Week 1A

History of Neuroscience

  • Behavioral Neuroscience: The study of the neural bases of psychological processes and behavior

    • Neural bases: how the brain network functions to produce mental activities

  • Neuroscience: the study of the nervous system



Historical Views on the Brain

  • Previously thought that emotions were controlled by the heart, could feel “emotions” there

    • ex. heart racing when you’re excited

  • Brain thought of as cooling system, didn’t hold importance

    • Heat rises to the top of the body


  • Galen (physician) linked damage to the head to changes in behavior

    • This observation linked the brain to behavior

      • Thought the brain controlled some portion of actions and thoughts


  • Ventricles (holes) in the brains & nerves observed that are linked to the body

    • Figured out that the brain controls movement

    • Thought that animal spirits travelled through the nerves; in the cerebral spinal fluid

    • Figured out that the nerves control the muscle movement


  • Discovered a link between electricity and muscle movement through the use of electrical impulses

    • This established that the brain is connected to movement



The Mind-Brain Problem

  • Dualism: the belief that the mind and body are different kinds of substance that exist on their own; distinct subjects

    • The idea that there is a non-physical mind and physical brain


  • Now, the mind is a physical process that is created from the brain

    • Thought of as a collection of processes of the brain; thinking, sensing, planning, feeling

  • Mental processes are happening because of brain processes

  • Relationship between the brain and the mind was supported by…

    • Drugs affecting the brain

      • Shows that behavior comes from the brain

    • Physical damage causing mental processes

    • Brain development issues leading to impaired cognition



Functional Lateralization

  • Confusion arises from the division of the brain and which portions of the brain controlled which behaviors

  • Case Study: Metal bar going through skull of a man

    • The man survived and experienced a change in his personality and became aggressive

  • Study show that a brain lesion change a part of mental functions

    • There was a particular change to the emotion regulation of the man but some were left in tact

    • Showed that different parts of the brain control different functions


  • Phrenology: Consider the brain to act as a type of muscle since different parts of the brain have different functions. The brain functions like a muscle where a bump on the skull will indicate a use of that portion of the brain

    • This theory is false



Historical Brain Analogies and Evolution

  • There have been analogies to compare the brain to modern inventions

    • Ex. The brain acts like a computer

      • Not completely true since there are competing faction in the brain that operate to perform different functions and not meet a single goal like a computer which has no inner forces that will produce a different result


  • The brain can be compared to something like the federal government (important)

    • Each person has different responsibilities and will interpret data differently and will have access to certain information

    • The brain can be thought of as a collection of modules that have their own goals

      • This can cause an inner conflict which leads to different result

    • At different moments certain portions of the brain might override the other

    • There are also checks and balances

      • The brain triggers us to breathe when we’re holding in our breath



Everything in neuroscience should be considered with a evolutionary brain

  • Our nervous system has evolved from organisms and are conserved in animals

    • There is a lot of knowledge to gain from studying animals, since the neural structure in animals apply to us

    • Some behaviors (like hair rising like in a cat) are shared between human as well which can be studied as well


  • Our brain has evolved to survive and reproduce

    • Thats why visual illusions are able to work on us

    • There are quirks in memory that might not allow us to remember specific details, since it evolutionary is not important to remember which tiger

      • Like when we’re attacked by a tiger we will remember the fact that we were attacked but no necessarily which of two tigers attacked us



Levels of Organization in Behavioral Neuroscience

  • Level Analysis, each component (level) work simultaneously to produce a behavior

    • Social Level (broad, people with people)

    • Organ Level

    • Neural System Level

    • Brain Region Level

    • Circuit Level

    • Cellular Level

    • Synaptic Level

    • Molecular Level


  • Nervous System → Subsystems → Circuits → Neurons



Nervous System → Biggest level of organization (Systems Neuroscience)

  • Is divided into different components, composed of neurons

  • It is used for movement, which had evolved from jellyfish which were the first animals to develop neurons and a nervous system

    • Neurons controlled the jellyfish movements! evolutionary fundamental

    • Moved with electrical impulses (action potentials)


  • Function of the nervous system is to produce movement and would need to evolve as animals traveled from the salt water environment to land

    • This factor led to the creation of cerebral spinal fluid (acts as this salty fluid)


  • Brain (cerebrum) and spinal cord are wrapped in a membrane called meninges to encapsulate the “salty water” & keep it in contact with the nervous system

    • Three Layers

      • Dura Mater (thick outer layer)

      • Arachnoid (Middle)

      • Pia Mater (inner)

  • Ventricular System

    • Cerebral spinal fluid (CSF) is made by the choroid plexus which pumps the fluid through ventricles

  • Meningitis and Meninges

    • The disease is associated with the inflammation of the meninges which can lead to infections in the nervous system



Subsystems of the Brain → Systems Neuroscience

  • Divisions of the Nervous System

    • Central Nervous System; these components are incased in bone

      • Brain

      • Spinal Cord

    • Peripheral Nervous System; perceives touch

      • Can be the neurons that are outside the bone, the ones on our fingertips

    • Different regions of the brain are associated with diff. cognitive and behavioral tasks



Circuits → Circuits & Systems Neuroscience

  • Circuits of neurons which are used for communication between them

    • Travel of information and connection of the brain between modules



Populations → Circuits Neuroscience

  • Neurons have different categories/morphologies

    • Sizes

    • Shapes

  • Branching patterns of different neurons exhibit diverse morphologies


  • Neurons can also be categorized by their release of neurotransmitters

    • ex. GABAergic neurons has the ability to release GABA neurotransmitters


  • Categorized by their efferent axonal target (Connectivity)

    • Where neurons send their axons to synapse to

    • Projections neurons send axons (far)

    • interneurons send their axons locally (close) 


  • By recording electrical activity of neurons will allow us to identify the type of neuron

    • The use of electrodes



Neurons → Circuits and Cellular/Molecular Neuroscience

  • Actually! Two types of cells in the nervous system

    • Glia and Neurons

  • Neurons: Will generate action potentials to allow for fast signaling

    • Allows for a fast sense and response



Compartments → Cellular/Molecular Neuroscience

  • A neuron can be divided into compartments

    • Dendrites (gets inputs)

    • Soma (cell body)

    • Axon (sends out the output)

    • Axon Terminals (send output in multiple directions)

      • Releases neurotransmitters


  • Synapses → What neurons use to send communication

    • Information transfer happens through here, little gaps

    • Neurons are connected through synapse junctions

      • the presynaptic neuron sends the information

      • the postsynaptic neurons receives the information

        • The type of neuron can different based on the particular synapse we’re looking at;

    • Neurons are connected in different ways, neurons is the basic unit of the nervous system


  • Neurotransmitters → How information between neurons is sent

    • Released through action potentials and will bind to the neurons dendrites receptors

    • Neurotransmitters can be sent to multiple neurons and received by receptors

      • Can also send different kinds of neurotransmitters



Molecular Level → Cellular/Molecular Neuroscience

  • Cells insides of the nervous system are covered in molecules which are necessary for cell functions

    • Different receptors and molecules to preform different functions