neurobiology Flashcards
demyelination of axons in PNS is called
Gullian-Barre Syndrome (GBS) (due to prior infection / Inflammatory process )
Main Symptoms of Gullian-Barre Syndrome (GBS)
● Progressive ascending motor weakness;
● Motor and sensory loss affecting the face,
limbs, trunk, and diaphragm;
● Areflexia due to damage of both reflex
arcs of the deep tendon reflex;
● Inflammatory cells (lymphocytes and
macrophages) found within peripheral
nerves.
Disorders Associated With Defective Myelination
Charcot-Marie-Tooth Syndrome
Gullian-Barre Syndrome (GBS)
Multiple Sclerosis (MS)
autoimmune demyelination of axons in CNS
Multiple Sclerosis (MS)
Main symptoms of multiple sclerosis MS
● numbness in one or more limbs;
● tingling or pain in parts of the body;
● partial or complete loss of vision in one eye at a
time and double or blurred vision
● speech disturbances
demyelination in PNS caused by gene mutations
Charcot-Marie-Tooth Syndrome
Charcot-Marie-Tooth Syndrome is due to mutation of what gene ass. with schwann cells
Connexin ( therefore failure of gap junctions)
main symptoms of
Charcot-Marie-Tooth Syndrome
● Demyelination affects both motor and
sensory nerves;
* weakness of the foot and lower leg
muscles is typical;
● patients have a high- stepped gait with
frequent tripping or falls;
* deformities in the foot and digits
Disorders Associated With Defective Ion Channels:
Lambert-Eaton Syndrome
Cystic fibrosis
Cystic fibrosis affects what channels
inherited disease with impaired functions of Cl- ion channels
Organs commonly affected with recurrent infection ass. in cystic fibrosis is
Lungs and airway
CFTR (cystic fibrosis transmembrane conductance
regulator ) gene provides instructions for making
CFTR protein, which is located in the cell membrane
and functions as an ion channel through which Cl- ions and water are transported to maintain the
fluidity of mucus and secretions
Function of the Cystic fibrosis transmembrane conductance regulator gene
Provides instructions for making
CFTR protein, which is located in the cell membrane
and functions as an ion channel through which Cl-
ions and water are transported to maintain the
fluidity of mucus and secretions;
Lambert-Eaton Syndrome affects what channels
loss of voltage-gated Ca2+ channels in the presynaptic terminals
at the NMJ and other synapses;
Lambert-Eaton Syndrome is ass. with
small-cell carcinoma of the lung :derived from neuroendocrine cells expressing voltage-gated Ca+ channels);
Main symptons of lambert-eaton syndrome
dry mouth, constipation, reduced
sweating, orthostatic hypotension, and impotence
reduction in the release of the transmitter (Ach)
at the NMJ causing muscle weakness
Diseases Affecting the Chemical Transmission at the NMJ
Myasthenia Gravis
Lambert-Eaton Syndrome
Myasthenia Gravis involves
antibodies that reduce d number of nAchRs in the postsynaptic membrane
In myasthenia Gravis muscle weakness is increased during _____ and reduced by ____
muscle weakness increased during exercise and
reduced by rest.
Main symptoms of myasthenia gravis
● Muscular weakness due to a decrease in the
response of the muscle fiber to Ach;
● weakness of the eyelids, eye muscles,
oropharyngeal muscles, and limb muscles;
Diseases Associated With Toxins:
Botulinum
Tetanus
Disease Caused by anaerobic clostridium
bacteria in contaminated food
Botulism
Main symptom in botulism
Neurotransmitter release at the NMJ abolished
● paralysis of the diaphragm causing respiratory fail-
ure and skeletal muscle weakness;
● visceral motor dysfunction occurs due to the
blockade of synapses in smooth muscles
spinal interneurons affected in botulinum
spinal interneurons affected in tetanus
ACh
GABA & Glycine
Ability of neurons to establish new and more stronger connections
Neuroplasticity
