PSY 209 EXAM 1

biological psychology

a branch of psychology concerned with the links between biology and behavior

what are 5 major perspectives to explore the biology of behavior?

1. Describing behavior
2. Studying the evolution of behavior
3. Observing the development of behavior and its biological characteristics over the life span
4. Studying the biological mechanisms of behavior
5. Studying applications of behavioral neuroscience

What are the 3 main approaches tp the study of brain and behavior?

1. Somatic intervention
2. Behavioral intervention
3. Correlation
Each approach enriches and informs the others

somatic intervention

an approach to finding relations between body variables and behavioral variables that involves manipulating body structure or function and looking for resultant changes in behavior
Ex: mild electric shock to one part of brain → patient laugh

behavioral intervention

an approach to finding relations between body variables and behavioral variables that involves intervening in the behavior of an organism and looking for resultant changes in body structure or function
Ex: Putting two adults of opposite sex together may lead to increased secretion of certain hormones

Correlation

A measure of the extent to which two factors vary together

confounding variable

a factor other than the independent variable that might produce an effect in an experiment

Neuroplasticity

the ability of the nervous system to change in response to experience or the environment

What types of variables are included in experiment design?

Independent (controlled by experimenter), dependent, confounding

What are the parts of the central nervous system?

brain and spinal cord

How is the brain protected?

The brain is protected by bone, meninges, cerebrospinal fluid, and the blood-brain barrier

What are the parts of the peripheral nervous system?

autonomic nervous system & somatic nervous system

autonomic nervous system

the part of the nervous system responsible for indirect bodily functions such as breathing

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles

Gyri (gyrus)

Large folds of tissue covering the surface of the cerebrum

Sulci (sulcus)

~shallow grooves separating the gyri
~ Divides the cerebral hemispheres into lobes

Lobes of the cerebrum

* frontal (movement and high-level cognition)
* parietal (receive sensory information from body and spatial cognition)
* temporal (auditory information)
* - occipital (receive and process information from eyes)

basal ganglia

a set of subcortical structures that directs intentional movements

caudate nucleus

One of the basal ganglia- it has a long extension or tail

globus pallidus

component of the basal ganglia that connects to the thalamus which relays information to the motor areas and the prefrontal cortex

Putamen

one of the basal ganglia

limbic system

neural system (including the hippocampus. associated with emotions and drives.)

Amygdala

A limbic system structure involved in memory and emotion

Diencephalon

thalamus

Thalamus

the brain's sensory switchboard- it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

Hypothalamus

A neural structure lying below the thalamus- it directs several maintenance activities (eating, drinking)

midbrain (mesencephalon)

part of the brainstem that connects the brainstem to the cerebellum- controls sensory processes

colliculi

two structures in the midbrain involved in sensorimotor reflexes- the superior colliculus receives visual sensory input- and the inferior colliculus receives auditory sensory input

Hindbrain

medulla

Medulla

the base of the brainstem- controls heartbeat and breathing

Cerebellum

the "little brain" at the rear of the brainstem- functions include processing sensory input and coordinating movement output and balance

Pons

A brain structure that relays information from the cerebellum to the rest of the brain

What different techniques can be used to visualize neurons?

immunocytochemistry, immunohistochemistry, DAPI, Nissl, In Situ, Ca+

DAPI stain

a fluorescent stain that binds strongly to DNA in a cell
- how many and where are cells located

Nissl stain

fills out the cell bodies of the neuron dye bonds to any RNA in the cell

* used to measure size and density of cells

Immunocytochemistry

uses antibodies attached to a dye to identify cellular components such as receptors

Immunohistochemistry

localizing antigens or proteins in tissues using labeled (colored or fluorescent) antibodies
-uses sections of tissue

In Situ Hybridization

A technique using nucleic acid hybridization with a labeled probe to detect the location of a specific mRNA in an intact organism
- results in clear expression of cell type

calcium imaging

A method of measuring receptor activity by using fluorescence to measure the concentration of calcium inside the receptor. This technique has been used to measure the activation of olfactory receptor neurons.

How are neurons classified?

structurally and functionally

Parts of a neuron

cell body, axon , dendrites

cell body (soma)

contains the nucleus and other parts of the cell needed to sustain its life

Axon

A threadlike extension of a neuron that carries nerve impulses away from the cell body.

Dendrites

Branchlike parts of a neuron that are specialized to receive information.

Anterograde vs retrograde transport

anterograde: moves material toward axon terminals
retrograde: moves used materials back to cell body for recycling

Neurotransmitters in autonomic nervous system

sympathetic nervous system: norepinephrine (accelerates activity)
parasympathetic nervous system: acetylcholine (slows down activity)

enteric nervous system

key role in maintaining fluid and nutrient balances in the body (controls functioning of gut)

Camilo Golgi

Invented Golgi stain- reticular theory

Reticular Theory

nerves communicate through a continuous nerve network

Santiago Ramon y Cajal

Cajal proposed that although neurons come very close to one another (i.e. neuron doctrine)

Neuron Doctrine

cells of the brain are independent from one another structurally

Synapse

Gap between neurons

Which type of synapse is most common in the nervous system?

chemical synapse

electrical synapse

Occurs when large ions alone freely pass from one neuron to the next
-very quick and bidirectional
-regulation of slow-wave sleep

pre-synaptic neuron

a neuron that delivers a signal to a synapse
(releases neurotransmitter)

post-synaptic neuron

the neuron on the receiving end of the synapse
(receives and responds to neurotransmitter)

