Psych 30- midterm 1 terms

just terms from chapters 1-3

Descartes

* favored Mind-body dualism:
* Mind and brain are separate
* One can exist without the other

Luigi Galvani

* first discovered a role for electricity in Neural communication used by the nervous system

Neuron Doctrine

* discovered by Santiago Ramon y Cajal
* ==Cajal== believed that the nervous system comprised a vast array of independent, seperate nerve cells
* awarded nobel prize in 1906

Fritsch & Hitzig

* Identify localization of motor function in the cerebral cortex
* described how electrically stimulating the cortex of a rabbit and a dog produced movement on the opposite side of the body

Paul Broca

* identified localization of speech production
* concept of localization of function in the brain
* Brocas area: an area near the primary motor cortex in the frontal lobe that participates in speech production

Phineas gage

* suffered an accident, rod shot through frontal lobe of brain
* he survived but was a “changed man”
* Gages case illustrates the localization of higher-order cognitive function in the frontal lobe

Frontal Lobotomy

* A surgical procedure in which a large portion of the frontal lobe is separated form the rest of the brain

Golgi stain

* discovered by Camillo Golgi
* used to observe a small number detail structure of __single cell__ neurons

Nissl Stain

* helps identify clusters of __cell bodies__, the major bulk of the nerve cell, within a sample of tissue

Myelin stain

* a stain used to trace neural pathways

Horseradish peroxidase

* a stain used to trace axon pathways from their terminals to points of origin

Computerized tomography (CT)

* Studying structure and diagnosing structural damage
* use x-ray technology to produce high resolution images of the soft tissue like the brain
* cons: must justify additional exposure to x-rays for research participants
* cant distinguish between a living brain and a dead one (cant show activity levels in brain)

Positron emission tomography (PET)

* Studying the relative activity of nervous system structures


* imaging technique that provides information regarding the localization of brain activity
* measures brain activity based on the utilization of glucose or oxygen
* data from gamma rays resulting from the breakdown of the racer are recorded by detectors and fed to a computer
* pros: first technique to provide information about brain activity
* cons: exposure to radioactive tracer; less resolution than other methods

Magnetic resonance imaging (MRI)

* Studying structure in very fine detail
* uses magnetism and radio frequency waves
* pros: images have very high resolution
* cons: increasingly stronger magnets may affect behavior and safety

functional MRI (fMRI)

* Studying the activity of nervous system areas
* allows us to correlate brain activity with the presentation of a stimulus, the presence of an emotional state, or the performance of a particular task in living humans
* uses a series of images taken in a short period of time to analyze brain activity

Diffusion tensor imaging (DTI)

* Studying fiber pathways in the nervous system
* uses the MRI technology to trace fiber pathways in the brain by tracking the flow of water in the nervous system

Electroencephalogram (EEG)

* first recording made by Hans Berger in 1924
* scalp electrodes provide information about the activity of large populations of neurons
* used to study states of consciousness and seizures

event-related potentials (ERP)

* series of EEG responses to environmental stimuli
* useful in studying perception

Magentoencephalography (MEG)

* allows researchers to record the brains magnetic activity
* brains magnetic output is assessed
* skull is transparent to magnetism, not electricity, making MEG superior to EEG

Lesion

* injury to neural tissue and can be either naturally occurring or deliberately produced
* results can be used to determine the function of an area
* can be naturally occurring due to stroke or other brain damage
* artificially produced by heating the tips of surgically implanted electrodes or applying chemicals that kill cell bodies\\temporarily produce by cooling an area of the brain

Ablation

* surgical removal of tissue

stimulation

* discover the function of an area
* applied during neurosurgery
* through surgically implanted electrodes

knockout genes

* a gene used to replace a normal gene that does not produce the protein produced of the normal gene
* ex: researchers developed mice that demonstrate autistic-like behaviors by knocking out the genes for the enzymes monoamine oxidase A and A/B

Repeated transcranial magnetic stimulation (rTMS)

* consists of magnetic pulses delivered through a single coil of wire encased in plastic that is placed on scalp
* shown promise in the treatment of motor diseases and depression

optogenetics

* use of molecules genetically inserted into specific neurons in the brain, which then allows neural function to be modified by light
* light can be used to turn living neurons on and off

Phrenology

* Gall and Spurzheim (1758-1828)
* correlation of bumps on the skill with personal traits, was misguided in most respects.

synapse

* is the chemical connection between a neuron and another cell (usually \n another neuron).

