CNS Flashcards
(84 cards)
Neuropharmacology Definition
study of how drug affects function of CNS
5 mechanisms in which drugs act in CNS
Replacement (Drug replaces neurotransmitter) ,
Agonist/Antagonist (binds to receptor in the post-synaptic membrane)
Inhibit neurotransmitter breakdown
Blocking Reuptake (stops it from taking back into the pre-synaptic membrane, stay in synaptic cleft longer)
Nerve Stimulation (Stimulate nerve to release more neurotransmitters)
Symptoms, pathophysiology, and etiology of Parkinson
Symptoms, pathophysiology, and etiology of Alzheimer
Symptoms, pathophysiology, and etiology of Schizophrenia
MOA for Alzheimer’s drugs
MOA for Parkinson’s Drugs
What are Neurons?
Neurons are cells in the brain that act to process and transmit signals and information
How does a neuron transmit information?
By chemical or electrical signaling. It starts with the dendrite receiving a signal from another neuron. This causes AP to propagate along the axon and when AP reaches the synaptic nerve terminal, it causes the release of neurotransmitters which pass the signal along to the next neuron.
Resting potential of a cell
-70 mV
Threshold
If depolarizing stimulus is received, sodium gated channel opens and it allows sodium to enter cell. Na+ is positive so it begins to depolarize making membrane potential to get close to threshold.
Rising Phase
If threshold is achieved, other sodium channels open and sodium rush in. Membrane potential increases.
Falling Phase
Sodium channel closes and potassium channle open. K+ comes out of cell and membrane potential decrease back down, as membrane potential get close to resting potential more potassium channel open.
Hyperdepolarization
Membrane potential went under resting potential due to excess potassium leaving cells
Steady State
As it enter steady state, Potassium channels closed
How does a neuron transmit singals.
AP reach to presynatic terminal, causes influx of Ca+ which causes neurotransmitter containing vesicle to fuse with presynaptic membrane, vesicle releases neurotransmitter into the synaptic cleft. Neurotransmitters bind to receptors on the post-synaptic nerve membrane and signal continues.
Classes of neurotransmitter
Monoamines: Norepinephrine, Epinephrine, Dopamine, Serotonin
Amino acid - Excitatory, Inhabitory
Other - Acetylcholine
Neurotransmitters
chemical that transmits signals across the synapse.
Monoamines and related diseases
Norepinephrine- Depression and Anxiety
Epinephrine - Anxiety
Dopamine- Parkinson, Schizophrenia
Serotonin - Depression and Anxiety
Amino Acid and related diseases
Excitatory - glutamate (Alzheimer)
Aspartate - Alzheimer
Inhibitory - GABA (anxiety), Glycine (anxiety)
Other neurotransmitters and related disease
Acetylcholine - Alzheimer and Parkinson
Pathophysiology of Parkinson’s Disease
- PD is a chronic movement disorder.
- Caused by imbalances between acetylcholine and dopamine in the brain.
- Symptoms arise because 1. dopamine release decreases, not enough dopamine to inhibit GABA release. 2. excess acetylcholine = increased GABA release 3. Excess GABA= movement disorder
Symptoms of Parkinson
chronic movement disorder
Tremor - in extremities hands, arm,legs, jaw, face
Ridigity - joint stiffness and increase muscle tone
Bradykinesia -slowness to initiate movement
Masklike face - can’t show facial expression, have difficulty blinking and swallowing
Postural Instability - balance is impaired, difficulty balancing with walking
Dementia - later stages
Etiology of Parkinson
Mostly unknown but some possible causes might be
- Drugs (MPTP, by-product of illicit street drugs, MPTP causes the irreversible death of dopaminergic neurons.)
- Genetics ( alpha synuclein, parkin, UCHL1, DJ-1 mutation)
- Environmental Toxin ( pesticide)
- Brain Trauma ( direct trauma - like boxing )
- Oxidative Stress ( Reactive oxygen species cause degeneration of dopaminergic neuron. eg, diabetes)