Gibbs Brain Flashcards
3 types of memory
working memory, procedural memory, declarative memory
what is declarative memory
memory for facts and events that can be recalled (dates, phone numbers, names)
aka explicit memory
what are the subtypes of declarative memory
episodic and symantic
what is episodic memory
ability to recall information about episodes that are part of your history (name of a pet, grade on a test)
what is symantic memory
ability to recall ideas and concepts not drawn from personal experience (common knowledge like capitals of states and countries)
what is procedural memory
memory for how to do things (tie a shoe, play piano)
aka implicit or unconscious memory
what is working memory
a form of SHORT TERM memory where events are TEMPORARILY stored (holding a phone number in your head until you can write it down, remembering a set of directions while navigating)
functions of the prefrontal cortex
executive functions:
regulates thought (short/long term decisions),
planning ahead, creating strategies,
adjust reactions to situations,
connect emotions with decisions,
house of working memory,
social judgment,
pay attention
what happens when the prefrontal cortex is damaged?
personality changes,
negatively impacts ability to assess situations or perform tasks,
unable to discern appropriate behavior: reduced inhibitions,
extreme emotional distress,
impaired working memory
precentral gyrus is part of _____
pyramidal motor system
precentral gyrus responsibilities
direct innervation of motor neurons in spinal cord, brainstem, cranial nerve nuclei,
initiation of voluntary movements
the precentral gyrus is a ____ system
crossed: cells on right side of brain control muscles on left side of body
what happens with damage to the precentral gyrus
paresis or paralysis on the opposite side of the body
what structures make up the extrapyramidal motor system
cerebellum, pons, spinal cord, thalamus, substantia nigra
functions of the extrapyramidal motor system
modulating voluntary and involuntary movements,
postural adjustments,
fine-tuning motor movements,
motor learning (procedural memory)
extrapyramidal symptoms
tremors, rigidity, loss of gait, uncontrolled movements (dyskinesias), inability to make postural adjustments, disruption of autonomic functions
parts of the limbic system
hippocampus, amygdala, hypothalamus
also olfactory bulbs, anterior thalamic nucleus, septum, fornix, cingulate cortex
where is the hippocampus
medial temporal lobe
functions of the hippocampus
declarative memory consolidation
formation of long-term declarative memories
maintenance of cognitive maps for navigation
what happens with damage to the hippocampus
anterograde amnesia (inability to learn new information)
amygdala functions
perceptions of fear and anxiety
defensive behaviors
social functions such as mating
what happens with damage to the amygdala
depression, aggression, anxiety
functions of the hypothalamus
regulates metabolic homeostasis
controls body temp, hunger, thirst, social recognition, fatigue, sleep, arousal, circadian rhythms
the hypothalamus links what to what
nervous system to endocrine system (via pituitary gland)
what happens with damage to the hypothalamus
severely affects homeostatic functions & hormone regulation
cell types in the brain
neurons
glia
ependymal
what are neurons
electrically excitable cells; process & transmit info thru electrical & chemical signals
what are glia
non-neuronal cells that maintain homeostasis, form myelin, provide support & protection for neurons
what are ependymal cells
specialized cells that line the fluid-filled cavities of the brain and spinal cord
parts of neuron?
dendrites, soma, axon, myelin, nodes, terminal
what are (5) things that make neurons special
polarized
cellular specialization
excitable
unique
do not regenerate
types of glial cells (3)
astrocytes
oligodendrocytes (CNS)
microglia
primary functions of glial cells (4)
surround neurons, hold them in place
supply nutrients
insulate axons (myelinate)
destroy pathogens, remove debris
microglia are the primary ___ in the brain
phagocytic cells
microglia are resident _____
immune cells
microglia play a role in ______
synaptic pruning
2 states microglia exist in
resting, activated
microglia are activated by?
infection, debris, stress
activated microglia release ____?
cytokines, growth factors
activated microglia are linked to?
autism, schizophrenia, parkinson’s, chronic pain
why are the effects of infection and stress on the brain exacerbated with age??
microglial hypersensitivity hypothesis– microglia have memory: previous activation hypersensitizes them to subsequent activation
corticosteroids affect on microglia
can sensitize microglia to INCREASE inflammatory response in brain
what is the peak age of onset for psychiatric disorders
adolescence
why do psych disorders onset in adolescence
btwn 11-13 years old the brain experiences rapid growth of nerve cell projections/connections
a period of neuronal “pruning”
what is pruning
during adolescence, many nerve cells are lost
– a process by which nerve cells that are not used or needed are eliminated
what is the pros of pruning
allows the adolescent brain to function more efficiently for tasks that are already known
psych disorders associated with abnormal pruning?
schizophrenia, ADHD, autism
pruning is modulated by?
