Biological Psychology

Monism

Theory that the mind and the body (or brain) are not distinct entities, but rather a single, physical substance

Dualism

theory that the mind (consciousness, thoughts) and the body (brain, physical matter) are two separate, distinct, and independent substances that interact with each other

Epigenetics

studies how environment and behavior (like stress, diet, or nurturing) change how genes work without altering the DNA sequence itself

Stress-diathesis model

suggests that mental disorders results from a combination of a pre-existing vulnerability (diathesis) and stressful life events

Reductionism

take a complex phenomenon and reduce it to its most basic component

Generalization

• “if this, then that”

• Explains how phenomenon works

Glial cells

Helper cells (assistants)

Neurons

• Brain cells

• building blocks of the bran and, therefore, consciousness

What makes the cell?

the cell wall

Rene Descartes

• Hydraulic model: proposed the body functions like a hydraulic system (fluids, pistons)

• Best known for his philosophy

• philosophy x biology = psychology

J. Muller

Doctrine of specific nerve energies

• Different systems, different types of electricity

L. Galvani

• Experiments with animals (especially frogs)

• Body works using electricity

P. Broca

• Clinical method: track the health of the client throughout their life (medical records)

• Broca’s area: the part of the brain that controls speech

• Localization of function: specific parts of the brain serve specific functions

Fritsch and Hitzig

Research with animals (dogs)

• Would open the skull to expose the brain to stimulate certain parts of the brain while the dog was awake

• Discovered motor cortex: further proved localization

W. Wundt

Started a lab to discover what it means to be “us”

when was the beginning of psychology?

1879

S. R. Cajal

• Artist/scientist

• took brain slices, slid them under a microscope after putting ink on them, and saw individual cells

• Discovered the neuron

• Drew beautiful pictures of what he saw

C. Sherrington

• SYNAPSES

• Realizes cells don’t physically touch (small gap between; discovered synapses_

J. Eccles

• CHEMICAL

• Realizes neurons communicate with chemicals not electricity

• discovered neurotransmitters

society for neuroscience

individuals get together and share research

The decade of the brain 1990-2000

Put aside taxpayer money for research on the brain

the BRAIN initiative

President Obama signed BRAIN initiative

• Brain Research through Advancing Innovative Technologies

Glial cells (CNS & PNS)

• Metabolic support

• protection

• insulation

• structural support (hold neurons in place)

• remove waste

• modulate neurotransmission

Astrocytes

(play goalie: keep certain things from crossing over from the blood to the brain; barrier)

• BBB: Blood Brain Barrier

• Structural support: “infrastructure”

• Phagocytosis (some)

• Control level of chemicals/ions outside the neuron

• Aid in the exchange of nutrients and waste

Microglia

• Very small

• phagocytosis

• Immune system functions

Phagocytosis

phagocytes engulf large particles by extending their plasma membrane around the target forming an internal vesicle, then digesting it

Schwann Cells

• only supports 1 axon

• form myelin

• only exist in the PNS

• help neuronal growth following damage

• guide axons to target neurons

• wraps itself around the neuron

Oligodendrocytes

• Supports numerous axons

• support neurons

• form myelin sheath

• Only exist in the CNS

multiple sclerosis

• Immune system attacks glial cells

• Neurons die as glial cells no longer protect them

Neurogenesis

creation of new neurons

lipid = …..

fat.

The cell wall

• semipermeable membrane: some things can get through it

• phospholipid bilayer

• contains numerous specialized proteins

phospholipid bilayer

• phospho heads: hydrophilic (love water, always want to face the water)

• lipid tails: hydrophobic (repel water)

outside the cell

extracellular fluid

inside the cell

cytoplasm

membrane proteins and functions

• receptors (sites of action for neurotransmitters)

• gated ion channels (allow for ions to move back and forth)

• pumps/transporters (move ions and molecules across biological membranes)

• structural, recognition, others

identify the parts of the neuron

1. Dendrites

2. soma

3. cell nucleus

4. axon hillock

5. myelin

6. axon

7. node of ranvier

8. axon terminals

dendrites

• receive signals from other neurons

• dendritic spines

• ligand-gated receptors: specialized proteins activated by chemicals

soma (or cell body)

• contains nucleus, other organelles

• protein synthesis for cellular growth and survival

• - receptors, enzymes, cell membrane

cell nucleus (inside soma)

• chromosomes: long strands of DNA

• genes: small portions of chromosomes, code for the production of specific proteins

axon hillock

• summation of all incoming signals: takes all the synaptic signals + summates them

• Once summated, signal is generated here and sent down the axon

myelin

protective layer formed by glial cells (Schwann)

axon

• carries signal to axon terminal

• also carries nutrient and waste

Node of ranvier

• gaps where there is no myelin

• axon contains voltage-gated (change in electricity on the axon) ion channels

axon terminals (terminal buttons)

• release neurotransmitters

inside the axon: axoplasmic transport

1. microtubules run down the axon

2. newly made proteins carried down the microtubules to axon terminal (anterograde transport, motor protein: kinesin)

3. at terminals, new proteins are released

4. waste carried back to the soma (retrograde transport, motor protein dynein)

anterograde transport

• biological process of moving materials—such as proteins, neurotransmitters, and cellular structures—outward from the center of a nerve cell (the

  cell bodyor soma) toward the tip of the cell (theaxon terminal). 

