Intro to Neuroscience Exam 1

Neuraxis

Imaginary line drawn through the center of the length of the central nervous system

Ipsilateral

Structures on the same side of the body

What are groups of neurons called within the central nervous system and within the peripheral nervous system

Within the CNS, nuclei, ganglions in the PNS

What are groups of axons called within the central nervous system and in the peripheral nervous system?

Tracts within the CNS, Nerves in the PNS

Fluid-filled space surrounding the brain that cushions the brain

subarachnoid space

What produces cerebrospinal fluid

The choroid plexus in the third ventricle

How is CSF reabsorbed into the blood supply?

arachnoid granulations

Divisions of the CNS: Forebrain, Midbrain, Hindbrain (cephalon)?

Telencephalon/Diencephalon, Mesencephalon, Metencephalon/Myelencephalon

Relay station in hindbrain, between the cortex and cerebellum

Pons

Functions of the cerebellum

Balance and posture - Integrates sensory information and muscle movements, coordinates and has a smoothing effect on the movements

Functions of the Pons

Relay station between cerebellum and cerebral cortex, regulates body movement, attention, sleep/alertness

Medulla functions

Controls vital processes (heartbeat, breathing, blood pressure), borders the spinal cord

What processing do the superior and inferior colliculi of the tectum help with

Superior - visually processing
Inferior - auditory processing

Core network of neurons in midbrain, key functional structures named after colors. Keeps us alert and coordinates movements.

Tegmentum in the midbrain

red nucleus (coordinates body movements), periaqueductal gray (blocks pain), reticular formation (controls sleep and wake cycles), and substantia nigra (uses dopamine to smooth out movements

Does gray or white matter contain myelinated axons

white matter - gray matter has cell bodies and capillaries

Bundle of axons that connect the left and right cerebral hemispheres

Corpus Collosum

What are the 3 areas of the forebrain sensory cortex that receive information from sensory organs

1. Primary visual cortex

2. Primary auditory cortex

3. Primary somatosensory cortex

What fissure/sulcus houses the primary visual cortex?

calcarine fissure

What fissure houses the primary auditory cortex

The lateral fissure

What brain portion produces posterior pituitary hormones and directly controls their secretion

hypothalamus

Thalamus functions

Relay station of the brain, prioritizes like a filter, receives info from sense organs. Sends info to the cortex via projection fibers

Limbic system functions

regulates emotional experience

What does the insular cortex receive information about? Is it in the forebrain or midbrain or hindbrain?

Taste, equilibrium, visceral sensation

What sulcus separates the frontal lobe from the parietal lobe

central

How many pairs of cranial nerves are there? OOOTTAFVGVAH

12 - Olfactory Optic Oculomotor Triochlear Trigeminal Abducans Facial Vestibulocochlear Glossopharyngeal Vagus Accessory Hypoglossal

Preganglionic neurons are located where

in the CNS

Both parasympathetic and sympathetic preganglionic neurons release this neurotransmitter:

acetylcholine

What neurotransmitter does a parasympathetic post-ganglionic neuron release

acetylcholine, to the target organs

What neurotransmitter does a sympathetic post-ganglionic neuron release

norepinephrine

What disease is caused by a degeneration of certain neurons that send axons to the caudate and putamen

Parkinson’s disease

What is the cell body of a neuron called?

Soma

Axonic/Axoplasmic transport can be anterograde or retrograde. Which is slower?

Retrograde is half as slow as anterograde transport

Glial cells in the CNS

oligodendrocytes

Glial cells within the PNS

Schwann cells

What is the longest nerve in the body

Sciatic nerve

What type of reflex goes directly from a sensory neuron to a motor neuron

Monosynaptic reflex

What type of reflex goes from a sensory neuron to an interneuron and then to a motor neuron

Polysynaptic

Functions of astrocytes

• phagocytosis on dead neuron debris

• specialized ones form scar tissue

• chemical nourishment to neurons

• regulate chemical composition of fluid surrounding neurons

How many myelin segments can 1 oligodendrocyte produce

50

What are the smallest glial cells

Microglia

What is the structure of PNS myelin regarding Schwann cells?

Each PNS myelin is a single Schwann cell wrapped many times around one axon

Region of the medulla where blood-brain barrier is weak; poisons can be detected there and can initiate vomiting

Area postrema

Does sympathetic or parasympathetic result in decreased urine production

sympathetic

What is the synthesis pathway for acetylcholine?

Acetate + choline → acetylcholine

Acetylcholine is synthesized by what enzyme

choline acetyltransferase

What enzyme breaks down acetylcholine

acetylcholinesterase

Nicotinic receptors are ______ type receptors that initiate _____ postsynaptic potentials

ionotropic, excitatory

Muscarinic receptors are _____ type receptors that initiate _____ postsynaptic potentials

metabotropic, excitatory

What is the synthesis pathway for glutamate

Glutamine →

What is the synthesis pathway for serotonin

Tryptophan → 5-HTP →

Serotonin activates 7 different families of 5-HT(1-7) receptors comprising of at least 14 distinct subtypes. Almost all serotonin receptors are metabotropic except for one which is an _______receptor.

ionotropic

The ionotropic 5-T receptor for serotonin opens a cation channel and is therefore _______ in nature

excitatory

Use the drop down list to select the most correct answer.

Norepinephrine Neurotransmitter Characteristics

What is the synthesis pathway for norepinephrine?

Tyrosine → L-DOPA → Dopamine →

norepinephrine activates 2 different receptor families.

