Definitions
What is a neuronal pool?
Thousands to millions of interneurons that share a specific body function.
- i.e. control rhythm of breathing
What are discharge and facilitated zones? (3 bullets)
Different pathways that are taken between presynaptic & postsynaptic neurons depending on what the need is.
Discharge zone: only a single cell can produce firing
Facilitated zone: a single cell can only make it easier for the postsynaptic cell to fire, needs all the neurons
What is the difference between diverging and converging circuits?
A diverging circuit is one cell that synapses on another that each synapses on others,
whereas a converging circuit is input from many fibers on one neuron (that is the respiratory center).
How do our brains process information from chemical & electrical signals?
WE DON’T KNOW AND CANNOT TELL
We can only sum up how information gets to the brain, and the qualitative information depends on the strength of the stimuli and the recruitment of neurons.
What does presynaptic inhibition look like?
One presynaptic neuron suppresses another one. Neuron 1 releases inhibitory neurotransmitter GABA, which prevents voltage-gated calcium channels from opening.
Cholinergic
a compound or synapse that employs acetylcholine as its neurotransmitter
- part of the receptor system
What is the most superior part of the brain stem?
The midbrain, containing the substantia nigra.
The substantia nigra releases the dopamine neurotransmitter to the deepest part of the cerebrum, called the basal ganglia
What are reverberating and parallel after-discharge circuits?
- Neurons stimulate each other in a linear sequence but one cell restimulates the first cell to start the process all over
- input neuron stimulates several pathways which stimulate the output neuron to go on firing for longer time after input has truly stopped
What are the symptoms of Alzheimer's Disease?
Memory loss for recent events, moody, combative, lose ability to walk, and eat
Can a diagnosis of Alzheimer’s be given before death?
No. There can be testing done, but the actual diagnosis is confirmed at time of autopsy, when professionals can observe atrophy of the gyri (folds in the brain).
Afferent
sensory information that carries signal towards the central nervous system
What are the three (less irrelevant) types of neurotransmitters?
- monoamines
- neuropeptides
How does Parkinson’s affect the body?
It can cause progressive loss of motor function beginning in 50s or 60s with no recovery. Despite that, there are many treatment options.
How many people are affected by Alzheimer’s Disease?
100,000 deaths/year
11% of the population over 65; 47% by age 85
What does the excitatory cholinergic synapse process look like?
Nerve signal opens voltage-gated calcium channels
- triggers release of ACh which crosses synapse
- ACh receptors trigger opening of Na+ channels producing local potential (postsynaptic potential)
- When reaches -55mV, triggers AP
Efferent
motor information carries signal away from the central nervous system
How many cells and synapses are present in the cerebral cortex?
What causes Parkinson’s to attack the body?
What is neural integration? Stick to the basics.
- add up the EPSPs and the IPSPs
What does the Inhibitory GABA-ergic synapse process look like?
- GABA receptors trigger opening of Cl- (chloride) channels producing hyperpolarization
-Postsynaptic neuron now less likely to reach threshold (inhibitory)
What is saltatory conduction in myelinated fibers?
Voltage-gated channels needed for APs, consisting of very fast sodium diffusion.
What is the physical basis of memory?
What is synaptic potentiation?
Neurotransmitter is NE (excitatory)
- Acts through 2nd messenger system (cAMP)
- cAMP has multiple effects: synthesis of new enzymes, activating enzymes, opening ligand gates, and producing a postsynaptic potential