Unit 2 lecture Flashcards
history
- Know what the message is without having to hear it
- Caller ID and see it’s your boyfriend
- Dont listen to the message b/c you know what he wants based on history
- dese anteriorgrade amnesia
*
pathway
- result of neuromigration during development
history (science explanation)
- neurosculpting
- start with undifferentiated neurons and then figure out who you are by wiring specific neurons
neural wiring
- dedicated pathways and history
zygote
single cell (sperm+egg)
embryo
- 2 or more cells
- totipotent
stem cell
- have the potential to differentiate into any cell
- regenerate
totipotent
- ability of single cell to divide and produce all the differentiated cells that make up an organism
In vitro fertilization (IVF)
- inject fertilized egg into female that is infertile, or whose husband is infertile
- implant multiple to be sure
how does totipotent cell know what to differentiate into
- chemical gradient in uterus
- chemical composition of cell in uterus, determines what it will become
- nearest to bottom- neurons (fetus develops with head down)
migration
- neron has to migrate to target in spine
- genetics and chemical influences determine migration during development
difference between fetus and embryo
- fetus at 3 months b/c start looking human
how does neuron know where to travel
- growth cone serves as “feelers”
retina neurons
- half of cell cross over at ptic chiasm
- other half dont
- example of some neurons following signs and others not
3 stages of differentiation
- figure out what cell is going to be
- strat to migrate
- when close to target get permiscuous about where you want to be
Retinal signal
- neural cell in retina senses light
- nerve reaches optic chiasm
- cells then travel to cortex
- *spot on retina correlates with spot on cortex (good connection)
bad connection
- signal on retina goes to wrong part of cortex
- surrounding cells in retina are correct connection and behaving appropriately- releasing neruotransmitters and neurotrophins
- surrounding cells in cortex are not happy b/c not in the same location as the right cells
- neural cell of bad connection goes through apoptosis
neurotrophins
- enhance growth
- Ex: nerve growth factors
apoptosis
- programmed cell death
- cell only does it when it knows it doesn’t belong
- leads to the complicated connections and proper cell arrangement
- Ex: good for eliminating webbed feet and hands of embryo
- bag organnelles to prepare for release upon bursting and macrophage degradation
necrosis
- cell injury that results in premature death
- membrane ruptures and dumps organelles into extracellular fluid before they are “bagged”
- release of free radicals
- Inflammation
connect to right side of cortex
- turn on and off at the same time as neighbors
- release and receive neurotransmitters and nerve growth factors at same time as others
- If iincorrect, don’t do or get stuff at same time as neighbors, so go through apoptosis
Japanese and “r” and “l”
- during development that can distiguish rs and ls
- as adults can’t hear or say rs and ls differently
- examples of apoptosis
Canadians vs. Americans
- Americans have lost ability to hear 3 different sounds, but Canadians can
- Ex: can’t distiguish between about and a boot
learning language
- many connections before age 5
- connections decrease after 5 b/c cells that aren’t used kill off
- loose ability to distinguish
- Ex: why easier for younger kids to pick up numerous languages
Genie
- when made noises she was beaten
- when found only spoke 2 english words b/c dad and mom didn’t talk to her (just yelled)
- shows that we have an INNATE tendency to pick up language
- IQ was above average, but was still unable to pick up language
critical period
- period at which language cortex kills itself after you haven’t picked up a language
- Genie was 13, so must be before 13
trying on different hats
- during adolescence try different identities
- whatever you practice at end of adolecence remains, while other cells associated with other things that don’t fit
- pick your rut well
frontal cortex
identity
cigarette companies
- want to recruit adolescence b/c they will kill off cells that don’t encourage smoking
- stuck with additcted cells
what happens to a developing neuron that fails to reach its target
- would be outlier and not truning on and off simultaneously with surrounding neurons
- commit apoptosis- genetic tendency
how does neuron find its target
chemicals
why don’t most neurons regenerate
- connections are very numerous and complicated
- no longer have chemical gradient to follow
- BBB isolates neurons from chemical and pathogenic insults- no exposure means don’t really need to
why do olfactory neurons regenerate
- they are stem cells (other neurons aren’t)