Alpha-adrenergic receptors are _______ type receptors that initiate excitatory and inhibitory postsynaptic potentials

metabotropic

norepinephrine activates 2 different receptor families.

Beta-adrenergic receptors are metabotropic type receptors that initiate _______ postsynaptic potentials

excitatory postsynaptic potentials

Glutamate activates several different receptor types.

1. NMDA receptors are _______type receptors that initiate excitatory postsynaptic potentials.

ionotropic

Glutamate activates several different receptor types.

1. NMDA receptors are ionotropic type receptors that initiate ______ postsynaptic potentials.

excitatory

Glutamate activates several different receptor types.

1. NMDA receptors are ionotropic type receptors that initiate excitatory postsynaptic potentials.

2. AMPA receptors are ______ type receptors that initiate excitatory postsynaptic potentials

ionotropic

Glutamate activates several different receptor types.

1. NMDA receptors are ionotropic type receptors that initiate excitatory postsynaptic potentials.

2. AMPA receptors are ionotropic type receptors that initiate ______ postsynaptic potentials

excitatory

Glutamate activates several different receptor types.

1. NMDA receptors are ionotropic type receptors that initiate excitatory postsynaptic potentials.

2. AMPA receptors are ionotropic type receptors that initiate excitatory postsynaptic potentials

3. mGlu receptors are metabotropic type receptors that initiate _____ postsynaptic potentials

excitatory

GABA Neurotransmitter Characteristics

What is the synthesis pathway for GABA

Glutamine → glutamate →

GABA-A receptors are _____ type receptors that initiate inhibitory postsynaptic potentials

ionotropic

GABA-A receptors are ionotropic type receptors that initiate ________ postsynaptic potentials

inhibitory

GABA-B receptors are _______ type receptors that initiate inhibitory postsynaptic potentials

metabotropic

GABA-B receptors are metabotropic type receptors that initiate ______ postsynaptic potentials

inhibitory

What is the synthesis pathway for dopamine?

Tyrosine → L-DOPA →

Receptors in the D1 like family are metabotropic type receptors that intiate _____ post-synaptic potentials

excitatory

Receptors in the D2 like family are _____ type receptors that initiate inhibitory postsynaptic potentials

metabotropic

Receptors in the D2 like family are metabotropic type receptors that initiate inhibitory postsynaptic potentials

inhibitory

If a drug blocks the autoreceptor, is it an agonist or antagonist?

agonist

If a drug inactivates the enzyme responsible for metabolism, is it an agonist or antagonist?

agonist

Characteristics of agonists and antagonists

What is the normal resting voltage across the cell membrane

-70mV

Molecules move from areas of ____ to areas of ____ diffusion

more, less

Common electrochemical gradient: Sodium will move ____ the cell

into

Common electrochemical gradient: Chloride will move ____ the cell

into

Common electrochemical gradient: Potassium will move ____ the cell

out of

Is Ca2+ more concentrated inside or outside of the cell

outside

Sodium-Potassium pumps push __ Na+ ions out for every _ K+ ions pumped in

3, 2

What are the steps of neurotransmitters

1. Neurotransmitter synthesis

2. Neurostransmitter stored in synaptic vesicles

3. Action potential reaches axon terminal

4. Ca2+ enters neuron

5. Neurotransmitter released

6. Neurotransmitter binds to & deactivates a receptor

7. Excess neurotransmitter is removed from synaptic cleft

What type of receptors (ionotropic/metabotropic):

• located directly on the ion channel

• fast signaling

• short term change

• bind to neurotransmitters

• can cause change in membrane potential

ionotropic

Metabotropic receptors

• indirect pathway to neural signaling, longer lasting response

• Neurotransmitter binds to GPCR

• Produces a second messenger molecule which opens an ion channel

• Binds to neurotransmitter

• Can cause change in membrane potential

Autoreceptor

receptor on presynaptic terminal that responds to the neurotransmitter its own neuron released

• usually not connected to ion channels

• Mostly controls amount of neurotransmitter released

Axodendritic synapse

between axon and dendrite

Axosomatic synapse

between axon and soma

Axoaxonic

between terminal boutons of axons, they do not contribute to neural integration

• alter amt of neurotransmitter released

• presynaptic inhibition

• presynaptic facilitation

Identify ions A and B

A is sodium, B is potassium

At point A what is happening

Depolarization of the membrane potential towards the threshold potential

The following are features of neurotransmitter receptors. Choose if each feature is describing an ionotropic receptor or a metabotropic receptor or both.

 

• Bind to neurotransmitters

• Cause fast effect

• Linked to GPCR

• Long lasting effects

• Causes changes in membrane potential

• Initiate a 2nd messenger cascade

• Induce changes in the postsynaptic neuron

Bind to neurotransmitters - Both types receptors

Cause a fast effect - Ionotropic receptors

Linked to G-protein coupled receptor - Metabotropic receptors

Long lasting effects - Metabotropic receptors

Cause changes in membrane potential - Both receptors

Initiate a 2nd messenger cascade - Metabotropic receptors

Induce changes in the postsynaptic neuron - Both receptors

When a ligand gated sodium channel opens, ion enters the neuron which _____ the neuron

depolarizes

After ligand gates K+ channel opens, ion will exit the neuron, which will ____ the neuron

hyperpolarize

After a ligand gates Cl- channel opens, ion will ______ the neuron which will hyperpolarize it

hyperpolarize

GABA stands for

Gamma-aminobutyric Acid, the main inhibitory neurotransmitter within the brain