IS THE BRAIN ONE BIG COMPUTER?

IS THE BRAIN ONE BIG COMPUTER?

The brain functions as an incredibly sophisticated electrical and chemical machine, using a seamless two-step process to transmit and process information via its fundamental unit, the neuron (nerve cell).¹

The communication within the brain relies on the following cycle:

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⚡ 1. The Electrical Signal (Action Potential)²

Information travels rapidly within a single neuron as an electrical signal called an action potential (or nerve impulse).³

• Basis: The neuron maintains an electrical charge difference, or resting membrane potential, across its cell membrane, established by an unequal distribution of positively and negatively charged ions (primarily Sodium (⁴$Na^+$), Potassium (⁵$K^+$), and Chloride (⁶$Cl^-$)) inside versus outside the cell.⁷

• Firing: When a neuron receives enough stimulation from its neighbors to reach a specific voltage threshold, voltage-gated ion channels rapidly open.⁸

  • This causes a sudden, massive influx of positive ions (⁹$Na^+$) into the cell, which momentarily reverses the electrical charge from negative to positive—this is the action potential.¹⁰

• Propagation: This electrical spike then travels quickly and in an all-or-nothing fashion down the length of the neuron's transmitting fiber, the axon, until it reaches the end terminal.¹¹

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🧪 2. The Chemical Signal (Neurotransmitters)¹²

Once the electrical signal reaches the end of the axon, it must cross a tiny gap, the synapse, to communicate with the next neuron.¹³ This is where the signal converts from electrical to chemical.¹⁴

• Conversion and Release: When the action potential arrives at the axon terminal, it triggers the release of specialized chemical messengers called neurotransmitters into the synaptic cleft (the gap).¹⁵

• Crossing the Synapse: The neurotransmitters quickly diffuse across this gap and bind to receptors on the receiving neuron's dendrites.¹⁶ This binding is specific, like a key fitting a specific lock.¹⁷

• Effect: The action of the neurotransmitter on the receptor determines the next step for the receiving neuron:¹⁸

  • Excitatory Neurotransmitters (e.g., Glutamate) push the receiving neuron's voltage toward its firing threshold, making it more likely to generate its own action potential.¹⁹

  • Inhibitory Neurotransmitters (e.g., GABA) push the voltage away from the firing threshold, making it less likely to fire.²⁰

By constantly integrating thousands of these excitatory and inhibitory chemical inputs, the receiving neuron determines whether to generate its own electrical signal, thereby perpetuating the communication throughout the brain's vast neural circuits.²¹

Key Chemical Messengers

Neurotransmitter	Primary Role(s)
Glutamate	Major Excitatory neurotransmitter; learning and memory.
GABA (Gamma-Aminobutyric Acid)	Major Inhibitory neurotransmitter; calming, anxiety regulation.
Dopamine	Reward, motivation, motor control.
Serotonin	Mood, sleep, appetite.
Acetylcholine	Muscle contraction (PNS), attention, memory (CNS).

Diagram of Brain

Is the brain like a big phone system or is it one big computer with ON or OFF states ? Neither of the above is correct.

Let's look at the brain as an orchestra. In an orchestra, you have different musical sections. There is a percussion section, a string section, a woodwind section, and so on. Each has its own job to do and must work closely with the other sections. When playing music, each section waits for the conductor. The conductor raises a baton and all the members of the orchestra begin playing at the same time playing on the same note. If the drum section hasn't been practicing, they don't play as well as the rest of the orchestra. The overall sound of the music seems "off" or plays poorly at certain times. This is a better model of how the brain works. We used to think of the brain as a big computer, but it's really like millions of little computers all working together. Diagram of Brain

IS THE BRAIN ONE BIG COMPUTER? VIDEO

THE BRAIN: AN ELECTRICAL AND CHEMICAL MACHINE

THE BRAIN: AN ELECTRICAL AND CHEMICAL MACHINE

The brain functions as an incredibly sophisticated electrical and chemical machine, using a seamless two-step process to transmit and process information via its fundamental unit, the neuron (nerve cell).¹

The communication within the brain relies on the following cycle:

---

⚡ 1. The Electrical Signal (Action Potential)²

Information travels rapidly within a single neuron as an electrical signal called an action potential (or nerve impulse).³

• Basis: The neuron maintains an electrical charge difference, or resting membrane potential, across its cell membrane, established by an unequal distribution of positively and negatively charged ions (primarily Sodium (⁴$Na^+$), Potassium (⁵$K^+$), and Chloride (⁶$Cl^-$)) inside versus outside the cell.⁷

• Firing: When a neuron receives enough stimulation from its neighbors to reach a specific voltage threshold, voltage-gated ion channels rapidly open.⁸

  • This causes a sudden, massive influx of positive ions (⁹$Na^+$) into the cell, which momentarily reverses the electrical charge from negative to positive—this is the action potential.¹⁰

• Propagation: This electrical spike then travels quickly and in an all-or-nothing fashion down the length of the neuron's transmitting fiber, the axon, until it reaches the end terminal.¹¹

---

🧪 2. The Chemical Signal (Neurotransmitters)¹²

Once the electrical signal reaches the end of the axon, it must cross a tiny gap, the synapse, to communicate with the next neuron.¹³ This is where the signal converts from electrical to chemical.¹⁴

• Conversion and Release: When the action potential arrives at the axon terminal, it triggers the release of specialized chemical messengers called neurotransmitters into the synaptic cleft (the gap).¹⁵