- connections are simple
- they are not isolated by BBB
- exposed to chemical insults for your benefit and protection
- olfatory neurons have to test for us
what are 3 epochos characterized by massive apoptosis
- ) prenatal- before birth
- ) paranatal- after birth
- ) age 21- find identity then other connections not used die
what happens if inject NGF (nerve growth factor) antagonist into developing brain
- massive widespread brain damage
- none of the cells think they are connected in the right way
- in a normal cell, only the nerves that think they are not normally connected kill themselves
turpsichore
- goddess of dance
- chorea from Huntington’s chorea
Huntington’s chorea
- dominant and lethal
- lose inhibitory -> everything you do is excitatory
- always overshoot destination
incest
- bad for genome to have sex with close relation
- may express lethal genes that could have been avoided by having sex with someone who wasn’t related
- if both heteroygous, 1/4 chance of having a kid with lethal genes
homozygous for dominant w/ heterozygous for lethal
- no kids express double recessive lethal version
Hapsberg
- kept mating with each other so more and more prominant jaw
mutations
- maladaptive
- lethal
- most often recessive
arranged marriage where you meet on wedding night
- more successful
preventing recessive expression
- repeled from people you don’t want to have sex with (close relatives, friends)
- genes don’t want to have sex with closely related
arranged marriage with childhood acquaintance
- less successful b/c genes don’t like to have sex with closely related
combination of excitatory and inhibitory
- essential for every move you make
- don’t get to destination as fast, but get there effectively and don’t overshoot (as would if only excitatory)
only have excitatory movements
- consequence of drinking b/c alcohol suppresses inhibitory senses
- cells don’t repolarize
- overshoot destination
- ex: swining door- spring only
door w/o spring and shock absorber
- spring- excitatory
- shock absorber- inhibitory
- stimulates motor neurons
how can lethal gene be dominant
- lethal at onset
- lethal genes passed on to kids
Parkinson’s disease
- dopaminergic cells in substantia nigra fail to release dopamine -> can’t move
- loss of dopaminergic cells
- typical onset after 45 years old
- movement can be initiated by external influences
parkinson’s and movement
- can’t initiate movement on your own- internally
- externally- initiated actions are possible though
- Ex: once complete first step, can go up all of them
MPTP
- injection similar to heroin
- one guy became paralyzed in rigid state- heroin paralysis is sloppy, not rigid
- targets dopamine reuptake transporters
- representation of what occurs with parkinson’s
addictive drug
- targets dopamine
- cocaine, alcohol, heroin, etc
- Marijuana and LSD NOT addictive
dopamine action
- ) dopamine release
- ) dopamine transporter release
- ) dopamine & transporter to soma
- ) in soma dopamine removed and recycled (repackaged)
blocking dopamine transferase
- caused by MPTP in synapse
- affinity of MPTP and dopamine transporter molecule is much greater than transporter affinity for dopamine
MPTP and dopamine transporter
- high affinity
- blocks up mitochondria
- cell can’t function w/o mitochondria
- dopaminergic cell dies
treat parkinson’s
- L-dopa
- stem cells
L-dopa
- can cross blood brain barrier, unlike straight up dopamine
- dopamine “bisquick”
- remaining dopaminergic cells can use to make dopamine effectively w/o having to start from scratch
- temporary treatment for parkinson’s b/c dopaminergic cells will continue to die
reason for reduced prevealence of Huntington’s
- gene testing lets person know they have the lethal gene and could pass it on
- most people won’t have kids and take risk
will we all develop parkinson’s
yes b/c dopaminergic cells die off over time
negative symptoms of schizophrenia (SZ)
- lacking something normal people have
- flat affect
- catatonia
- waxy flexibility
substantia nigra
- part of midbrain that plays a role in reward, addiction, and movement
- death of dopaminergic neurons leads to Parkinson’s
dopamine and substantia nigra
- loss of dopaminergic neurons in substantia nigra results in Parkinson’s
schizophrenia
- mental disorder characterized by a breakdown of thought processes and deficit of typical emotions
- Eugen Bleuler defined as split-mind
- NOT multiple personality disorder
diagnosing sz
- negative and positive symptoms
positive symptoms sz
- have something extra that normal people don’t have
- NOT such a good thing
- psychotic cluster
- disorganized cluster
affect
expression of feeling or emotion
psychotic cluster
- positive symptom sz
- generally expressed by age 30
- hallucinations- generally auditory
- delusions
- paranoia