Neurobiology 2, Brain Function Flashcards
What did Franz Joseph Gall suggest about the brain?
That the brain was divided into 27 separate “organs,” led to phrenology
Medulla and pons
control physical functions
Cerebellum
coordinates motor commands to muscles
Diencephalon
core of the “forebrain” and includes the thalamus, hippocampus, hypothalamus, and posterior pituitary
Telencephalon (cerebrum)
consists of two cerebral hemispheres (left and right)
-In humans, it is the largest part of the brain and plays major roles in sensory perception, learning, memory, and conscious behavior
Cerebral cortex
Higher-order information processing, diff regions of the cerebral cortex have specific functions, long-term memory
-ex: temporal lobes are involved in the recognition, identification, and naming of objects > damage to temporal lobe results in disorders in which the individual is aware of a stimulus but cannot identify it
Motor cortex
axons project to muscles in specific parts of the body, areas w/ fine motor control have greatest representation
Somatosensory cortex
receives touch and pressure info, whole body surface can be mapped onto somatosensory cortex
An example of neural plasticity
each finger has a specific location on the sensory and motor regions of the cortex; in monkeys, one middle finger was amputated and over time, the area of the cortex that had been dedicated to the middle finger was re-assigned to other fingers
Pathway of repeating a spoken word
brain activity travels from auditory cortex to Wernicke’s area to Broca’s area to motor cortex
Pathway of repeating a written word
brain activity travels from visual cortex to Wernicke’s area to Broca’s to motor cortex
What is aphasia?
an impairment of the ability to produce and/or comprehend language due to brain damage
Damage to Broca’s Area
unable to create gramatically-complex sentences, speech is telegraphic and choppy, patients are usually aware that they cannot speak properly
Damage to Wernicke’s Area
damage to posterior regions of left hemisphere, results in a more pronounced comprehension impairment, speech is normal but does not make sense (roundabout, vague, or meaningless)
What is the corpus callosum?
a major neural “highway” of axons that allows neurons on the left and right sides of the cortex to communicate
How does learning involve changes at synapses?
Repeated firing facilitates a synapse so that subsequent action potentials arriving at the same synapse release more NT vesicles than did the first action potential, increasing the probability that the later EPSPs will be more likely to elicit an action potential in the post-synaptic cell
Classical conditioning
involves associations between parallel synaptic pathways so that when one pathway is triggered the other one is too
Alzheimer’s Disease
a loss of synapses
What do learning-associated changes at synapses involve?
- changes in recruitment of receptors to postsynaptic membranes
- phosphorylation of proteins that modulate the amt of NT release or receptors which changes their sensitivity
What is an example of learning-associated changes at synapses?
Long-term potentiation at glutamatergic synapses (strengthens synaptic transmission)
How does LTP at glutamatergic synapses function?
- continued use of glutamatergic synapse
- recruit new receptors (AMPA)
- glutamate release activates AMPA receptors
- this triggers depolarization
- NMDA receptors are unblocked
- AMPA and NMDA receptors allow Na+ and Ca2+ influx that trigger bursts of action potentials
Hippocampus
short-term memory, plays a partial role in FORMING long-term memory
Tetrodotoxin on the Nervous System
potent inhibitor of voltage-gated Na+ channels (action potential stop)
Effect of novocaine and lidocaine
stop action potentials and act locally
Multiple Sclerosis
an autoimmune disease in which the myelin sheaths are attacked by the immune system, decreasing the efficiency at which signals travel
Symptoms: numbness, poor coordination, poor vision, and paralysis
Parkinson’s Disease
common neurodegenerative disease in which there is progressive degeneration of dopamine-containing neurons in a part of the brain (substantia nigra)
Symptoms: tremor, muscle rigidity and weakness, speech difficulties, dementia, and blank/mask-like facial expression
Treatment for Parkinson’s
Using L-dopa, a precursor to dopamine, or dopamine agonists to boost dopamine production
Depression
diminished interest or pleasure in activities, significant weight loss or gain unrelated to dieting, insomnia, hypersomia, fatigue, feelings of worthlessness or guilt, diminished ability to concentrate, recurrent thought of death
Is serotonin involved in depression?
-SSRI = selective serotonin reuptake inhibitors
-they inhibit serotonin reuptake to increase the time that serotonin lingers in the synaptic cleft after release
Schizophrenia
-related to dopamine and glutamate
-some drugs block a specific type of dopamine receptor
-Symptoms: hearing internal voices not heard by others; believing that other people are reading their minds, controlling their thoughts, or plotting to harm them
-Amphetamine can produce similar symptoms
Psychoactive drugs
- Cocaine
- LSD
- Amphetamines
Cocaine
inhibits dopamine and norephinephrine transporters
LSD
serotonin agonist
Amphetamines
induces release of dopamine and inhibits transporter; produces symptoms very similar to those of schizophrenia
What happens during meditation, prayer, chanting, and liturgies?
-increases activity in the front part of the brain and decreases activity in the area of the brain that orients our bodies in space
-decreased activity in orientation area is believed to be related to the changes in spatial recognition and the loss of self-awareness that’s associated with meditative states
-orientation area > parietal lobe
