Neurochemistry
Synaptic cleft by Acetylcholinesterase (AChE)
What degrades Acetylcholine and where?
Acetylcholine
What is the most widespread neurotransmitter in the nervous system?
-Motor neurons of spinal cord to innervate muscle of body
-Motor neurons of cranial nerves to innervate muscles of head/neck
-Motor neurons of cranial nerves to innervate muscles of head/neck
What nerves use Acetylcholine?
-Autoimmune disorder, antibodies block AChR (receptors for ACh)
-Muscle weakness develops
-treath with AChE inhibitors to keep ACh in synapse longer
-Muscle weakness develops
-treath with AChE inhibitors to keep ACh in synapse longer
What is Myasthenia Gravis? and what are its symptoms and treatments?
Paralysis
What happens when ACh is blocked by AChR blockers?
-many CNS synapses
-involved in regulating alertness/attention, sleep, learning/memory
-involved in regulating alertness/attention, sleep, learning/memory
Where is ACh used? What is it used for in the brain?
Neurons die from overdose of ACh
Physical signs-
-neurofibrillary tangle-intracellular
-B-amyloid plagues – extracellular
-cortical wasting due to death of acetylcholine neurons
-Memory loss
Treat
-treat with AChE inhibitors
Physical signs-
-neurofibrillary tangle-intracellular
-B-amyloid plagues – extracellular
-cortical wasting due to death of acetylcholine neurons
-Memory loss
Treat
-treat with AChE inhibitors
What happens in Alzheimer’s disease? what are some of the physical signs? and what are the treatments?
Glutamate!
What is the most common neurotransmitter in the brain?
Excitatory Amino Acid
-increases action potential firing probability
-increased release induces epilepsy
-Up-take by glia or presynaptic neuron
-increases action potential firing probability
-increased release induces epilepsy
-Up-take by glia or presynaptic neuron
How does Glutmate function as a neurotransmitter?
Motor neurons preferentially die, no definitive cause known
What is Amyotrophic Lateral Sclerosis (ALS?)
Inhibitory Amino Acid
-made from Glutamate
-decreases action potential firing probability
-up-take by glia or in presynaptic neuron
-made from Glutamate
-decreases action potential firing probability
-up-take by glia or in presynaptic neuron
How does GABA (and Glycine) function as a neurotransmitter?
-Benzodiazepine (valium)
-Barbiturates
-Alcohol
-Barbiturates
-Alcohol
-Sedation, anesthesia, anti-anxiety
What substances inhibit interactions between neurons and add to GABA inhibition? what are their uses?
Tyrosine→L-DOPA→Dopamine→norepinephrine→epinephrine
Degraded intracellularly within neurons or up-take by glia
What is the Catecholamines progression? where is it degraded?
Substantia Nigra
What is the main source of dopamine?
Parkinson’s disease develops
What happens when dopamine levels are decreased because of the death of the subtantia nigra neurons?
Schizophrenic symptoms
What happens when someone has an increased level of dopamine?
Locus Coeruleus
What is the main source of Norepinephrine (Noradrenaline)?
Depression
What happens with decreased NE?
Mania
What happens with increased NE?
the role of Epi is not well characterized in the CNS
What is the role of Epinephrine in the CNS? (Adrenaline)
plays a role in autonomic/sympathetic “Fight or Flight” stress responses
What is the role of Epinephrine in the PNS? (Adrenaline)
Brainstem raphe nuclei
What is the main source of Serotonin?
Pain inhibition, sleep and depression
What is Serotonin involved in ?
Conveys pain from the periphery to the CNS
What does Substance P do?