• process of neurotransmitter release
• requires calcium 
• synaptic vessels fuse with membrane

• diffuse
• deactivating enxymes take over
• reuptake

1. how does the brain function?

2. what things can go wrong in the brain?

3. can disease be prevented or cured?

• case studies
• experiments
• associate abnormal behavior with defecits in teh brain 
• observe brain's response to alterations in the environment and consequent changes in behavior

• through the sympathetic and parasympathetic nerves
• both are 2-stage neural paths - they only go part of the way to organs, then they are synapsed with other neurons 
• sensory information is gathered by afferent nerves and brought to the brain

Parasympathetic nerves

• all have to do with sensation and perception
• thalamus: auditory and visual function as well as the tectum
• cortex process all of this information 

• medial geniculate nucleus: responsible foer auditory function
• lateral geniculate nucleus: responsible for visual function

• the cerebellum
• the pons

(motor coordination)

leads to disturbances in:

• fine motor control
•  coordination 
• posture

• Caudate nucleus
• putamen
• globus pallidus

CPG

• long tail-like structures
• sweep out of the amygdala almost making a complete circle
• connected to the putamen

• ventral horns of the spinal cord
• important component of sensorimotor system
• movement

• maintaining a stable constant condition
• resitance to change

• septum
• hippocampus
• amygdala
• cingulate cortex

SHAC

regulation of motivated behaviors:

• fleeing
• feeding
• fighting
• fornication

• thought
• voluntary movement
• language 
• reasoning
• perception

• parietal
• occipital
• frontal
• temporal

POFT

• Dura mater
• Arachnoid
• Pia Mater

DAP

• build up of CSF in the ventricular system 
• could cause damaging amounts of pressure 
• caused by the bloodstream not fully absorbing the fluid due to a damaged filter in the brain or the flow of fluid in the ventricles being blocked 
• can be treated with a shunt that will drain the excess fluid

• carotid artery 
• vertebral artery

• protect the brain from "foerign substances" in the blood that could injure the brain
• protects the brain from hormones and neurotransmitters in the body

• development (it isn't yet fully formed)
• injury/trauma
• hypertension (high blood pressure)
• microwaves

dorsal: carries sensory information to the brain

ventral: carries motor information to the body

• sensory
• motor 
• autonomic information

• dendrites
• cell body (soma)
• axon
• axon hillock
• axon terminals

• unipolar - cell body sits off to side, one transmittign channel
• bipolar - singular dendrite / axon
• multipolar - lots of dendritic branching

• oligdendrocytes
• astrocytes
• Schwann cells
• microglia

• passage of chemicals from blood to neurons, help to form BBB

extracellular

intracellular

outside of the cell - sodium

chloride

potassium channels close.

• absolute-stimulation cannot elicit another action potential because Na channels are still inactivated
• relative-stimulation can elicit another action potential but it is harder because the membrane is hyperpolarized, the resting volatage is below -70 (potassium)

ionotropic

metabotropic

• exocytosis
• release- as vesicles fuse, they spill their contents into the synapse
• binding - neurotransmitter binds to receptors on the postsynaptic membrane
• deactivation

ionotropic (fast)

metabotropic (slow but can have long term effects)

• a neurotransmitter binds to a receptor
• the receptor releases a G protein which binds to an ion channel
• this G protein causes the ion channel to open allowing ions to pass
• norepinephrine 

essentially: with the additional step of needing the extra G protein rather than 2 neurotransmitters, it makes this process slower in comparison to iontropic receptor processes

• glutamate
• aspartate
• GABA
• glycine

• catecholamines
• indolamines

highly branched axons found mostly in the brain, synthesized from a single amino acid

• dopamine
• epinephrine
• norepinephrine

all synthesized from the amino acid tyrosine

• serotonin - synthesized from the amino acid tryptophan 

Tyrosine > Dopa > Norepinephrine > Epinephrine

TDDNE

"Totally Dumb Dump New England"

