This happens by converting the chemical information in the first neuron back to an electrical impulse in the second neuron (Stahl, 2021.)
Depolarizations are referred to as excitatory postsynaptic potentials because it increases the likelihood that an action potential might occur. It moves the membrane potential closer to threshold. Hyperpolarization is referred to as inhibitory postsynaptic potential because it decreases the likelihood of an action potential occurring. This brings the membrane potential away from the threshold (Akter, 2024.)
The differentiation between absolute and relative refractory periods is during an absolute refractory period it is not possible to create another action potential. A relative refractory period limits the amount of action potential that a neuron can fire (Akter, 2024.)
**References**
Akter, F. (2024). _Neuroscience for neurosurgeons_ (3rd ed.). Cambridge University Press. [https://books.google.com/books?id=cjXuEAAAQBAJ&lpg=PA72&ots=_zeACuUTQN&dq=absolute%20and%20relative%20refractory%20period%20neurotransmission&lr&pg=PA72#v=onepage&q&f=falseLinks to an external site.](https://books.google.com/books?id=cjXuEAAAQBAJ&lpg=PA72&ots=_zeACuUTQN&dq=absolute%20and%20relative%20refractory%20period%20neurotransmission&lr&pg=PA72#v=onepage&q&f=false)
Stahl, S. M. (2021). _Stahl's essential psychopharmacology: Neuroscientific basis and practical applications_ (5th ed.). Cambridge University Press.