psychopharm & brain structures Flashcards
neuron loss and place of regeneration
less than 2% by age 70
hippocampus, caudate nucleus
conduction
messages within a neuron are transmitted from dendrites to the end of its axon
action potential
electrical impulse that travels quickly through the cell
depolarization (interior of cell becomes less negative) is followed by repolarization (positively charged potassium ions to leave)
all or none principle
whenever the stimulation received by a neuron exceeds a given threshold, the resulting action potential will always be the same intensity
synaptic transmission
transmission of information from one nerve cell to another is chemically mediated
release of neurotransmitter to synaptic cleft
neurotransmitters
chemicals that transmit signals from one neuron to another
Acetylcholine
found in peripheral and central nervous systems
peripheral: causes muscles to contract (Myasthenia gravis)
CNS: REM sleep, sleep-wake cycle, learning and memory (Alzheimers)
Dopamine
catecholamines
Schizophrenia (too much)
Tourette’s (too much in caudate nucleus)
Parkinsons (not enough in substantia nivea
stimulant drugs, opiates, alcohol, nicotine
Norepinephrine
catecholamine
mood, attention, dreaming, learning, autonomic functions
low mood (catecholamine hypothesis)
Serotonin
inhibitory effect
mood, hunger, temperature, sex, arousal, sleep, aggression, migraine headache
too much: Schizophrenia, ASD, Anorexia
too little: aggression, depression, suicide, Bulimia, PTSD, OCD
GABA
inhibitory
eating, seizure, anxiety, motor, vision, sleep
too little: anxiety, (benzos enhance GABA), Huntingtons
Glutamate
excitatory
learning and memory (long term memory)
too much: seizures, stroke brain damage, Huntington’s, Alzheimers, neurodegenerative disorders
Endorphins
endogenous opioids, analgesic properties
spinal cord
made of bundles of myelinated axons, dendrites, cell bodies, interneurons;
1) carries info from brain and peripheral nervous system
2) coordinates left and right side
3) simple reflexes
superior (dorsal): carry sensory (afferent messages)
inferior (ventral): transmit motor (efferent) messages
quadriplegia
damage at cervical level
loss of sensory and voluntary motor function in arms and legs
paraplegia
damage at thoracic level
loss of sensory and voluntary functioning in legs
hydrocephalus
obstruction of the flow of CSF - > build up of fluid and enlargement of ventricles
somatic nervous system
(part of peripheral NS)
sensory nerves that carry info from body’s sense receptors to the CNS and motor nerves that carry info from the CNS to the skeletal muscles
governs voluntary activities
autonomic nervous system
(part of peripheral NS)
sensory nerves and motor nerves
mostly involuntary activities
sympathetic branch
arousal and expenditure of energy
fight or flight
parasympathetic branch
conservation of energy
rest and digest
meditation, hypnosis, biofeedback - activate parasympathetic branch
development of CNS (5 stages)
proliferation - embryo 2 1/2 weeks old. new cells in neural tubing
migration - 8 weeks - immature neurons go to their destination and begin to form brain structures
differentiation - develop axons and dendrites
myelination - insulating sheath (postnatally)
synaptogenesis - postnatally - influenced by genetic and experiential factors
CT and MRI
structural techniques -
MRI slightly preferable
PET and fMRI
functional techniques - brain activity (blood flow, glucose, metabolism, oxygen consumptio)
Hindbrain
medulla and pons
cerebellum
medulla
influences flow of info bt spinal cord and brain
swallowing, coughing, sneezing
vital functions: breathing, heartbeat, blood pressure
pons
connects 2 halves of cerebellum
integration of movements in R and L side
cerebellum
balance and posture (along with: basal ganglia and motor cortex)
timing and coordination of motor activities
shift attention
autism, schizophrenia, ADHD
ataxia
damage to cerebellum
slurred speech, severe tremors, loss of balance (similar to bx in alcohol intoxication)
mid brain
superior and inferior colliculi, substancea nivea, reticular formation
reticular activating system (RAS)
part of reticular formation
consciousness, arousal, wakefulness
damage disrupts sleep wake, can produce coma like state of sleep
some anesthetics work here
Forebrain
thalamus, hypothalamus, basal ganglia, limbic system
thalamus
“relay station” for sensory info except for olfaction
Wernicke Korsakoff syndrome
thiamine deficiency - causes atrophy of neurons in thalamus (result of chronic alcoholism)
starts w Wernicke’s encephalopathy - mental confusion, abnormal eye movements, ataxia
hypothalamus
hunger, thirst, sex, sleep, body temperature, movement, emotional reactions (laughter or rage)
maintains homeostasis through ANS, pituitary, and endocrine glands
suprachiasmic nucleus
in hypothalamus
sleep-wake cycle, circadian rhythms
seasonal affective disorder
basal ganglia
3 forebrain structures: caudate nucleus, putamen, globus pallidus, and then substantia nigra (in mid brain)
planning, organizing, voluntary movement, motor actions
sensorimotor learning
stereotyped motor expressions of emo (smiling)
Huntington’s, Parkinson’s, Tourette’s, OCD, ADHD
Limbic system
memory and emotion
amygdala, hippocampus, cingulate cortex
amygdala
motivational and emotional activities - attaching emotions to memories, involved in recall of emotionally charged experiences
flashbulb memories
Kluver-Bucy syndrome
lesions in amygdala and temporal lobes of primates - reduce fear and aggression, increase docility, hyper sexuality, psychic blindness (can’t recognize meaning of events)
hippocampus
less about emotions; learning and memory
spatial, visual, verbal info and consolidating declarative memories (ST to LT)
formation of visual images
corpus callosum
allows info bt hemispheres
contralateral representation
L hemisphere controls R side functions, etc.
olfaction is exception
brain lateralization
hemispheric specialization
apparent at birth
frontal lobe
primary motor cortex, supplementary motor cortex, premotor cortex, broca’s area, prefrontal cortex
prefrontal cortex
emotion, memory, attention, self-awareness, higher-order executive functions
Schizophrenia, ADHD, dementia
dorsolateral damage - impaired judgment, insight, planning
orbitofrontal damage - pseudopsychoapthy - emotional lability, distractibility, poor impulse control, impaired social insight
mediofrontal damage - pseudo depression - impaired spontaneity, reduced emotional reactions- no vegetative symptoms, no negative conditions, no dysphoria
parietal lobe
somatosensory cortex - pressure, temperature, pain
damage = apraxia (motor), somatosensory agnosia, anosognosia
Gerstmann’s syndrome
finger agnosia, R L confusion, graphic, acalculia
temporal lobe
auditory cortex and Wernicke’s area
encoding, retrieval, and storage of LT declarative memories
occipital lobe
visual cortex
visual perception, recognition, and memory
prosopagnosia - face blindness
