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Introduction to Psychobiology - Part 6 (A Neurotransmitter known as Acetylcholine)

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For more information about psychobiology, please check out "Physiology of Behavior," by Neil Carson
In this post we will cover a neurotransmitter known as Acetylcholine (ACh)



Acetylcholine (ACh)

This is thought to be the first discovered neurotransmitter by Otto Loewi (1).  To the right a drawing of a rat's brain and its acetylcholine pathway can be seen. ACh can be found in the peripheral nervous system(PNS) and the central nervous system (CNS). In the PNS it is involved with neuromuscular junction (2). This is where an axon reaches a muscle (3). Here the ACh causes EPSPs. This is excitatory postsynaptic potential and it refers to the action that increases the probability of an action potential occuring. On the other hand, IPSPs inhibit postsynaptic potentials (4). In the CNS, ACh in the basal forebrain is involved in perceptual learning and memory. In the Medial Septum, specifically the Hippocampus, ACH is also involved in learning and memory. In the Dorsolateral Pons, it…

Introduction to Psychobiology - Part 5 (Drug Effects)

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For more information about psychobiology, please check out: "Physiology of Behavior," by Neil Carlson


We mentioned before that drug effects are the biological and behavioral outcomes produced by introducing drugs into the body. Now we will introduce a concept known as drug-response curve that will connect to past material.This is refers to a graph that displays up to which point there is an the maximum effect obtained (1). In the picture on the right we can observe that the blue line represents the desired effect, in this case the analgesic effect, of morphine. Meanwhile, the red line describes when the dose of a drug produces a negative outcome, in this case the depressive effect. To measure when a drug is safe, we utilize (there are other methods to measure safety) the therapeutic index. This is the ratio between two numbers. The first one is the amount of a dose needed in order for 50% of a sample to obtain the desired effect of a drug, the second number is obtained by cal…

The Five Lectures of Freud: An Introduction to Psychoanalysis

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Sigmund Freud, a neurologist and the founder of psychoanalysis, made his first and only trip to the United States in 1909 (Jay, 2016). Stanley Hall, who was the first person to receive a PhD degree in psychology in the U.S., and the first president of the American Psychological Association, had invited Freud to Clark University to lecture on psychoanalysis (Encyclop√¶dia Britannica, 2016c). The lectures were part of the university celebrating its twentieth anniversary in which prominent figures spoke about their field (Burnham, 2012). The purpose of this essay is to explore each of Freud’s lectures in detail  in order to introduce psychoanalysis.  Before describing the lectures, it is important to understand how Freud mapped the mind. He divided it into three parts twice. The first time, he categorized it into the conscious, preconscious, and unconscious (Freud, 1938). The conscious layer contains everything that an individual is aware of, such as immediate physical experience. For…

Introduction to Psychobiology Part 4 (Psychopharmacoloy/Drugs)

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Psychopharmacology
For more information about biopsychology, please check out "Physiology of Behavior" by Neil Carson.

Drugs. Today we are going to talk about drugs. Psychopharmacology is the study of drugs (now it sounds redundant). We are going to explore how they affect mental processes and behavior.
Let's start with the basics: what is a drug? Neil Carson, the author of "Physiology of Behavior" defines a drug as "an exogenous chemical not necessary on normal cellular functioning that significantly alter the functions of certain cells of the body when taken in relatively low doses (1)." Or in simpler terms a chemical that changes the normal functions of the body. We'll tackle this definition one step at a time. Exogenous means outside an organism (2). This makes a reference that there are chemicals inside the body that alters normal somatic functions, but the definition of drugs only focuses on the external ones. We use the term drug effects when…

Introduction to Psychobiology Part 3 (Supporting Cells)

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Anterograde and Retrograde Axoplasmic TransportFor more information about biopsychology, please check out "Physiology of Behavior" by Neil Carson
Before I start I want to cover axoplasmic transport


If you saw the pictures from part 2 (http://hbookreviews.blogspot.com/2016/04/introduction-to-psychobiology-part-2.html), there was something called microtubules that we did not cover. They are a bundle of protein filaments with two main functions (1). One of them is to form the cytoskeleton, which gives each neuron its shape. The other function is to engage in axoplasmic transport. This is the process in which substances are transported along the axon. Kinesin, which is a protein, carries the substance. If the movement is from the body of the cell towards the terminal buttons, the process is called anterograde and if it is from the terminal buttons to the soma it's called retrograde transport (Antero- means towards and retro means backwards).
Supporting CellsMost people think th…

Introduction to Psychobiology Part 2 (Internal Structure of Neurons)

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Internal StructuresFor more information about biopsychology, please check out "Physiology of Behavior" by Neil Carson.
In part one we explored the parts of neurons, now we will look inside of them. Maybe you will remember this if you ever took biology. We'll start from the outside and end up on the center of the cell. 
First we have the membrane, which is a double layer of lipid molecules that mark the borders of the neurons. Like a customs officer, it is at the point of entry and decides what comes in and what comes out. 
Then we have the cytoplasm, which is a semi-liquid (thick) substance inside of the cell (1). The enzymes act as a catalyst to either separate or unite substances.
Ribosomes are produced by the nucleolus and they are responsible for the production of proteins (2) translated from mRNA ((1) We call this process protein synthesis). Chromosomes are made up of proteins and a single molecule of DNA ((3) Short for deoxyribunocleic acid). They are found in the nuc…

Neurons - Introduction to Psychobiology (Part 1)

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Structure and Functions of Cells of the Nervous SystemFor more information about biopsychology, please check out "Physiology of Behavior" by Neil Carson.


We'll start the series by talking about the cells of the nervous system, specifically neurons. These cells are located within the two structures that make up the central nervous system (CNS), the spinal cord and the brain, and they process information (1). These cells can be categorized by function and structure. In the former, neurons are divided into three categories depending on whether they process somatosensory information, motor information, or if they aid in the communication from a sensory to a motor neuron (4). For example, sensory neurons process experiences such as a touching sensation on the skin. On the other hand, motor neurons send information from the CNS to body parts such as muscles in order to create movement. Fun Fact: It is estimated that there are around 100 billion neurons in the brain (4). In add…