• contrast x ray
• CT
• MRI

• PET
• fMRI
• diffusion tensor imaging
• TMS

measure of the gross electrical activity of thebrain

- can measure brain states and pathologies

change in EEG that is the result of a momentary stimulus 

ex: hearing - if an auditory stimulus is presented and there is no evoked potential, then a hearing impairment could be determined

• computer assisted x ray procedure
• used to visualize the brain and other internal living structures
• shows brain lesions
• shows cross-sectional brain images that are 3D

• first brain-imaging technique to provide images of brain activity 
• begins with a 2DG injection which will indicate what areas were most active during the 30 second scan 
• this identitfies brain molecules of interest i.e. neurotransmitters

• high resolution images are made from waves that hydrogen atoms emit when they are activated by radiofrequency waves
• essentially shows structure

• produces images representing the increase in oxygen flow in the blood to active areas of the brain 
• essentially demonstrating function

• a surgical device that allows a surgeon to precisely locate brain structures in 3D
• essentially a brain atlas

• electrical
• chemical
• reversible

• to assess the behavior in absence of the particular structure lesioned
• give inference to functions that could be associated with the lesioned element

• activate neurons in an area
• this is used to treat Parkinson's Disease (pace-maker-like device)

ex: "ratbot" - stimulating regions associated with different directions of the rats face in order to make them turn, then stimulating the rat's reward center to reinforce whatever behavior was directed

for: 

• health of humans 
• health of animals for vet practices
• evolutionary insights

against:

• animals are too different from humans
• all animals are living creatures and should be respected

• how can research results derived from animal testing be extrapolated to humans?
• what assurances exist that stolen or lost pets are not used in research?
• are the animals in laboratories suffering or in pain?
• what happens to animals ocne experiment is completed?

Institutional Animal Care Use Committee

• review concerns
• review/ approve modifications
• authorized to suspend any activity involving animals

• the ability to control the halting of administered shock

• 2 groups receiving tailshock from a source
• one group can terminate the shock
• one group receives same shock, but cannot terminate it 

• less fight/flight responsive
• more fear/anxiety responsive

• inhibitory presynaptic receptor that regulates the release of a neurotransmitter
• homeostatic mechanism

• executive control
• inhibits lower brain regions (cerebellum, initiates movement)
• emotional regulation

uncontrollability of the stressor

- presence of the ability to control inhibits neural responses to stressors

• intravenous
• inhalation
• absorption through mucous membrane

• lower tendency to cross the BBB, thus have more of an effect on histamine-producing systems in the brain 

• heroin crosses the BBB much more readily than morphine which makes it 3x as potent
• heroin = diacetyl morphine

• contributes/ produces hangovers
• toxic, has similar structure to formaldehyde

• inhibits enzyme that breaks down acetaldehyde, causing it to build up and increase negative side effects and symptoms 

• substantia nigra
• Ventral Tegmented Area (VTA)

levodopa: drug increases the synthesis of neurotransmitter molecules (increases the amount of precursor)

morphine: drugs binds to postsynaptic receptors and either activates them or increases the effect on them

nicotine and alcohol: inhibit serotonin synthesis, destroys synthesizing enzymes 

naloxone: drug is a receptor blocker; itbinds to the postsynaptic receptors and blocks the effect of the neurotransmitter

• progressively decreasing responsiveness to a drug
• more of the drug is needed to achieve the same effect

• metabolic tolerance
• functional tolerance (cellular and conditioned)
• cross tolerance
• sensitization (opposite of tolerance)

• adverse effects of discontinuing drug use
• oppose the effects of the drug used

• drowsy/ hypnotic
• constipation
• reduced respiration
• reduced heart rate

• insomnia 
• diarrhea
• increased respiratory/ depth
• icnreased heart rate (raised BP)

• stimulants
• depressants
• narcotics
• hallucinogens

• blocks the reuptake of dopamine, dopamine stays in the synapse longer
• works in the mesocorticolimic dopamine pathway
• the projectionsn from the VTA area to the nucleus accumbens play an important role in cocaine addiction

