Topic 3: Part 2 Flashcards
T or F: the same NT can have different roles in different parts of the body.
True
A chemical that has the same effect on the postsynaptic neuron as the neurotransmitter does
A Neurotransmitter Agonist
(Many drugs are NT agonists but they often flood the entire body and many undesirable adverse reactions
What is Opiorphin?
it’s an endogenous painkiller recently found saliva. It is released in small amounts to control everyday painful stimuli in the mouth.
Barely penetrates the BBB
A molecule that blocks the effect of an NT or it’s agonists
An Antagonist
Example: Naloxone is an opioid antagonist used to counter the effects of opioid overdose.
Axon terminals can connect with dendrites of another neuron:
Axodendritic synapse (most common)
Axon terminals can connect with the cell of another neuron:
Axosomstic Synapse
Axon terminals can connect with the axon of another neuron:
Axoaxonal synapse
T or F: the NT can cause either an Excitatory Postsynaptic Potential (EPSP) or an Inhibitory postsynaptic potential (IPSP) at the postsynaptic neuron.
True
T or F: An EPSP (facilitation, hypo-polarization) makes it more likely that an action potential will continue in the post synaptic neuron.
True
An ___________ makes it less likely that an action potential will continue on in the postsynaptic neuron.
IPSP (hyperpolarization)
Frequent postsynaptic potentials at the same synapse occur in rapid succession.
The effect of the first potential does not have time to dissipate and the succeeding potentials add to the previous one.
Temporal Summation
Multiple excitatory signals to various postsynaptic sites
Spatial Summation
If it “fires an AP goes all the way to the end of the axon. This is described as the
All or None Law
A change in the frequency of action potentials usually indicates a change in the intensity of a stimulus
This is the most common inhibitory NT in the CNS and without it, nerve cells could fire too often.
GABA
Gamma-Aminobutyric Acid
Panic attacks, seizure disorders and cognitive impairment are all related to low _________ activity.
GABA
Agonists include prescription medications classified as benzodiazepines (Valium and Librium)
The most common excitatory NT in the CNS.
Too much or too little of it is harmful.
Glutamate
It is involved in most aspects of normal brain function (cognition, memory, learning)
Microglia uses _________ to destroy infected neurons, virus, and bacteria but this can also cause large amounts of collateral damage to healthy neurons
Glutamate
Due to chronic inflammation, microglia can become over activated. This can result in a self perpetuating cycle called
Reactive Microgliosis
This is thought to be an underlying mechanism of progressive neuron damage across numerous neuro-degenerative diseases, regardless of instigating stimuli
Linked to depression
Serotonin deficit
Class of drugs that alleviate depression by increasing the length of time that serotonin stays in the synapse. Prozac is one of these.
Selective Serotonin re-uptake Inhibitors (SSRI)
An excess of the this NT results in the limbic system and not enough in the cortex and has been linked to paranoia and addiction.
In the frontal lobe relieves pain and boosts feelings of pleasure.
Dopamine
- Memory problems
- movement problems as seen in Parkinson’s
- linked to compulsive gambling, shopping and other impulse control disorders.
Results of shortages of Dopamine
Secreted by the Hypophysis or Pituitary Gland
Oxytocin
Significant lower levels of this hormone/NT in blood plasma was found in autistic children. It was found that it helped autistic children retain the ability to evaluate the emotional significance of speech intonation.
Oxytocin
Released during touching hugging, sexing. Social recognition and bonding. May be involved with trust.
Strengthens those close to us. Makes us fearful suspicious of bitches outside yo crew!
Oxytocin.
How do drugs modify synapse function?
- Mimic the neurotransmitter. (Morphine mimics endorphins)
- Blocks re-uptake of NT (Cocaine blocks the re-uptake of dopamine)
- Block Enzyme pathways that degrade NT’s
The NT released at the postganglionic synapses is
Acetylcholine (Ach)
Axons that release ACh are called
Cholingeric Drugs
They are also called parasympatheomimetic drugs because they produce effects that imitate parasympathetic nerve stimulation
The postganglionic neurotransmitter is
Norepinephrine aka noradrenalin
Fibres releasing norepinephrine are called Adrenergic fibres which are also called
Sympathomimetic drugs because they mimic effects similar to those produced by the sympathetic nervous system.
These drugs raise BP and increase the HR for things like cardiac arrest including shock.
What do beta blockers do?
Reduces symptoms connected with hypertension, cardiac arrhythmia and angina pectoris
Must avoid caffeine, alcohol and salty foods.