GABA mediated inhibitory activity
_____ cells play a role in pruning
microglia
____ hormones can also affect pruning
gonadal
what are the types of neurotransmitters
biogenic amines
amino acids
neuropeptides
what are the biogenic amines
dopamine, norepinephrine, epinephrine, serotonin, acetylcholine
what are the amino acids
glutamate, GABA, glycine, aspartate
what are the neuropeptides
somatostatin, substance P, oxytocin, vasopressin, prolactin, TRH, GnRH, CGRP
what are the 4 dopaminergic pathways
nigrostriatal
mesolimbic
mesocortical
tuberoinfundibular
nigrostriatal pathway is associated with
extrapyramidal motor system
mesolimbic pathway is associated with
arousal, memory, motivational behavior
mesocortical pathway is associated with
cognition, executive function, stress
TUBEROINFUNDIBULAR PATHWAY IS ASSOCIATED WITH
prolactin secretion
norepinephrine projections produce ____
excitation, arousal
norepinephrine is part of the _____ system
reticular activating system
where are the cell bodies of the norepinephrine neurons located
locus coeruleus
where are the cell bodies of the 5HT neurons located
a chain of raphe nuclei along the brainstem
5HT are involved in ___
regulation of mood, depression, obsessions & compulsions, social interactions/aggressiveness
dopamine and norepinephrine are ____
catecholamines
steps in catecholamine biosynthesis
L-tyrosine
L-dopa
dopamine
norepinephrine
epinephrine
L-tyrosine to L-dopa (enzyme?)
tyrosine hydroxylase
L-dopa to dopamine (enzyme?)
dopamine decarboxylase
Dopamine to norepinephrine (enzyme?)
dopamine beta hydroxylase
norepinephrine to epinephrine (enzyme?)
phenylethanolamine-N-methyltransferase
serotonin is an ____
indolamine
ACh is the primary neurotransmitter of ____
alpha motor neurons
ACh plays a role in __
wakefulness, attention, learning, memory
what is the rate-limiting step in ACh production
the reuptake of choline at the synapse
glutamate is the primary _____ neurotransmitter in the brain
excitatory
GABA is the primary _______ neurotransmitter in the brain
inhibitory
major types of neurotransmitter receptors
ionotropic
metabotropic
ionotropic receptors
form ion channel
activation alters membrane conductance
metabotropic receptors
act through G-proteins
can activate or inhibit second messenger systems
can also be associated with an ion channel
main groups of dopamine receptors
D1 like (D1, D5)
D2 like (D2-4)
D1 like receptors are coupled to
Gs
D1 like receptors stimulate __
adenylyl cyclase
D2 like receptors are coupled to
Gi/o
D2 like receptors actions
inhibit adenylyl cyclase, increase K+ conductance, decrease Ca++ conductance
serotonin receptor families
5HT1
5HT2
5HT4-7
the serotonin receptors are what type of receptor
metabotropic (G protein-coupled)
how do 5HT3 receptors differ
they are ionotropic
5HT1: type
Gi/o protein coupled
5HT1: cellular mechanism
decrease cellular levels of cAMP
5HT1: effect
inhibitory
5HT2: effect
Gq/11 protein coupled
5HT2: cellular mechanism
increasing cellular levels of IP3 and DAG
5HT2: effect
excitatory
5HT3: type
ligand-gated Na+ and K+ cation channel
5HT3: cellular mechanism
depolarizing plasma membrane
5HT3: effect
excitatory
mechanisms of neurotransmitter termination
uptake, degradation
basic mechanisms of neurotransmitter uptake
taken up & re-packaged
broken down, byproducts taken for re-use
taken up by glial cells, converted, re-used
SSRIs basic mechanism
enhance serotonin activity at receptors by blocking serotonin reuptake
TCAs basic mechanism
enhance activity of monoamines by inhibiting reuptake of norepinephrine and in some cases serotonin. also affects ACh and other biogenic amines
adderall, methylphenidate mechanism
increases dopamine and norepinephrine activity by blocking uptake into presynaptic vesicles & increasing neurotransmitter release (Adderall) or by blocking dopamine reuptake (MPH)
MAOIs mechanism
enhance activity of DA, NE, and 5HT by inhibiting monoamine oxidase, thereby preventing degradation of the NTs
cholinesterase inhibitor drugs
donepezil, galatamine, rivastigmine
cholinesterase inhibitor mechanism
increase cholinergic activity in hippocampus and cerebral cortex (by inhibiting acetylcholinesterase)
sinemet contains
L-dopa and carbidopa
sinemet mechanism
enhances dopamine production in the brain
first generation antipsychotics mechanism
decrease dopamine activity by blocking D2 dopamine receptors
second generation antipsychotics mechanism
decrease serotonin and dopamine activity by blocking 5HT2a receptors, and to a lesser degree D2 dopamine receptors
ropinerole mechanism
agonist at D2 dopamine receptors
benztropine mechanism
partially blocks muscarinic cholinergic receptors in the caudate/putamen. also has ability to block dopamine reuptake
drugs that block reuptake
SSRIs
SNRIs
NDRIs
TCAs
adderall & methylphenidate
drugs that block degradation
MAOIs
cholinesterase inhibitors (donepezil, rivastigmine, galatamine)
drugs that increase neurotransmitter production
sinemet (L-dopa and carbidopa)
drugs that act as direct agonists or antagonists
FGAs
SGAs
Ropinerole
Benztropine
ropinerole is a _____
partial D2 agonist (parkinson’s)
benztropine works by ___
partial blocker of muscarinic cholinergic receptors
& blocks DA reuptake
serotonin biosynthesis
tryptophan–> 5-hydroxytryptophan–> serotonin (then gets broken down to melatonin)
enzyme: tryptophan–> 5-hydroxytryptophan
tryptophan hydroxylase
enzyme: 5-hydroxytryptophan–> serotonin
aromatic amino acid decarboxylase
enzyme: choline–> acetylcholine
choline acetyltransferase
enzyme that breaks down acetylcholine
acetylcholinesterase
