UNIT IV: BIOLOGICAL BASIS OF BEHAVIOR

BIOLOGICAL BASIS OF BEHAVIOR

Neuron Structure

Cell Body

• Nucleus contained inside
• Cell life support center

Dendrites

• Receives messages from other cells
• Finger like

Axon

• Passes messages away from the cell body to other neurons, muscles, or glands.

Myelin Sheath

• Covers the Axon of Neurons
• Helps with Neutral impulses and speed.

Neural Impulses

• Electrical signal travelling down the axon

Terminal Branches of Axon

• Form junctions with other cells.

What is the Synapse?

• The space in between the cell

How does a Neuron Fire?

• It is an electrochemical process 
• Electrical inside the neuron
• Chemical outside the neuron (in the synapse in the form of a neurotransmitter)

What is Action Potential?

• Action Potential is what the "firing" is called

All or None Response

• The idea that either the neurons fire or does not- No halfway firing
• Like a gun- "You either fire or you don't"

What is a Neurotransmitter?

• Chemical messages released by terminal buttons through the Synapse.

How do we study the brain?

• Accident
• Lesions (Remove or destroy parts of the brain)

TOOLS USED

EEG

• Electroencephalogram
• Detects brain waves through their electrical output. 
• Used mainly in sleep research

CAT SCAN

• Computerized Axial Tomography
• 3-D X-ray of the brain
• Good for tumor locating but tells us nothing about the function.

MRI

• Magnetic Resonance Imaging 
• Takes still pictures

PET SCAN

• Positron Emission Tomography
• Measures how much of a chemical the brain is using. (Usually glucose consumption)
• Combination of the PET scan and MRI

What is the Corpus Callosum?

• Connects the two hemispheres of the Cerebral Cortex

What happens when the Corpus Callosum is removed?

• Split brain patient

Define Brain Plasticity

• The ability of our brain to form new connections after neurons damage.

Types of Neurotransmitters

Acetylcholine (ACH)

• Deals with motor movement and memory 
• Lack of ACH had been linked to Alzheimer's

Dopamine

• Deals wit motor movement and alertness
• Lack of Dopamine has been linked to Parkinson's Disease
• Too much has been linked to Schizophrenia.

What is Serotonin?

• Involved with mood control
• Lack of Serotonin has been linked to clinical depression

What is Endorphins?

• Involved in pain control
• Many of our most addictive drugs deal with Endorphins

What is GABA?

• The brains major inhibitory neurotransmitter
• Causes Schizophrenia and Insomnia

What is Glutamate?

• Glutamate creates links between neurons that form the basis of learning and long term memory.
• If taken in excess it can cause over stimulation of the brain resulting in a Seizure
• Avoid foods with MSG

What are Norepinephrine's?

• It is a fight or Flight
• Controls alertness and arousal
• Elevates the heart rate, circulation and respiration 
• Probably can put you in a depressed mood.

Drugs can be...

• Agonist (Makes neurons fire)
• Antagonist (Stops Neurons from firing)
• Reuptake Inhibitors (Block Neurotransmitters from transmitting)