NEUR200-UMD-First Exam

EPSP (excitatory postsynaptic potential)

- depolarizing graded potential in postsynaptic neuron in response to activation of excitatory synapse
- caused by entrance of Na+ ions into the cell
- make cell more likely to fire an action potential.

IPSP (inhibitory postsynaptic potential)

- synaptic potential that makes a postsynaptic neuron less likely to generate an action potential
- temporary graded hyper-polarization of postsynaptic membrane.
- increases the negative charge within the neuron
- caused by exit of K+ ions/entrance of Cl- ions

Temporal summation

- "nagging"
- repeated stimuli within a breed time have a cumulative effect.
- when combination of excitation exceeds the threshold, an action potential is produced despite decaying over time.

Spatial Summation

- "voting"
- Synaptic input from different locations combine their effects on a neuron
- importance of timing

spontaneous firing rate

- a periodic production of action potentials even without synaptic input (absence of a task or stimulation)
- important for perception (perception is dependent on amplitude and phase of a spontaneous activity)

synaptic delay

- the brief delay between the arrival of an action potential at the axon terminal and the creation of a postsynaptic potential
- Sherrington observed conduction was never more than 15m/s

Graded Potential

- may be either excitatory (depolarization) or Inhibitory (Hyper polarization)

The EPSP will ________ the frequency of action potentials whereas IPSP will _____ it

increase, decrease

Neural Synchronization

- brain waves from different regions will synchronize/communicate.
- can give rise to oscillations

Golgi method

silver staining technique to stain limited number of nerve cells

Cajal

nerve cells remain separated

cell doctrine

1. all living things are composed of cells and cell products
2. a single cell is the smallest unit that exhibits all the characteristics of life
3. all cells come only from preexisting cells

structure of cell
1. membrane
2. nucleus
3. mitochondria

1. separated inside from outside
2. chromosomes
3. metabolism (energy)

Neuron structure

- dendrites
- soma
- axon
- presynaptic terminals

Schwann cell

- glial cell that forms myelin in the peripheral nervous system.

node of Ranvier

- A gap between successive segments of the myelin sheath where the axon membrane is exposed.

axon

A single extension from the nerve cell that carries action potentials from the cell body to other neurons.

dendrite

One of the extensions of the cell body through which synaptic inputs are received.
- fibers with synaptic receptors that receive info from other neurons

cell body Also called soma.

The region of a neuron that is defined by the presence of the cell nucleus.
- most of the metabolism of neuron occurs here
- they may also have synapses

presynaptic vs postsynaptic

- Referring to the region of a synapse that releases neurotransmitter.
- Referring to the region of a synapse that receives and responds to neurotransmitter.

multipolar neuron

- many dendrites, one axon

Bipolar Neuron

A nerve cell that has a single dendrite at one end and a single axon at the other end.

Unipolar Neuron

Also called monopolar neuron. A nerve cell with a single branch that leaves the cell body and then extends in two directions; one end is the receptive pole, the other end the output zone.

Motor Neurons

- Also called motoneuron. A nerve cell that transmits motor messages, stimulating a muscle or gland.
- its soma is in the spinal cord, conducts impulses along its axon to a muscle.

Sensory Neurons

- A neuron thatis directly affected by changes in the environment, such as light, odor, or touch.
- soma located in the trunk

efferent vs afferent neurons

Efferent: "exit "motor neurons that transmit impulses AWAY from CNS
Afferent: "brings info inside" sensory neurons that transfer impulses TOWARDS the CNS

Nucleus is where

the genes for making proteins are stored

Neuron as a factory

gene info is transcribed--> RNA --> gets in contact with ribosomes --> code gets translated into --> amino acid chains --> form proteins

Glia is the glue of the brain by

- providing supporting cells to give firmness and structure.
- smaller but more numerous than neurons

Macroglias vs Microglias

- Astrocytes: A star-shaped glial cell with numerous processes (extensions) that run in all directions.
- Oligodendrocytes: A type of glial Behavioral Neuroscience cell that forms myelin in the central (Schwann cells in the PNS)
vs.
- Microglias: remove cellular debris from injured or dead cells.
, injury/infection

Blood-brain barrier

The mechanisms that make the movement of substances from blood vessels into brain cells more difficult than exchanges in other body organs.

The action potential only propagates in one direction because in the opposite direction the axon is:

Hyperpolarized due to potassium exiting the neuron.

The presynaptic neuron is ...

The neuron that delivers transmission.

Stimulants used to treat ADHD ...

Increase dopamine in the synapse by inhibiting the reuptake of dopamine

Von Economo or spindle neurons are ... neurons characterized by one axon and a single dendrite. They are suggested to be related to ...

Bipolar / social behaviors

true or false, At the nodes of Ranvier, potassium ions enter the axon to regenerate the action potential

False

The presynaptic terminals are in the ...

axon

T/F? Sherrington is known for inventing a technique to stain a limited number of nerve cells.

False

The membrane of the neuron is:

What separates the inside from the outside

Monoamines include ...

Serotonin, dopamine and noradrenaline

What is Ramon y Cajal known for?

