Nicole Garcia Borjas
PSY1012
Neuroscience and Behavior – 8/22/19
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Neurons are the basic building blocks of the nervous system
- Conduct electricity in body
Made of 3 parts
- Soma (Cell body)
- Dendrite
-Axon (covered in Myelin), main tube and branches on the sides
SOMA
- houses the nucleus
- nucleus houses genetic material
 Chromosomes
-looks like an X
- made of long strings of genes
- Genes: subsections of the chromosomes that produce proteins
- 46 in body (23 from each parent)
- located in every neuron within your nervous system
 Genes & Cellular Signaling
- genes create hormones
- hormones are released from the cell into the surrounding blood supply
- hypothalamus and pituitary gland are two common areas that generate hormones
- Hormones control behaviors:
- feeding (hunger, fullness)
- emotions
- sexual responsiveness (pre/post puberty)
- wakefulness (sleep-wake cycle)
 Dendrite
- Bring charged particles (ions) into a neuron
- Lead to the soma where they are accumulated about 1 millisecond
 Soma
- if there is sufficient signal strength (+10mV) during this 1 millisecond period, then
this cell will produce its own signal at the axon hillock
 Axon
- Each new action potential develops in the axon hillock
- Each one has the same strength (+40 mV)
- Action potentials from different cells can have different speeds
- Cells fire by the All- or-None law
- if it doesn’t fire, it remains at -70
-only place where electricity exists
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Interconnecting Neurons
Vesicles filled with neurotransmitters in the presynaptic neuron are pushed against the
cell wall
Vesicles merge with the cell wall
Neurotransmitters cross the synaptic gap
- They land on their binding sites at the postsynaptic membrane
- Mechanical properties of binding cause them to be released and move toward the
presynaptic membrane
- The neurotransmitter undergo reuptake.
Basic rules of Psychopharmacology
- Shapes of NT’s &receptors
- Each NT has its own chemical shape and therefore a unique receptor with which It
binds
- Behavior altering drugs- drugs that have shapes similar to the naturally occurring
NT’s
- Drugs from these classes may also modify psychological characteristics for treatment
purposes as well
-Depression
- Anxiety
- Hallucinations
- Thought disorders
- Neurotransmitter Pathways
- Each neuron typically carries only one class of neurotransmitter
- Neurons generally only communicate w similar neurons
- This produces NT pathways in the brain
- NT pathways are anatomically isolated from the surrounding cellular pathways
NT, pathways &brain processing
- Each area of the brain is involved in one general classification of activity
- Sensory processing or motor processing
- NT pathways will be a part of one of these areas
- NT type, specific brain area, and sensory/motor processing are strongly
correlated
Interconnecting Neurons
 Sensory neurons- neurons that bring information into the brain from sensory receptors
- Sensory pathway
 Motor neurons- send information from the brain to the muscles
- Motor pathway
 Interneurons- link sensory neurons to motor neurons
- Brain circuits
 Input-Output Nervous System
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All sense reception signals pass through specific unchanging pathways in the
nervous system
- All motor output signals pass through specific unchanging pathways in the
nervous system
- The interneuron pathways in the brain change regularly
This gives us a sensory input >>>motor output system w/intervening adaptable
connections
Neuroplasticity refers to these adaptable connections everything it does to repair or
rewire itself. The brain rewires itself every day, usually when asleep (REM sleep)
Neuroanatomy
 2 main branches of the nervous system
 Central nervous system – brain/spinal cord
 Peripheral nervous system – everything else
Neurons can be lined up and regrown (ex. Gotham)
 All encased in bone, and surrounded by cerebral spinal fluid, always used and
working 100% of the time >> (everything is available to be used)
 Brain Stem
 Medulla – heart rate & breathing
 Cerebellum – coordination & balance
 Reticular Formation – alertness
 Thalamus – central location of all sensory input, involved in sensory
integration
Limbic System – controls emotions
- Expression & detection of emotional behavior
- Always working, all behavior has emotional component
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Reward Center – located in limbic system
- Any behavior consequence w/ reward will increase in frequency
- drug addt
- learned relations through social attention (ex someone says thank you
and it makes you feel good)
- Damage or drugs that reduce its activity cause a reduction in pleasant
emotions
- long term use of MDMA (Ecstasy) causes reductions in dopamine and
serotonin concentrations in reward center >>>> permanent low-grade
depression
Cortex
- 4 lobes
- Parietal – touch and vestibular input
- Occipital – visual input
- Temporal –auditory & gustatory/ olfactory input
- Frontal – planning and model output
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Each lobe has a primary and association cortex
-Primary cortexes are used for initial sensory input or final motor output