• Crossing the Synapse: The neurotransmitters quickly diffuse across this gap and bind to receptors on the receiving neuron's dendrites.¹⁶ This binding is specific, like a key fitting a specific lock.¹⁷

• Effect: The action of the neurotransmitter on the receptor determines the next step for the receiving neuron:¹⁸

  • Excitatory Neurotransmitters (e.g., Glutamate) push the receiving neuron's voltage toward its firing threshold, making it more likely to generate its own action potential.¹⁹

  • Inhibitory Neurotransmitters (e.g., GABA) push the voltage away from the firing threshold, making it less likely to fire.²⁰

By constantly integrating thousands of these excitatory and inhibitory chemical inputs, the receiving neuron determines whether to generate its own electrical signal, thereby perpetuating the communication throughout the brain's vast neural circuits.²¹

Key Chemical Messengers

Neurotransmitter	Primary Role(s)
Glutamate	Major Excitatory neurotransmitter; learning and memory.
GABA (Gamma-Aminobutyric Acid)	Major Inhibitory neurotransmitter; calming, anxiety regulation.
Dopamine	Reward, motivation, motor control.
Serotonin	Mood, sleep, appetite.
Acetylcholine	Muscle contraction (PNS), attention, memory (CNS).

Diagram of Brain

Let's start looking at the building blocks of the brain. As previously stated, the brain consists of about 100 billion cells. Most of these cells are called neurons. A neuron is basically an on/off switch just like the one you use to control the lights in your home. 

It is either in a resting state (off) or it is shooting an electrical impulse down a wire (on). It has a cell body, a long little wire (the "wire" is called an axon), and at the very end it has a little part that shoots out a chemical. This chemical goes across a gap (synapse) where it triggers another neuron to send a message. 

There are a lot of these neurons sending messages down a wire (axon). By the way, each of these billions of axons is generating a small amount of electrical charge; this total power has been estimated to equal a 60 watt bulb.

 Doctors have learned that measuring this electrical activity can tell how the brain is working. A device that measures electrical activity in the brain is called an EEG (electroencephalograph).

Each of the billions of neurons "spit out" chemicals that trigger other neurons. Different neurons use different types of chemicals. These chemicals are called "transmitters" and are given names like epinephrine, norepinephrine, or dopamine. Diagram of Brain

THE BRAIN: AN ELECTRICAL AND CHEMICAL MACHINE VIDEO :

Your Brain and What It Does

Your Brain and What It Does

Brain Information

AMYGDALA: Lying deep in the center of the limbic emotional brain, this powerful structure, the size and shape of an almond, is constantly alert to the needs of basic survival including sex, emotional reactions such as anger and fear. Consequently it inspires aversive cues, such as sweaty palms, and has recently been associated with a range of mental conditions including depression to even autism. It is larger in male brains, often enlarged in the brains of sociopaths and it shrinks in the elderly.

BRAIN STEM: The part of the brain that connects to the spinal cord. The brain stem controls functions basic to the survival of all animals, such as heart rate, breathing, digesting foods, and sleeping. It is the lowest, most primitive area of the human brain.

CEREBELLUM: Two peach-size mounds of folded tissue located at the top of the brain stem, the cerebellum is the guru of skilled, coordinated movement (e.g., returning a tennis serve or throwing a slider down and in) and is involved in some learning pathways.

CEREBRUM: This is the largest brain structure in humans and accounts for about two-thirds of the brain’s mass. It is divided into two sides — the left and right hemispheres—that are separated by a deep groove down the center from the back of the brain to the forehead. These two halves are connected by long neuron branches called the corpus callosum which is relatively larger in women’s brains than in men’s. The cerebrum is positioned over and around most other brain structures, and its four lobes are specialized by function but are richly connected. The outer 3 millimeters of “gray matter” is the cerebral cortex which consists of closely packed neurons that control most of our body functions, including the mysterious state of consciousness, the senses, the body’s motor skills, reasoning and language.
 
The Frontal Lobe is the most recently-evolved part of the brain and the last to develop in young adulthood. It’s dorso-lateral prefrontal circuit is the brain’s top executive. It organizes responses to complex problems, plans steps to an objective, searches memory for relevant experience, adapts strategies to accommodate new data, guides behavior with verbal skills and houses working memory. Its orbitofrontal circuit manages emotional impulses in socially appropriate ways for productive behaviors including empathy, altruism, interpretation of facial expressions. Stroke in this area typically releases foul language and fatuous behavior patterns.

The Temporal Lobe controls memory storage area, emotion, hearing, and, on the left side, language.

The Parietal Lobe receives and processes sensory information from the body including calculating location and speed of objects.

The Occipital Lobe processes visual data and routes it to other parts of the brain for identification and storage.

HIPPOCAMPUS: located deep within the brain, it processes new memories for long-term storage. If you didn't have it, you couldn't live in the present, you'd be stuck in the past of old memories. It is among the first functions to falter in Alzheimer's.

HYPOTHALAMUS: Located at the base of the brain where signals from the brain and the body’s hormonal system interact, the hypothalamus maintains the body’s status quo. It monitors numerous bodily functions such as blood pressure and body temperature, as well as controlling body weight and appetite.

THALAMUS: Located at the top of the brain stem, the thalamus acts as a two-way relay station, sorting, processing, and directing signals from the spinal cord and mid-brain structures up to the cerebrum, and, conversely, from the cerebrum down the spinal cord to the nervous system.