• central nervous system over-stimulation
• convulsions
• respiratory or cardiac arrest
• lethal dose is difficult to determine due to variability in individual responses
• toxic reactions could produce rapid death

• rats were allowed to give themselves electrical stimulation, called ICSS (intercranial self-stimulation)
• rats would press the adminstration lever thousands of times in an hour, suggesting a very powerful motivation for pressing
• brain sites supporting ICSS were those that normally mediated the pleasurable effects of natural rewards

• hypothalamus
• septum
• nucleus accumbens
• VTA (ventral tegmental area)

• repeated intake of drug in a distinctive environment
• dopamine agonists assist in reward, and they are released in this area due to drug use
• thus, the environment is associated with dopamine reward

• it is the "reward circuit"
• dopamine travels through projections from the VTA to the nucleus accumbens which then disperses it amongst the prefrontal cortex
• cocaine blocks reuptake of dopamine, so it floods the reward pathway thus making addiction a high risk
• those that are cocaine users have less dopamine receptors due to lack of use

• cerebral hemmorrhage
• obstructive strokes
• -cerebral ischemia
• -anteriosclerosis

blood accumulation puts pressure on brain tissue and damages it - this is caused by:

• hyptertension
• structural defects
• toxic chemicals
• blood diseases
• rupture of aneurysms

• administer drugs that dissolve blood-clots  and reestablish circulation
• neuroprotectants - protect the brain from excitotoxicity post-stroke
• physical therapy

• the brain is damaged due to compression (if severe could result in a subdural hematoma)
• damage produced by bleeding, tearing, and swelling

• rigidity
• resting tremor
• Bradykinesia: difficulty initiating movement
• Postural instability

autonomic (the sns) & fight/flight

behavioral

endocrine

• emotional blunting 
• hyperphagia(extreme weight gain)
• innappropriate sexual behavior 
• visul agnosia (inability to recognize objects)

• increased heart rate
• decreased appetite
• defecation
• decreased pain
• increased startle
• increased motor activity

the lateral and the basolateral amygdala. Where fear learning occurs. (input) 

associated with the pairing of conditioned and unconditioned stimuli

• corticotropin-releasing hormone-enhanced startle 
• light-enhanced startle
• learned helpnessness

mediates responding to long-duration stimuli that may have an element of unpredictability 

• they bind to different parts of the receptor and make the neurotransmitter better or worse at activating the receptor
• essentially it modulates the effectiveness of the neurotransmitter

• major depression
• dysthymia
• bipolar disorder

• MAOIs
• Trycyclic antidepressants 
• SSRIs

• all the catecholamines - epinephrine, norepinephrine, dopamine
• this also breaks down tyrosine - can't have cheese or beer

• in a study of rats, when this was lesioned circadian rhythms were destroyed
• receives input directly from retina
• transplants of this tissue in lesioned animals restores circadian rhythms 

• alpha (relaxed wakefulness)
• beta (alert, active thinking)
• theta (transition between sleep and wakefulness, stage 1 & 2 sleep)
• K-complexes (sudden sharp waves movements)
• Delta (stages 3 & 4)
• REM sleep

• areas of the brainstem
• parts of the preoptic area (VLPO)

• adenosine
• histamine
• orexin
• acetylcholine
• norepinephrine
• serotonin

• increase acetylcholine release, assists in waking
• projections from the histamine neurons in the hypothalamus to the cerebral cortex increase arousal

• project from thalamus t excite almost every part of the brain
• degernation of orexin neurons is associated with narcolepsy

regulating activity in the hippocampus (learning/memory)

increases cortical arousal

• SWS cold potentially remove free-radicals in the brain
• potentially consolidate learned material
• REM sleep could play a role in normal brain development
• sleep prevention has adverse effects on cognitive function and even physical functions

• repeated electrical stimulation of the neuron is necessary
• dependent on the acitvation of NDMA receptors
• in the hippocampus