The Biological Basis of Behavior Chapter 2 Background

The Biological Basis of Behavior Chapter 2

Background 1/3 of humanity is dead 2. 3 billion have died Virus is spreading exponentially No vaccines or cures have been found Attempts to eradicate have been futile We are the last hope

Mission Statement You have been recruited because you are the best and brightest young minds, work well in groups, and most important of all, your creativity. We will be focusing on neuroscience as we have deduced that the brain plays a very important role in explaining zombie behavior. Your goal will be to become a medications development specialist and create a cure for the zombie plague that is destroying the world.

Over the course of this unit you must learn about the following to save our civilization: Neurons Neurotransmission Neurotransmitters Neuroanatomy Medications development

A Neuron is A specialized cell that receives information and transmits it to other cells.

Neurons: The Messengers About 100 billion neurons (nerve cells) in the human brain Neurons have many of the same features as other cells. Nucleus Cytoplasm Cell membrane What makes neurons unique is their shape and function.

Neuron under an electron microscope

Structure of Neurons Dendrites Carry information to the cell body from other neurons Cell Body (Soma) Contains nucleus Axon Carries information to the next cell Myelin Sheath Insulates the axon and speeds up the neural impulse

Make your own Neuron Dendrite Axon Soma (cell body) Nucleus Myelin Sheath Terminal Buttons Give your Neuron a name fit for a zombie film Give it some color, make it spooky

How does it work? Neurotransmission is a fancy name for two or more neurons communicating with each other.

The Neural Impulse: resting potential Neurons stay at rest with their sodium ions on the outside of the cell body (or soma) and potassium ions on the inside. The Neuron isn’t transmitting information

The Neural Impulse Neurons are no longer at rest when the sodium ions on the outside of the cell body rush in and potassium ions on the inside rush out.

The Neural Impulse: Action Potential Sudden, massive change in charge in the neuron Occurs when depolarization reaches the threshold of excitation Ions flow across cell membrane

The Neural Impulse The electrical impulse races down the axon

The Neural Impulse All-or-None Law A neuron either fires or it does not. When it does fire, it will always produce an impulse of the same strength. Intensity of a stimulus is coded by the frequency of action potentials.

The Neural Impulse Once the electrical impulse reaches the terminal button it triggers the vesicles (containing neurotransmitters), to move toward the bottom of the terminal button.

The Neural Impulse Neurotransmitters are released from terminal buttons and cross the tiny space between it and the next neuron called the synaptic gap.

The Synapse (Synaptic space) Tiny gap between neurons. The synapse is composed of the terminal button of one neuron, the synaptic space, and the dendrites or cell body of the receiving neuron

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Lets Simulate this process

Neurotransmi tters

Neurotransmitters A neurotransmitter is a chemical messenger that carries signals between neurons as well as other cells in the body. These chemicals are released from the end of one neuron and cross the synapse to receptor sites in the next neuron.

Transmission Between Neurons

Some Well. Known Neurotransmitt ers

Acetylcholine (ACH) It’s the most common neurotransmitter. It is located in both the central nervous and peripheral nervous system. It acts on basic autonomic and muscular functions Plays an important role in arousal and attention Loss of ACH producing cells is linked to Alzheimer’s

Dopamine Affects neurons associated with voluntary movement and plays a role in learning, memory, and emotions. Loss of dopamine-producing cells causes symptoms of Parkinson's.

Glutamate Is an excitatory neurotransmitter Plays a role in learning and memory Too much can cause seizures Malfunction of glutamate has also been associated with Alzheimer's

Epinephrine Also known as adrenaline Causes the feeling of being “revved up” or on edge Activates a “fight or flight” reaction in the autonomic nervous system

Serotonin Attention and other complex cognitive functions, such as sleep (dreaming), eating, mood, pain regulation Neurons which use serotonin are distributed throughout the brain, stomach and spinal cord Issues with this leads to Mood disorders like depression

GABA (gamma-aminobutyric acid) It’s the most important and common inhibitory neurotransmitter Stops the brain from becoming overexcited Too much may cause hallucinations

Endorphins Reduce pain by inhibiting or “turning down” neurons that transmit pain information

Neuro DANCE PARTY

Our brain evolved over time 1. Lizard Brain - Basic functions 2. Mammalian Brain - More complex feelings and reactions 3. Human Brain - Logic and reasoning

The Brain Stem or Hindbrain (The Lizard Brain) Activity in the brain stem is important for: *bodily activities essential to survival, such as changes in heartbeat and breathing *the focusing of attention *patterns of arousal (that is sleeping versus waking)

The Midbrain/ Limbic System (The Mammalian Brain) Located in the middle of the brain Associated with these behaviors: 1. Fighting 2. Feeding 3. Fleeing 4. Reproductive behavior * The part of the brain that regulates emotion

Important parts of the midbrain The Thalamus processes and relays movement and sensory information. It is a relay station, taking in sensory information and then passing it on to the cerebral cortex.

Important parts of the midbrain The hypothalamus connects with many other regions of the brain and is responsible for controlling hunger, thirst, emotions, and body temperature regulation.