Dualism

* mind and brain are separate
* one can exist without the other

monism

* mind and body are single substance
* mentalistic monism (all mind)
* materialistic monism (all physical)

cytoplasm

* the fluid inside a cell; also known as intracellular fluid

cell membrane

* double layer of phospholipids separates the intracellular an extracellular fluids
* protein ion channels allow the movement of molecules across the membrane

nucleus

DNA, where genetic material is housed

Ribosomes

* translating messages that DNA is sending through RNA and translating it into proteins

Mitochondria

* generate most of the chemical energy needed to power the cell's biochemical reactions.
* produces ATP

Microtubules

* provide transport
* not in dendrite, only in axon
* transporting that packaged material from the soma down the axon to the terminal ending

soma

main mass of a neuron, containing the nucleus and many organelles

dendrite

* the branch of a neuron that generally receives information from other neurons

axon

* the branch of a neuron usually responsible for carrying signals to other neurons
* transmit action potentials
* insulated by myelin

neurotransmitters

* a chemical messenger that communicates across a synapse and is released from the axon terminal and cross the synaptic gap
* synthesis and storagr in presynaptic neuron
* released by presynaptic axon terminal
* produces response in postsynaptic cell
* mimics response produced by release of neurotransmitter from the presynaptic neuron

axon hillock

* action potentials originate here
* the cone-shaped segment of axon located at the junction of the axon and cell body that is specialized for the generation of action potentials

Neurotransmitter deactivation

* Neurochemicals released into the synaptic gap must be deactivated before additional signals are sent by the presynaptic neuron.
* (a) diffusion away from the synapse
* reuptake: the transmitter brought back into the terminals
* inactivation: enzymes break down the transmitter in the cleft

Myelin

* secreted by glial cells, is a fatty tissue that surrounds axons, providing electrical insulation and support
* CNS: oligodendrocytes
* PNS: Schwann cells

terminal button (ending)

* Small knobs at the end of axons that secrete chemicals called neurotransmitters

sodium-potassium pump

* maintains ions differences by expelling 3 Na+ for every 2 K+ it brings in, causing less + (and more negativity) inside

tau (protein)

* connects adjacent microtubules and golds them in place
* in alzheimers disease, tau levels become elevated

Membrane potential

* gradient of electrical potential energy across a cell membrane
* always expressed as the potential inside the cell relative to the outside
* V= vin-vout

Na+

* sodium
* is attracted to the -70 mV INSIDE the neuron

K+

* potassium
* wants to go OUT of neuron

Cl-

* chloride ions
* outside membrane
* carrying a negative charge and inhibits action potential generation

A-

* Anions
* inside the membrane

Ca++

* calcium
* outside of the cell

voltage dependent ion channels

* activated by changes in voltage gradient across plasma membrane

NT-depdendent ion channels

* **known as ionotropic receptors, are responsible for fast synaptic transmission.**
* **they decode chemical signals into electrical responses,**
* **thereby transmitting information from one neuron to another**

membrane permeability

* the neuron has a selectively-permeable membrane
* water and gases pass freely through
* other substances are barred from entry
* others pass through protein channels in the membrane under certain circumstances

depolarization

* change in the membrane permeability towards 0mV (contraction, sodium gates open, more positive)
* sodium flows in - potential from -70mV towards positive charge

hyperpolarization

* polarization more negative than the resting potential
* potassium continues to flow out of cell - leaving it more negative charge from -70mV to -90mV

threshold

* stimulus required for opening of sodium gates, followed by opening of potassium gates; due to mechanical, chemical gates charge

saltatory conduction

* Action potentials jump from one node of Ranvier to another, in a very rapid form of \n transmission

graded potential

* stimulus causes gated ion channel to open

postsynaptic potentials

* small, local, graded potentials that can last 5-10 msec.

