Problem 3 Flashcards
Why is the classic theory on genetics as a cause for psychiatric disorders not adequate?
Not everyone who has the genetic implications for a psychiatric disorder will develop one
What is the Two-Hit hypothesis?
The two hit hypothesis states that the genetiv vulnerability for a disorder is only “the first hit”, this vulnerability develops into a disorder when more hits are sustained from stressors throughout life.
Describe some types of neurodevelopmental disorders and the psychiatric disorders associated with it
Wrong migration: epilepsy, mental retardation, schizophrenia, & dyslexia
Abnormal synaptogenesis: mental retardation, autism, maybe schizophrenia
What are 3 ways to theorethically ‘fix’ neurodegenerative diseases?
- stop abnormal gene production or block the unwanted actions of the gene products
- make neurotropic factors rescue degenerating neurons and halt the progression of the disorder
- transplantation of the new neurons, to compensate or replace the functions of the degenerating neurons
What are Corticocortical loops?
A circuit between different (corical) areas where the information is sent downstream and the originating point receives feedback
What kind of cells form the beginning and end of the CSTC loop?
Pyramidal cells
Are pyramidal cells excitatory, inhibitory or both?
Excitatory
How do pyramidal cells receive inhibiting input?
Nearby GABAergic neurons generate short distance inhibiting input, they inhibit the pyramidal cells indirectly.
How is the CSTC loop being fine tuned?
Graded degrees of monoamines and other neurotransmitters can have inhibitory and excitatory input. With this input they signal with information to prioritize and which to ignore, this is called enhancing the signal to noise ratio.
What is the Dopamine projection pathway?
HPBSN.
The projection originates from the brain stem, then it goes as follows:
Hypothalamus, Prefrontal cortex, Basal forebrain, Striatum, Nucleus accumbens
Dopamine is produced in the VTA and Substantia Nigra
What is the Norepinephrine projection pathway?
HPBTS - originates in brainstem
Hypothalamus, Pfc, Basal forebrain, Thalamus, Spinal cord
Produced in the Locus Coerulus
What is the serotonin projection pathway?
HPBTS - originates in the brain stem
Hypothalamus, Pfc, Basal forebrain, Thalamus, Spinal cord
Produced in the Raphe nuclei
What is the Acetylcholine projection pathway that originates in the brainstem?
BHPBATH
Brainstem, Hypothalamus, Pfc, Basal forebrain, Amygdala, Thalamus, Hippocampus
What is the Acetylcholine projection pathway that originates in the Basal forebrain?
BHAP
Basal forebrain, Hippocampus, Amygdala, Pfc
What is stress sensitization?
When circuits are repeatedly stressed, the load becomes to much and the circuit becomes stress sensitized, this causes the circuit to work overtime even after the stressor is withdrawn, this does not cause symptoms immediately but it does cause loss of resilience
What is diabolical learning?
When symptoms of disorders are left untreated, they can cause plastic changes. Recruiting more sick circuits, eliminating healthy compensating mechanisms, phosphorylating critical regulatory proteins and erecting better synaptic scaffolding in sick circuits to make them more efficient.
What is a agonist?
An agonist is a ligand that has a normal effect on the receptor
What is an antagonist?
An antagonist is a ligand that binds to the receptor but does not do any work, it doesnt activate it. But it blocks any agonists or inverse agonists from binding to it
What is an inverse agonist?
The inverse agonist binds to the receptor and does the opposite of the agonist. It actively closes the channel (even disrupting the consitutive activity)
What is affinity?
Affinity is the chemical attraction between the ligand and the receptor
What is efficacy?
Efficacy is the tendency of a ligand to activate the receptor to which it is bound
What is a partial agonist?
A agonist that only partially activates the receptor, always staying below the maximal capacity a full agonist would have.
What is functional tolerance? (Up and down regulation)
Down regulation: repeated exposure to an agonist causes the target neurons to decrease the number of receptors it can bind to
Up regulation: repeated exposure to antagonists causes the number of receptors to go up to increase the probability of an agonist binding
Why can a partial agonist be a net agonist or net antagonist?
The partial agonist can have both an agonistic and antagonistic effect because when there are no full agonists present they act as agonists, however when there are full agonists around the partial agonist causes a less effective response and thus having the same effect an antagonist would have.
