BEHAVIORALNEUROSCIENCE

Neuroscience- scientific study of the nervous system

Neurons- carries neurotransmitters that is passed on to the other neurons, muscles, heart, brain

- It has 2 specialized extensions;o One is for receiving electric signalso The other, longer extension, is for transmitting electric signals.

Parts of the neurons

1. Nucleus- powerhouse of the neuron; provide food and energy2. Cell Body(or Soma)- provides fuel, manufactures chemicals and maintains the entire neuron

working together.3. Dendrites- receive signals from other neurons, muscles and sense organs4. Axon- carries signals away from the cell body to neighbouring neurons, organs and muscles5. Myelin Sheath- prevents interference from electric signals generated in adjacent axons.6. End Bulbs (or Terminal Bulbs)- stores neurotransmitters used to communicate with

neighbouring cells7. Synapse- is an infinitely small space( 20-30

bilionths of a meter) that exist between an end bulb and its adjacent body organ (heart), muscles, (head) or cell body. This is where the neurotransmitters cross to information.

Neurotransmitters- chemicals made by neurons and then used for communication between neurons during the performance of mental or physical activities.

Neurotransmitters- they play a role in the way we behave, learn, feel, and sleep. And some play a role in mental illness.

End bulbs

Neurotransmitters

1. Acetylcholine- involved in involuntary movements, learning, memory and sleepa. Too much will lead to depressionb. Too little will lead to dementia

2. Dopamine- correlated with movement, attention, learninga. Too much will lead to schizophreniab. Too little will lead to depression, muscular rigidity & tremors found in Parkinsons’

disease3. Norepinephrine- associated with alertness, eating

a. Too little will lead to depressionb. Too much will lead to schizophrenia

4. Epinephrine- involved in energy, glucose, metabolisma. Too little will lead to depression

5. Serotonin- play a role in mood, sleep, appetite, impulsive and aggression behavioura. Too little will lead to depression, anxiety, OCDb. Some anti-depressants medication increase the availability of Serotonin; used to treat

depression, anxietyc. Happy neuron

6. GABA (Gamma-Amino Butyric Acid)- inhibits excitation and anxietya. Too little will lead to anxiety, anxiety disorderb. Some anti-anxiety medication increase the availability of GABA; used to treat anxiety

7. Endorphins- pain relief and feelings of pleasure

BEHAVIORAL GENETICS

Study of how inherited genes contribute to abnormal behaviour

Genotype- total genetic makeup, composed of genes

Genotype- example: DNA structure

Phenotype- observable behavioural profile

Phenotype- example: eye color

4 Methods of Behavioral Genetics

1. Family Method (index cases/probards)- studying a family member, usually the one who seeks medical attention. This way they can trace the genetic disorder found in their family.

a. Parents; sister-brother- share 50% genesb. Grandparents; aunts-uncles- share 25% genesc. Great-grandparents; great aunts-uncles- share 12.5% genes

d. General population share very few genes

2. Twin Method(concordance)- presence of the same trait in twins

Monozygotic (identical twins) Dizygotic (fraternal twins) 1 egg cell is fertilized by 1 sperm There is a division of the zygote They always have the same gender They share 100% of genes

2 different egg cells are fertilized by 2 different sperm

There are two separate zygotes They may be same or of different gender They share 50% of genes

3. Adoptees Method(controls environment)- evaluate genetic and environmental influence on phenotype

4. Linkage Analysis (future directions)- serve as a way of gene testing