Psychology Unit IV: Neurons

NEURONS

Nervous System

• starts with an individual nerve cell called a neuron

How does a Neuron fire?

• Resting Potential: slightly negative charge
• reach the threshold when enough neurotransmitters reach dendrites
• go into Action Potential (fire)

All-or-none response

• the idea that either the neuron fires or it does not - no part way firing
• like a gun

Neurotransmitters

• chemical messengers that a released by terminal buttons through the synapse

Types of Neurotransmitters

Achetycholine (ACH)

• deals with motor movements and memory
• lack of ACH had been linked to Alzheimer's disease 

Dopamine

• deals with motor movement and alertness
• lack of dopamine has been linked to Parkinson's disease
• too much has been linked to Schizophrenia 

Serotonin

• involved with mood control
• lack of serotonin has been linked to clinical depression

Endorphins

• involved in pain control
• many of our most addictive drugs deal with endorphins

Norepinephrine

• helps control alertness and arousal
• under supply: depression
• over supply: manic symptoms

GABA (gamma - aminobutytic - acid)

• major inhibitory neurotransmitters
• under supply: leads to tremors, seizures, and insomnia

Glutamate

• major excitatory; involved in memory 
• over supply: can overstimulate the brain leading to migraines (this is why some people avoid MSG in food)

Drugs Can Be

• Agonist: make neuron fire
• Antagonist: stop neural firing
• Re-uptake Inhibitors: block neurotransmitters from entering the neuron

Types of Neurons

Sensory (Afferent)

• take information from senses to the brain

Inter 

• take messages from sensory neurons to other parts of the brain or to motor neurons

Motor (Efferent)

• take information from the brain to the rest of the body