Excitatory postsynaptic potentials (EPSPs)

* produce slight depolarizations
* open sodium channels

inhibitory postsynaptic potentials (IPSPs)

* produce slight hyperpolarization’s
* open either chloride or potassium channels

Ionotropic

* A receptor protein in the postsynaptic membrane in which the recognition site is located on the same structure as the ion channel.
* opens post- synaptic ion channels, changing the potential
* have recognition sites located on the ion channel

metabotropic receptors

* A recognition site extends into the extracellular fluid, and a special protein called a G protein is located on the receptor’s intracellular side
* G proteins can open nearby ion channels or activate second messengers

all- or--none

* An action potential either occurs or does not occur

rate law

* Due to the relative refractory period, the neuron’s firing rate is \n proportional to stimulus intensity (the code for intensity in the axon)

Refractory period

* limit a cells rate of firing

Propagation of Action potentials

* Action potentials follow the all-or-none law, resulting in full depolarization and hyperpolarization, or none at all.
* As they travel down the axon, action potentials depolarize the membrane beyond the threshold, creating a nondecremental action potential that maintains its strength - it's an all-or-none phenomenon.
* The amplitude of an action potential remains constant and does not vary with the strength of the initial stimuli

Glial cells

* non-neural cells that provide a number of supporting functions to the nervous system
* found in peripheral nervous system
* make up 90% of brain volume

Blood-brain-barrier

* an impediment to the transfer of molecules from the circulation into the brain formed by the astrocytes
* the barrier between the blood and the extracellular fluid of the brain

central nervous system

* comprised of the brain and spinal cord
* spinal cord is a conduit for information to and from brain

Planes of dissection (sections)

* coronal (transverse)
* divides nervous system front to back
* Sagittal
* Parallel to midline
* Midsagittal section
* dvides the brain into two realtively equal halves
* horizontal
* (axial, )
* divides brain from top to bottom

Meninges

* layers of membranes that cover the central nervous system (CNS) and the peripheral nerves
* Dura mater, arachnoid, Pia mater

Ventricle

* one of four hollow spaces within the brain that contain cerebrospinal fluid (CSF)
* the brain venticles are an access point for drug studies
* the brain ventricles can expand when brain cells are lost (as in alcoholism or certain diseases)

Cerebrospinal fluid (CSF)

* The brain floats in a pool of this which reduces its net weight from 1400g→80g
* contained within four brain ventricles
* produced by the __choroid plexus__ of each ventricle

exocytosis

* the process in which vesicles fuse with the membrane of the axon terminal and release neurochemicals into the synaptic gap.
* ca2+ enters the cell
* vesicles fuse with the axon terminal membrane
* neurochemicals are released
* vesicles are returned to the terminal interior and refilled

Autoreceptors

* sense the amount of transmitter in the cleft and cause the presynaptic neuron to reduce excessive output

Electrical forces

* charged molecules will be attracted to areas of opposite charge and repelled by areas of like charge

diffusion forces

* Molecules will move from areas of high concentration to areas of low concentration

Action potential (AP)

* this occurs when a cell is depolarized to threshold
* the opening of sodium channels and potassium channels in the neural membrane accounts for the rise and fall
* Na+= IN
* K+= OUT
* refractory periods limits a cells rate of firing

Multiple sclerosis

* disease in which myelin is destroyed, reducing conduction speed.

Axo-axonic synapse

* connects the axons of two different neurons

Axo-somatic synapse

* synaptic connections between axon terminals of 1 neuron and soma (cell body) of others

Axo-dendritic synapse

* Synapse connections between axon terminals of 1 neuron and dendrites of others

dendro-dendritic synapse

* connects the dendrites of two different neurons

Neuraxis

* imaginary line drawn through the spinal cord up to the front of the brain

Anterior (rostral)

* toward the head

Posterior (caudal)

toward the tail

ventral (inferior)

toward the “belly”

dorsal (superior)

toward the back (top of head)

coronal section (frontal sections)

* divides nervous system front to back, parallel to face

Horizontal section (transverse) (axial)

* an anatomical section that divides the brain from top to bottom

sagittal section

* an anatomical section that is parallel to the midline

Afferent neurons (sensory)

* transmit information about the environment to the nervous system ( MOVING INSIDE)

Efferent nuerons (motor)

* transmit commands from the central nervous system to muscles and glands (MOVING OUT)

peripheral nervous system (PNS)

* the nerves exiting the brain and spinal cord that serve sensory and motor functions for the rest of the body

Hindbrain (rhombencephalon)

* most caudal divisions of the brain, including the medulla, pons and cerebellum.

Midbrain (mesecephalon)

* division of the brain lying between the hindbrain and the forebrain, including the superior and inferior colliculi, periaqueductal gray, red nucleus, and substantia nigra.

Forebrain (Prosencephalon)

* division of the brain containing the diencephalon and telencephalon

two parts of the forebrain (prosencephalon) called?

* telencephalon
* cerebral cortex, hippocampus, amygdala, basal ganglia
* diencephalon
* thalamus hypothalamus