• “fast-delivery delivery service”

motor protein: kinesin

• acts as a microscopic delivery truck inside cells, including neurons (nerve cells)

• kinesin moves toward the microtubule plus end(outward from the cell center)

motor protein: dynein

• acts as a microscopic transport worker inside cells, particularly in brain neurons.

• moves toward the minus end (inward toward the cell center)

retrograde transport

• It is the process where materials are moved backward from the axon terminals (the end of the nerve branch) to the cell body (soma), which is the center of the neuron. 

• The “return shipping” service of a neuron

2 processes of neural communication

1. an electrical processes occurs inside the cell (the action potential)

2. a chemical process occurs between cells (ligands, neurotransmitters or hormones, or drugs)

resting membrane potential

compared to the outside of the cell the inside of the cell holds a charge of -70mv (millivolts)

• specialized protein pump

• uneven distribution of ions

• resting neuron has 70mv fewer than outside the cell

specialized protein: the Na+/K Pump

• For every two K+ ions pumped into the cell…

• three Na+ ions pumped out of the cell

• Uneven movement of + ions helps maintain RMP of -70mv

concentration force

• wants to balance amount of things

• greater amount moved to where there is a lesser amount

• is the natural tendency of molecules or ions to move from an area where they are highly crowded (high concentration) to an area where they are less crowded (low concentration).

electrostatic force

• electrical charge

• think of a magnet —> similar charges repel, opposites attract

• opposite electrical charges attract each other, and like charges repel each other, driving the movement of ions (charged particles) in and out of nerve cells.

depolarization

the process where a neuron (nerve cell) becomes activated, shifting its internal electrical charge from negative to positive, which triggers a nerve impulse (action potential). 

• if it reaches -65mv, it reaches threshold of excitation, causing more action

hyperpolarization

a change in a neuron's membrane potential that makes the inside of the cell more negatively charged compared to its normal resting state

the action potential (AP)

1. ligand binds to post-synaptic receptor on dendrite

2. ligand-gated Na+ channels open; Na+ influx

3. internal charge moves from -70mv to -65 mv (threshold of excitation)

4. voltage gated Na+ channels open

5. at +55mv, Na+ channels close/V-gated K+ channels open

6. K+ efflux (flowing out of a particular substance or particle); internal charge to -90mv (hyperpolarization)

7. at -90mv K+ channels close

8. V-gated Cl- channels open, Cl- efflux

9. Return to RMP (resting membrane potential) of -70mv

Vesicle & NT Release

• AP reaches terminal button

• voltage-gated Ca++ channels open, Ca++ influx

• Ca++ activates Calmodulin kinase KII

• CamKII phosphorylates synapsin

• Vesicles move toward terminal membrane (synapse)

• SNAP proteins line up

• Vesicle joins with membrane

• Neurotransmitter released in synapse (exocytosis)

neurotransmission

the process where nerve cells (neurons) send chemical messages to each other to communicate, allowing the brain to control thoughts, feelings, and behavior

ionotropic receptors

• 4-5 protein subunits (they mesh together)

• ion channel located in the protein receptor

• NT binds to receptor (ion channel opens, ions move either in our out of the cell)

• fast but rapid

metabotropic receptors

• Think metabolism

• single protein (but winds in and out of the cell wall, typically 7 times)

• metabolic process

• ion channel located distantly in cell wall (no ion channel here, close but far away)

• slower transmission (takes longer because of process outside the cell)

• slower but longer effects

kinases

responsible for opening distant ion channel

excitatory NT and receptor combination

• causing depolarization and AP in post-synaptic cell

• excitatory post-synaptic potential (aka EPSP)

excitatory post-synaptic potential (aka EPSP)

a temporary, positive change in a neuron's voltage that makes it more likely to fire an electrical impulse (action potential).

inhibitory NT and receptor combination

• causing hyperpolarization and no AP in post-synaptic cell

• inhibitory post-synaptic potential (aka IPSP)

inhibitory post-synaptic potential (aka IPSP)

a temporary reduction in a neuron's likelihood of firing an electrical signal (action potential).