Sam's NSCI 175 Exam Review - Units 1 and 2

Reductionist Approach

Breaking apart a complex phenomenon into fundamental parts to make analysis easier

Molecular (Level of Analysis)

The Nervous System is composed of a multitude of molecules; Studies molecules associated with the nervous system e.g. Dopamine (a neurotransmitter), Glucose, Sodium Ions

Cellular (Level of Analysis)

How all present molecules work together to give neurons their special properties

Systems (Level of Analysis)

Having a group of neurons that work together/share a common function e.g. visual and motor system (sensory systems)

Behavioral (Level of Analysis)

How neural systems work together to produce integrated behaviors → things that we can observe e.g. movement

Cognitive (Level of Analysis)

Understand the neural mechanisms that are responsible for higher levels of human mental activity e.g. attention, consciousness, learning

Difference between molecular and cellular level of analysis

Is it a neuron or is it a part of a neuron

Four Essential Steps in Scientific Process

Observation, Replication, Interpretation, Verification

Observation

Carefully watching experiments and making sense of results (typical scientific method)

Replication

Seeing if the original result happened by chance by repeating the original proces

Interpretation

After finding that it didn’t happen by chance, you find meaning by using what’s already published

Verification

Other scientists in different locations under potentially different circumstances are able to replicate your experiment. This is where scientific fact is established

Explain why the progress of science is often slow

Depends on how the controls are set

Within Subject Experiment

the control group is the same set of subjects tested before an alteration

Between Subject Experiments

The experimental control is compared to a separate control group that has been treated identically except for experimental manipulation

Independent vs Dependent Variables

Manipulated vs Measured

Why do we use animals in neuroscience

We use animals to mdoel human brains because they are very similar

Animal Rights

Terminate the use of animals for human purposes including research because they have the same moral and legal rights as humans

Animal Welfare

Aims to ensure that animals are treated well through “institutional animal care and use committees” which are federally required

Which animal model would be best suited for a cognitive neuroscience experiment?

A primate would be best suited because they are the closest to human subjects

Reticular Theory (Golgi)

Neurons are continuously connected and information spreads through the neuron similar to a cell - nerve net as the basic unit of the CNS

Neuron Doctrine (Cajal)

Neurons communicate through direct contact - each neuron is an individual cell

How did Golgi and Cajal get their data?

Golgi Stains - staining neurons within brain tissue

1

Dendrites - Neurite specialized to receive inputs from other neurons

2

Soma - region of the neuron that contains the nuclear and other organelles

3

Nucleus - spherical center of the neuron

4

Nodes of Ranvier/Myelin Sheaths - wrap around axons and insulate them to speed up propagation of action potentials

5

Axon Terminal - End region of the axon and usual site of synaptic contact with another cell

Axon/Presynaptic Terminal

Neurite specialized to conduct nerve impluses aka action potentials. Synaptic vesicles are present and neurotransmitters are released

Synpase

the location in which neuronal communication happens

How are neurons specialized for communication?

Synaptic clefts bind to receptors; postsynaptic dendrites receive information from contact with axon terminals; many terminals but only 1 axon

How can neurons be classified?

Structure, Connections, and Gene Expression (what neurotransmitter)

3 Types of Neuron Structure - Depend on number of Neurites

(Sensory)Unipolar, (Motor) Bipolar, (Inter) Multipolar

Sensory Neurons

Have connections with sensory surfaces allowing them to convert external stimuli into internal electric impulses

Motor Neurons

Connect with muscles to transmit the synpase

Types of Glial Cells

Schwann Cell, Oligodendrocyte, Microglia, Ependymal Cells, Astrocyte

Schwann Cell

Found in the PNS, they myelinate singular segments

Oligodendrocyte

Myelinate multiple segments in the CNS

Microglial Cell

Triggers inflammation and removes debris left by dying neurons - can change their morphology

Ependymal Cell

Direct cell migration during development

Astrocyte - The most numerous glia

Fill up the spaces between neurons and are associated with neurite growth - regulate chemical content

Glia outnumber neurons in the brain, but neurons are the focus why?

Neither can function without the other and we don’t know which is more common

Nissl Staining

Distinguishing Neurons and Glia

Golgi Staining

Stains neurons entirely, but is selective for some neurons

Immunohistochemistry

Stain the protein of a receptor using an antibody

In Situ Hybridization

Targets mRNA with radioactive coloring

Neurons vs Glia

Neurons are responsible for unique functions, like sensing/communicating/commanding and Glia contribute to brain function by insulating/supporting/nourishing