Proposed that there are tiny gaps between nerve cells (neurons)

T/F? The ribosome is the part of the cell where the genetic code is read and translated into a specific amino acid chain, which forms the protein.

true

What does the myelin sheath of an axon accomplish?

It enables action potentials to propagate more rapidly.

T/F? COMT is an important protein that breaks down dopamine. Different levels of COMT can influence behaviors such as impulsivity and attention.

True

T/F? Efferent neurons are also called motor neurons

True

Approximately, the human brain may have around

100B

one way of stating the all-or-none law?

All stimuli that exceed the threshold produce equivalent responses in the axon of a neuron.

T/F? Intrinsic neurons bring information in (from the sensory systems to the central nervous system).

False

Under what conditions does an axon produce an action potential?

Whenever the membrane's potential reaches the threshold (~-55 mV)

The mesocortical pathway goes from ...

VTA--> PFC

The mesolimbicl pathway goes from ...

VTA--> NAc

The nigrstriatal pathway goes from ...

SN--> BGs

What is Golgi known for?

Created the silver staining technique to stain a limited number of nerve cells (neurons)

Suppose a neuron has a resting potential of -70mV. If the potential goes to -50mV, the change would be a ...

depolarization

Monopolar neurons ...

Have an axon that branches in two directions (input zone and output zone).

The ... pathway is known as the reward pathway, often studied in relation to substance use disorders.

mesolimbic

charcot-Marie-Tooth disease is a hereditary motor disorder that affects ...

Schwann cells

T/F? The presynaptic terminals, in the dendrites, is the part of the neuron where the neurotransmitters are released.

False

The blood-brain barrier is a system whose main mechanism includes specialized ... that help regulate the substances inside and outside the brain

Endothelial cells

Brain networks are ...

Groups of brain areas whose activity can synchronize to participate in a cognitive or psychological function.

Action potentials mainly occur in ...

axon

When the neuron's membrane is at rest, sodium ions are more concentrated ...

Outside

T/F? In ionotropic receptors, the effects are faster because a second messenger communicates with many areas inside the cell

false

functions of the glia is ...

Supply oxygen and nutrients.uRemove dead neurons.uDestroy pathogens.uForm myelin.uInsulate one neuron from the other.uGuide the migration of neurons during development.

Hyperpolarization of the membrane can happen when ...

Potassium ions exit the neuron or chloride ions enter the neuron

A multipolar neuron has...

One axon and many dendrites.

T/F? Astrocytes are glial cells that serve several functions, for example, they contribute the myelin sheath to the axon in the CNS

False

... triggers synaptic vesicle exocytosis in neurons.

Ca+2

T/F? The action potential only propagates in the direction of the dendrites.

False

Exocytosis is the process by which ...

The neurotransmitters in the vesicle are released to the exterior through the fusion of the vesicle with the membrane

T/F? Sodium and potassium channels are located in areas of the axon where myelin is present

False

Polarization is when

there's an electrical gradient (difference electrical charge between inside and outside of neuron).

How are those different charges (between the outside and the inside) maintained?

1. Sodium-potassium pump, protein that allows 3 sodium ions out and 2 potassiumions in.
2. The attraction between positive and negative charges creates the energy we need for the action potential (bow and arrow) àElectrical gradientuResting potential prepares the neuron to respond rapidly

At the peak of the AP, sodium channels ____ and because potassium channels are still open so _______, polarization occurs and the membrane returns to its resting potential.

close, (potassium ions exit the cell)

Action potentiall is when a Stimulation reaches the threshold leads to a massive depolarization of the neuron: sodium channels ____ and allow ____

open, sodium inside the membrane

why is it that during refractory period, the neuron resists the production of other APs.

1. Sodium channels are close
2. Potassium exit the cell.

the main synthesizer of Serotonin

Main synthesizer: Raphe nuclei.

Norepinephrine main synthesizes are:

Main synthesizer in the brain: Locus Coeruleus. In the PNS: adrenal cortex.

Norepinephrine and dopamine correlate

positively

dopamine and serotonin correlate

negatively

Glutamate is associated with excitotoxicity, a phenomenon in which

neural injury, such as a stroke or trauma, provokes an excessive release of glutamate that overexcites neurons, eventually killing them.

GABA receptors

Inhibitory postsynaptic potentials.
Influx of Cl-
drugs= benzodiapines

Acetylcholine

A neurotransmitter that enables learning/attention and memory (Alzheimer's) and also triggers muscle contraction
- nucleus basalts of myenert

Glutamate (neurotransmitter)

AMPA and NMDA
- psychosis and excitotoxicity

Norepinephrine

alpha and beta receptors
- associated with mood, energy, arousal

efferent vs afferent neurons

Efferent: "exit "motor neurons that transmit impulses AWAY from CNS
Afferent: sensory neurons that transfer impulses TOWARDS the CNS

efferent vs afferent neurons

Efferent: motor neurons that transmit impulses AWAY from CNS
Afferent: sensory neurons that transfer impulses TOWARDS the CNS