Midterm 1 Flashcards
Do catecholamines have metabotropic or ionic receptors?
Metabotropic
Catecholamine neurotransmitters are broken down by enzymes called
MAO Monoamine oxidase or catechol-o-methyltransferase
Catecholamines all contain
a catechol ring and an amine group
Epinephrine and NE bind to receptors called
Adrenergic
___ is a naturally occurring antagonist of muscarinic acetylcholine receptos
Atropine
Characteristics of biogenic amines
Small, charged molecules that are synthesized from amino acids and contain an amino group R-NH2
Disease associated with acetylcholine
Alzheimers. Many cholinergic neurons in the brain begin to degenerate. As a result, less ACh will be produced and language and cognitive abilities decline
Serotonin is also known as
5-HT
Serotonin is produced by
Tryptophan
Serotonin effects usually have a slow onset, indicating that it is a
Neuromodulator
Serotonin is located mostly where
Located mainly in the gut and PNS. Absent during sleep. Usually has an excitatory effect on pathways that control muscles and an inhibitor effect on pathways that mediate sensations.
Histamine is derived from
Histadine
___ is a serotonin reuptake inhibitor
Prozac
What AA neurotransmitter is excitatory?
Inhibitory?
Excitatory- glutamate
Inhibitory-Glycine and GABA
Glutamate receptors are mainly
Ionotropic
Glutamate receptors on the postsynaptic membrane
AMPA & KA receptors are bound to the post synaptic membrane. Glutamate neurotransmitter binds to both channels. The channels becomes permeable to both Na+ and K+, but the larger entry of Na+ depolarizes the cell.
NMDA require the magnesium ion blocking the channel to be removed. To drive it out of the way, the membrane must be significantly depolarized. If it is, then the Mg2+ ion will leave and Ca2+ will enter the cell and start a second messenger cascade. This creates a long lasting increase in the sensitivity of the post synaptic neuron and might be involved in learning and memory
Neurotransmitter that might be involved in learning and memory
Glutamate (excitatory AA neurotransmitter)
GABA other name
Gamma amino butyric acid. Type of inhibitory AA neurotransmitter
GABA is a modified form of
glutamate
GABA receptors
Ionotropic
Glycine receptor type
Ionotropic
Neurulation
Ectoderm development
Stage where embryo blast of the blastula differentiates into epiblast and hypoblast
Bilaminar disc stage and late stage of implantation
zygote
1 cell
baby becomes a fetus at week ___ and is considered a fetus until birth around week __
9, 39
When does primitive streak arise
Week 3. Marks beginning of gastrulation
Neural crest cells can produce
Mesenchume –> connective tissue
Ventricular/ ependymal/matrix cells in the ectoderm produced neural tube
Matrix layer in the neural canal proliferate into neuroblasts and glioblasts to become to ependymal layer in the ventricles and form the choroid plexus
Mantle intermediate layer of the neural tube
Formed from neuroblasts that migrate from the matrix layer and form the gray tissue of the spinal cord (neuron soma and dendrites)
marginal layer of the neural tube
Forms the white matter, axons
Notochordal mesoderm forms
The notochord
Paraxial mesoderm gives rise to
Somites (segmental division of the body)
Lateral plate mesoderm gives rise to
Visceral mesoderm- epithelial lining of organs. Heart, blood vessels, muscles of organs.
parietal/somatic mesoderm- serious membrane of pleura. Lines the cavities.
Structures created by the ectoderm
Sensory epithelium of the eyes, nose, and ears.
Skin, hair, nails.
Pituitary gland and subcutaneous glands
Structures created by the mesoderm
Connective tissue proper and special (cartilage, bone, blood, lymph) Muscle tissue (skeletal, smooth, cardiac)
Structures created by the endoderm
Lining of the respiratory and digestive tract
Stomach, liver, pancreas, intestines
Thyroid and parathyroid
9+2 array
Microtubules- flagella and cilia
9+0 array
Centrosomes (microtubule)
Explain roles by synaptobrevin, Syntaxin, SNAP 25, and synaptotagmin
Synaptobrevin and synaptotagmin are proteins on the VESICLE.
Syntaxin and SNAP 25 (MBP) are on the pre synaptic membrane active zone.
Synaptobrevin holds onto syntaxin and SNAP 25 to dock the vesicle at the membrane. It cannot release its contents until Ca2+ binds to synaptotagmin. This gives the OK.
Neuroactive peptides
Endothelial NOS
Neuronal NOS
Inducible NOS
Albumin
Protein made by your liver that helps keep fluid in your blood stream so it doesn’t leak into other tissues. It carries various substances throughout the body including hormones, vitamins and enzymes.