Components of a synapse

presynaptic membrane, synaptic cleft, postsynaptic membrane

synaptic cleft

The narrow gap that separates the presynaptic neuron from the postsynaptic cell, synaptic vesicles

synaptic vesicles

a small, spherical structure that contains molecules of neurotransmitter

presynaptic membrane

the specialized membrane of the axon terminal of the neuron that transmits information by releasing neurotransmitter

postsynaptic membrane

the specialized membrane on the surface of the cell that receives information by responding to neurotransmitter from a presynaptic neuron

Myelin

a fatty substance that helps insulate neurons and speeds the transmission of nerve impulses

ways synapses can connect

* axo-dendritic
* axo-somatic
* axo-axonic
* dendro-dendritic

Transmission in the CNS

Not all transmission in the CNS occurs neuron-to-neuron
-volume transmission(slow)

Key differences between chemical and volume transmission

chemical (synaptic) transmission:

* high speed
* high energy cost
* chemical and electrical signals
* quick temporal dynamics

volume transmission:

* low speed
* low energy cost
* chemical and electrical signals
* slow temporal dynamics

GABA and schizophrenia

loss of inhibitory GABA --\> causes increased activity of dopamine systems (excess dopamine \= schizophrenia)
Test this with DAPI stain (quantify GABA cells)

What is the resting membrane potential?

Difference in electrical charge across the membrane at rest
~65 mV

How do we measure resting membrane potential?

inserting a fine microelectrode inside a neuron and using a voltmeter to compare the cell's interior with the extracellular fluid surrounding it

How do ions contribute to resting potential?

positive potassium channels and positive sodium ion channels move in and out to maintain a balanced system

Diffusion

the spontaneous spread of molecules of one substance among molecules of another substance until a uniform concentration is achieved

electrostatic force

The force between electrically charged objects (like charges repel and opposite charges attract each other).

Na+ pump as bouncer

the cell is Harp's and Jose is only allowing two K+ for ever Na+ that leave, he maintains and equilibrium

If no other activity occurs,

what is the result of the Na+ pump inside and outside the cell?

\

What is action potential?

a neural impulse- a brief electrical charge that travels down an axon

What happens before action potential?

the cell membrane of the neuron allows certain ions to pass through while preventing or restricting other ions from moving
-sodium and potassium ions cannot easily pass through the membrane
-Chloride ions are able to freely cross the membrane

What happens during action potential?

there's a sudden reversal of charge, carrying a message down the axis (depolarization)

What happens after action potential?

refractory period- the inside of the cell membrane returns to very negative charge and K+ enters the membrane again

How are neurons like batteries?

they separate electrical charges, creating energy that can be tapped into at any time

Why do we need appropriate amounts of ions in our bodies?

We need appropriate amounts of ions in our bodies because without them we could never get action potential (excess cations= very positive, constant action potential) (excess anions= very negative, will never reach action potential)

Depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive

Hyperpolarization

The movement of the membrane potential of a cell away from rest potential in a more negative direction.

Where are sodium and potassium ions relative to cell membrane during depolarization?

sodium and potassium rushes into the cell

Where are sodium and potassium ions relative to cell membrane during hyperpolarization?

sodium and potassium is pushed out and chloride rushes in

saltatory conduction

Rapid transmission of a nerve impulse along an axon, resulting from the action potential jumping from one node of Ranvier to another, skipping the myelin-sheathed regions of membrane

What are the nodes of Ranvier?

gaps in the myelin sheath

Where are nodes of Ranvier located?

between myelins

How does conduction differ between myelinated and unmyelinated axons?

Moves faster on myelinated axons

What is the most common excitatory neurotransmitter?

Glutamate

What happens when glutamate binds to post-synaptic cell?

glutamatergic transmission uses particular receptors which when activated leads to NA+ entering the post-synaptic cleft

What is the most common inhibitory neurotransmitter?

GABA

What happens when GABA binds to the post-synaptic cell?

GABAergic transmission uses particular receptors which when activated lead to Cl- entering the post-synaptic cell

What is EPSP?

excitatory post synaptic potential
- pre-synaptic cells releases glutamate into synaptic cleft
- Na+ channels open in response to glutamate binding
- more Na+ outside cell than inside

What is IPSP?

inhibitory post synaptic potential
- presynaptic cell releases GABA into synaptic cleft
- GABA binds to receptor and immediately opens Cl- channel
- Cl- enters and cell is hyperpolarized

What is the axon hillock?

This is a part of the neuron, between the cell body and the axon, that controls traffic down the axon through summation of excitatory and inhibitory postsynaptic potentials.

temporal summation

Summation by a postsynaptic cell of input (EPSPs or IPSPs) from a single source over time.

spatial summation

Integration by a postsynaptic neuron of inputs (EPSPs and IPSPs) from multiple sources.

How is summation involved in action potential?

if the ESPS depolarizes the postsynaptic neuron enough, it can produce an action potential

What is an ionotropic receptor?

ion channels

What is a metabotropic receptor?

a second messenger that activates other channels downstream with G-protein activation

What is a neurotransmitter?

chemical messenger
criteria:
-exists in presynaptic terminals
-synthesized in presynaptic cells
-released when action potential reaches axon terminals
-receptors on postsynaptic membrane
-produces changes in post-synaptic potential
-blocking release prevents changes in postsynaptic cell