BIOLOGICAL PSYCHOLOGY: NEUROTRANSMITTERS

Neurotransmitters: The Complete Guide to Brain Chemistry

The human brain is no less than a masterpiece. Interwoven through a lot of neurons, different features of the brain-their respective chemical messengers or neurotransmitters-regulate everything from respiration to creativity. Among others, neurotransmitters make up the chemical messengers in that system of communication lying within your brain. In return, it takes over command centers for the hippocampus, amygdala, and cortex as a means of emotional and intellectual control.

This text is going to empower the reader with insight into the anatomy of the brain, the neurotransmitter world, and their interaction in governing our behavior and emotions for optimal being.

Part I Neurotransmitters: The Human Brain

The human brain is a pretty complicated system made of billions of cells, or neurons, and how those neurons interact. To briefly consider the glory of its wonder, let's start by looking at three major areas:

1. The Hippocampus

• Location: Deep within the temporal lobes, it forms part of the limbic system.
• Function: Hippocampus is the very powerhouse of memory in the brain. It processes the short-term memories and helps them store as long-term memories.
• Functional Role in Navigation: Other than memory, hippocampus provides your spatial awareness. It helps in finding your way around you.

2. The Amygdala

• Location: This too forms part of the limbic system; the structure is near the shape of hippocampus.
• Function: It is almond-shaped. It acts as the 'emotional command' of your brain. Emotions ranging from fear and anger to a feeling of pleasure.
• Fight or Flight Significance: Amygdala plays a very important role in triggering survival instincts, especially when one goes through stress or danger.

3. The Cortex

• Location: It is the very outermost layer of the brain. The four major divisions are the frontal, parietal, occipital, and temporal lobes.
• Function: Owing to the higher-order functions that are made from the cortex, it includes reasoning, decision-making, and sensory processing.
• Specialized Areas: Specific tasks have been assigned to each lobe. Putting it better, the ocular lobe will decide on visuals while the frontal decides about planning and judgment.

These structures interact in complex ways to influence how we think of ourselves and feel about and behave in the world.

Part II Neurotransmitters: The Brain's Chemical Messengers

Armed with a general description of the brain's hardware, in this chapter we turn to a description of its software: neurotransmitters. These chemicals make communication between neurons possible and impact literally every aspect of our lives.

What is a Neurotransmitter?

Neurotransmitters represent the chemical messengers of the body. They permit signals to transcend synapses, the small gap between neurons. This is where the firing of the neuron will finally release the neurotransmitters to pour into the synaptic cleft whereby, they must hit receptors from the next neuron and can bind, the binding that determines but is not limited to the following specific responses: muscle movement, mood changes, or the thought process.

Neurotransmitters are brain chemicals that enable proper brain function and play a major role in activities ranging from heartbeat and digestion to mood and learning.

The Neurotransmission Process

Neurotransmitters are best understood as to how they work when the process is divided, step by step:

• Synthesis: Neurotransmitters are synthesized within the neuron itself. This is often out of dietary nutrients such as amino acids.
• Storage: Neurotransmitters stored within the presynaptic neuron in vesicular form.
• Release: With the firing of the neuron into the cell membrane, the vesicles start releasing the neurotransmitter within the synaptic cleft by the process of fusion.
• Binding: Neurotransmitters bind onto specific receptors on the postsynaptic neuron. The neuron then gives a response through it.
• Termination: Either the neurotransmitters are broken down by enzymes, reabsorbed into the presynaptic neuron, or diffuse away in order not to overexcite it.

Types of Neurotransmitters

Neurotransmitters are categorized depending on their action:

1. Excitatory Neurotransmitters

• Function: These activate neural activity.
• Examples: Glutamate-the key to learning, and acetylcholine- required for memory and muscle contraction.

2. Inhibitory Neurotransmitters

• Function: They dampen the nervous system and decrease neural activity
• Examples: GABA-promotes sleep, and glycine.

3. Modulatory Neurotransmitters

• Function: These alter the activities of thousands of neurons.
• Examples: Dopamine- reward and motivation, serotonin- maintain mood, noradrenalin (stress hormone).

Key Neurotransmitters and their Functions

1. Dopamine

• Function: It associated with reward, pleasure and with motor control.
• Imbalance: Gives rise to Parkinson's in low amount and Schizophrenia in high amount.

2. Serotonin

• Function: Maintains mood, appetite and sleep.
• Imbalance: Thought to be linked to Depression and Anxiety.

3. Acetylcholine

• Function: Deals with memory, learning, and movement of the muscles.
• Imbalance: Its deficiency is associated with Alzheimer's disease.

4. GABA

• Function: Reduces excitability to maintain calmness.
• Imbalance: Low levels anxiety and seizures.

5. Glutamate

• Function: It produces learning and memory.
• Imbalance: High amount of it is associated with neuro degenerative diseases like Alzheimer's.

6. Norepinephrine

• Function: The level of stress and alertness.
• Imbalance: Lower levels lead to symptoms of lethargy and depression.

7. Endorphins

• Role: These chemicals are naturally occurring painkillers and produce euphoria.
• Imbalance: With low levels, sensitivity to pain increases.

Neurotransmitters in Mental and Physical Health

Mental Health

Neurotransmitter imbalance implicated in a number of disorders:

• Depression: Generally related to low serotonin or norepinephrine.
• Anxiety: Low GABA can contribute to nervousness.
• Schizophrenia: Linked to excessive dopamine.

Physical Health

• Acetylcholine: Muscle contraction, decrease/increase in heart rate.
• Norepinephrine: Change in blood pressure based on amount of stress. 
• Dopamine: Assisted digestion and motor movement.

Factors Affecting Neurotransmitter Levels

• Dietary Intake: Dietary intake of amino acid, vitamin, and mineral precursors.
• Aerobic Exercise: Aerobic exercise may increase dopamine and endorphins.
• Sleep: Restores neurotransmitter systems.  
• Stress: Chronic stress depletes stores of neurotransmitters as in serotonin.
• Substance Abuse: Many drugs and alcohol disrupt neurotransmitter systems.

Ways to Improve Brain Health 

To encourage brain health and neurotransmitter function.

• Nutritional Correction: Add to your diet nuts, fish and leafy vegetables rich in nutrients.
• Physical Activity: Better the body movement, better neurotransmitter generation can occur in an individual.
• Prioritize Sleep: Sleep for 7 to 9 hours daily
• Manage Stress: Practice mindfulness meditation

The Future of Neurotransmitters Research

With the advance in neuroscience, new knowledge came to light about neurotransmitters. New emergent research fields like optogenetic and psychopharmacology review new ways of manipulating neurotransmitter systems with the purpose of treating such mental disorders as depression and post-traumatic stress or neurodegenerative pathologies.

Conclusion: Symphony of Brain Chemistry

Anatomy, via the brain and neurotransmitters, orchestrates it all in concert: everything from our actions down to thoughts to emotions. The hippocampus, amygdala, cortex-all of these beautifully and impressively choreograph higher-order functions, their neurotransmitters of dopamine and serotonin thereby fine-tuning emotions and responses.

Appreciation of this remarkable machinery, and information about decision-making, will be fostered by better understanding its parts in light of optimized physical and mental health.