If albumin exits the vasculature, liquid will follow, creating edema in body cavities
Proteins are not found in the ____
Interstitial fluid. It is found in the plasma and intracellular fluid.
If proteins, such as albumin are found in the interstitial fluid, that means that liquid will exit the bloodstream to follow and cause edema.
Cl- levels are high in the
Plasma and interstitial fluid
What membrane is between the plasma (intravascular) and interstitial fluid?
Capillaries
Tight junctions
Water-tight seal between two cells. prevents fluids from leaking through. Example: urine from leaking out of bladder.
Gap junctions
Channels between cells that allow the transport of ions, nutrients, and other substances that enable cells to communicate.
Ocular disease associated with Aquaporin abnormalities
NMO- neuromyelitis optica. (Devics disease).
Optic nerve and spinal cord demyelination. Distinct brain lesions to ventricle that are different from MS.
Antibodies target AQP4 specifically in ventricle. Ventricles have high AQP4 because they make CSF.
MS can be anywhere in the body, but NMO is seen mostly on optic nerve and spinal cord.
What cell were aquaporins discovered in and by who?
Red blood cell.
Peter Agre discovered in 1988. Got Nobel prize in 2003.
Benga’s group discovered the channel in 1985, but was overlooked.
CSF is produced where
In the choroid plexus. Sent o ventricles, subarachnoid space, canals, and then drain into spinal cord along superior sagittal sinus.
Where are aquaporins found in the eye?
Cornea, lens, iris, retina, conjunctiva
How can aquapaporin disfunction cause diabetes insidious
AQP 2 disfunction results in an imbalance of fluid in the body.
AQP and glaucoma
AQPs form blood perfusates- take ions and proteins from blood and make something of it.
Aqueous humor is a blood perfusate (so is CSF). If aquaporins produce too much aqueous humor = glaucoma
Mature vs immature dendritic spines
Mature- short and fat
Immature- skinny and tall
Dendritic spines
Increase surface area on dendrites. The more spines= the less likely you are to get dementia.
Neurotransmitter criteria
Must be made in the nerve
Stimulation results in postsynaptic response
Can be mimicked
There must be a mechanism to remove neurotransmitter from synapse
Quantal release
Always the same amount of neurotransmitter released in vesicles each time.
Neuronal curcuits
- Diverging
- Converging
- Reverberating. Circle
- Paralell-after-discharge. Single cell stimulates a group of cells that all stimulate a common postsynaptic cell.
Myasthenia gravis
Autoimmune disease that results in the decline of muscle strength. Body produces antibodies against the ACh receptor.
Frequently results in diplopia (double vision) and ptosis ( drooping/falling of upper lid.)
neostigmine is the medication used to treat this.
Multiple sclerosis
Autoimmune disease results in the loss of transmission. Body produces antibodies against myelin basic protein found in neurons.
Clostridium tetani (tetanus toxin)
prevents vesicle fusion with the membrane, inhibiting neurotransmitter release. Causes increased muscle contraction.
Examples of diseases that affect synaptic mechanisms
Tetanus toxin by clostridium retain
Bacilli toxin, botulism by costridium botulinum. Interferes with actions of SNARE proteins at excitatory synapses that activate muscles. Characterized by muscle paralysis.
Excitatory and inhibitory neurotransmitters
Excitatory: Glutamate, ACh, and aspartate (decreases post synaptic potential)
Inhibitory: GABA, glycine (raises or stabilizes post synaptic potential)
Peptides are modulatory
Precursor to ACh
Acetyl coa + Chline
Nicotinic receptors are blocked by
Curare, hexamethonium
Nicotinic receptors- excitatory or inhibitory?
ACh can bind, resulting in ESPS
Parkinson’s disease
Involves the loss of dopamine-releasing neurons. Involves persistent tremors, head nodding and forward bent walking posture. Treated with L-dopa and also with deprenyl, which prevents the breakdown of L-dopa.
Serotonin functions
Regulates sleep and emotions
Vomiting reflex
Vascular smooth muscle cell contraction
Most abundant type of neurotransmitters
Amino acids. Ex: Glutamate and aspartate are both excitatory.
GABA is created from ___ by ___
Glutamate by glutamate decarboxylase
Benzodiazepine (valium) works on what inhibitory receptor?
GABA. This activates GABA and prevents depolarization. Helps sleep and anti-anxiety.
Glycine is blocked by
Strychnine
