PSYC 304 midterm 1 BRAIN BASICS

Describe how we have used, and continue to use, metaphors to descibe brain function. In what ways are these beneficial? In what ways are they limiting?

Galen: - humours, fluids govern diff aspects of our cognition and behaviour, animal spirits

L: reduces complex mental processes to the interaction of just four bodily fluids

Vesalius and Descartes: - hydraulics, body is a machine with fluids and pipes, driven by hydraulic pressure, soul tickles brain, soul->brain->mechanisms

L:

Galvani and du Bois-Reymond:

- brain as a battery, nerve signals are electrical impulses

L: don't look at the biochemical processes in the brain as well

- localization of function

- L: phrenology: shape of someone's head determines their characteristics which is a false theory

Schwann:

- cell theory: life is composed of cells, so study brain cells instead of as a whole

NOW: brain as a computer, or network of computers

Name two theories of neuron function. which one was shown to be predominantly correct?

Golgi vs Ramon y Cajal

Golgi: - brain is a mesh with all cells connected

Ryc: - cells have input and output, sense of directionality, not continuous bc they have a gap for chemical transmission

have a foundational understanding of basic brain facts. what aspect of human brain is most clearly, mechanistically related to our intelligence?

- size of brain does not equal to intelligence

- cells are not replaces

- neurons, glia, stem cells, blood vessels

- convoluted

- # of glia > # of neurons

intelligence = brain cell density = # of brain cells, sophistication of cellular connections

white vs gray matter

white matter : long-range myelinated axons, connections between neurons

grey matter: numerous cell bodies, unmyelinated axons

name and describe two general types of cells and describe some functional roles for each

neurons - communicate through axons, which generate action potential, which makes speed of communication very fast

glia - glue and support the system

name four types of glial cells and describe some functional roles for each

astrocytes:

- blood brain barrier - mediate nutritions into brain

- wrapped around synapse - maintain chemical environment

schwann cells:

- myelinate a single axon in PNS

oligodendrocyte:

- mylelinates several axons in CNS

microglia:

- covered in receptors

- swallows up bacteria in brain

explain what is meant by a tripartite synapse

conversation of 3 in the synapse:

- axon: releases neurotransmitters

- dendrite: has receptors

- astrocyte: has receptors and can release glia transmitters

Draw, label, and define the major features of a neuron AND TYPES

- single direction: dendrite => soma => axon => axon terminal

- input and output layer

- used for communication

types:

pyramidal - pyramid shaped and found in cortex

stellate - star-shaped and found under the cortex

purkinje - connected to thousands of neurons at once, found in the cerebellum

types 2:

projection neurons - long myelinated axons that go from one region in the brain to another, wire metaphor

interneurons: localized, unmyelinated, synchronize activity across many different neurons

describe the central dogma of molecular biology

DNA->mRNA>->protein

- protein is the basis of neuronal function

- transcription occurs when both activators are present and repressor is present

- expression of genes is determined by how tightly the histone is wrapped

name and describe the key function of some key cellular structures

RIBOSOMES:

- translate mrna to protein

- free ribosome = intracellular or free protein

ROUGH ER:

- protein is weaved into membrane

GOLGI APPARATUS:

- protein is packaged and sent to wherever needed

MITOCHONDRIA:

- oxygen + glucose = ATP

- makes energy for the cell

CELL MEMBRANE:

- phospholipid bilayer to keep things inside and outside cell

- you need membrane proteins to get across

cytoskeleton, axon, synapse and dendrites

cytoskeleton = internal structure of neuron, can grow or shrink

- main motive is to transport molecules

- kynesin and dyenin use atp to carry

synapse = site of neuronal communication = closer synapse is to an axon = stronger AP

- axosynaptic = axon ends on synapse and can modify the signal

dendrites = synapses are malleable = more malleability

identify three types of staining and the use for each

silver nitrate stain: tained only a subcomponent of cells, good for looking at structure of neuron

nissl stain - pigmented and binds to gray matter, looks at whole

fiber stain - white matter, staining insulating glia cells