Neural Substrates & Neurochemistry Flashcards
what part of brain creates order and wakefulness (arousal)?
Reticular Activating System
What structure of brain is in charge of alertness and threat assessment (arousal)?
Amygdala–basolateral nucleus
What structure of brain is in charge of filtering out background noise (selective attention)?
brainstem nuclei
What structure of brain is in charge of shifting attention (selective attention)?
hippocampus
What structure of brain is in charge of goal directed behavior (selective attention)?
prefrontal cortex
pathway for unconditioned fear
NT’s involved?
cortex -> amygdala central nucleus*** -> hypothalamus -> PAG -> locus coeruleus -> ANS, NE
NE and 5HT
pathway for conditioned fear
NT’s involved?
cortex -> amygdala-basolateral nucleus -> amygdala-central nucleus -> hypothalamus -> ANS
GLUTAMATE (NMDA)**, NE, 5HT
which structure of brain is firing more when seeking?
lateral hypothalamus
reward/seeking system: Mesolimbic dopamine pathway (just know structures not order?)
ventral tegmental area lateral hypothalamus medial forebrain bundal frontal cortex \+ amygdala + nucleus accumbens
key pathway in predatory aggression
note: related to seeking pathway. addiction loop.
corticomedial (CM) nucleus of amygdala -> lateral hypothalamus -> ventral tegmental -> back to cortex -> back to amygdala
pathway in affective aggression
amygdala-Basolateral nucleus -> MEDIAL hypothalamus -> PAG -> aggression
damage of this structure -> social unresponsiveness, loss of emotional inflection. in monkeys, lose affection and maternal care
cingulate gyrus (remember, i love you with all of my cingulate gyrus!)
structures involved in storing long term declarative memory (HEMP)
initial memory: diffuse cortical areas
long term potentiation (HEMP): Hippocampus
Medial thalamus = Entorhinal complex + Parahippocampal gyrus
Which 2 brain areas create a critical “bottleneck” in memory processing?
note: Most memory dysfunctions involve abnormalities in these structures
- Hippocampus
2. medial thalamic structures
Korsakoff’s syndrome:
a. what do you have trouble with?
b. lack of which NT?
c. due to deficiency of what?
d. which 2 structures are damaged?
a. making new declarative memories
b. ACh
c. thiamin (B1)
d. mamillary bodies, dorsomedial thalamus
brain structure damaged in Dementia/Alzheimer’s.
NT?
basal nucleus of Meynert
ACh
how does stimulating entorhinal complex form memories/long term potentiation? (hint: involves NMDA)
Stimulate entorhinal -> stimulates hippocampal NMDA receptors -> increase Ca2+ receptors -> activate ca dependent PKA’s -> change gene expression -> increased proteins and synapses
2 ways that amygdala can modify memory and any NT systems involved:
- part of conditioned fear pathway
2. increased memory strength by epi, NE, glucocorticoids
what is the tuberoinfundibular pathway?
hypothalamus -> releases dopamine -> pituitary -> prolactin release inhibited
what is Mesolimbic/ Mesocortical pathway?
ventral tegmental area -> dopamine to limbic and cortical sites -> modifies behavior and emotions
- dopamine turns into NE by _____________
- MAO on dopamine -> a)_______ then COMT -> b)_______
- COMT on dopamine -> a)______ then MAO -> b)________
- dopamine beta hydroxylase
- a) Dihydroxyphenylacetic acid (DHPA)
b) Homovanillic acid (HVA) - a) 3-methoxytyramine
b) HVA
Where do D1 receptors predominate?
Where do D2 receptors predominate?
D1: areas related to behavior = frontal cortex and limbic sites
D2: areas for mvt = striatum
how is 5HT mainly controlled/deactivated?
reuptake
primary metabolite of 5HT
5HIAA = 5-hydroxyindoleacetic acid
2 main pathways of ACh and what happens if they’re damaged
- Basal forebrain: basal nucleus of Meynert and co. -> cortex and hippocampus
damage = Alzheimer’s
. - local circuits in basal ganglia
important for modulating motor movements. opposes striatal effects of dopamine
which subtype of cholinergic receptors are targed by psychiatric drugs?
peripheral and central muscarinic
What other substrates besides GABA bind to its Chloride channel (GABA-A)? (BBAN)
note: withdrawal from these can kill you
Barbiturates (CNS depressants)
Benzodiazepine
Alcohol
Neurosteroids
2 main pathways of GABA
- Cortex and limbic system -> emotion and cognition
2. basal ganglia -> Huntington’s disease
most abundant inhibitory NT?
GABA
most abundant excitatory NT?
Glutamate
what receptor and channel does PCP (phencyclidine) act on and what 2 conditions is it used to treat?
schizophrenia and psychosis. inhibits NMDA receptor which is linked to calcium channel
too much glutamate has what effect on neurons? what situation does this occur in?
in cerebral ischemia. it kills neurons :(
which 2 places of brain is glutamate especially plentiful?
pyramidal cells of cortex
hippocampus
glutamate is involved in long projection tracts that function to do what?
cortical neurons project to subcortical structures to modulate their activity
neuropeptide transmitters exist in the brain in concentrations ______ times less than monoamine NTs.
10-100 times
is neuropeptide transmitters fast or slow compared to other NTs and why?
sluggish.
b/c dependent on protein synthesis rather than rapid enzymatic rxns
how do CNS peptides modulate stuff? 3 ways.
they are released with the other main NTs. they can alter:
- rate of production of main NTs
- amount of NTs released by stimulus
- response of target cells to the NTs
what part of brain especially rich in peptides?
limbic areas
