Exam #1 Flashcards
What is the Neuron Doctrine?
- Neural Units: Neurons are individual cells with specialized compartments.
- Synaptic Contact: Neurons are non-continuous and contact each other at synapses.
- Dynamic Polarization: Neurons transmissions tends to be unidirectional.
Describe landmark findings that suggest function is localized within the brain?
Wernickes Area: Understanding language.
Brocas Area: speech
What did Cajal contribute?
2) Cajal: suggests neurons communicated by specialized junctions called synapse. Won!
What did Golgi contribute?
3) Golgi: suggests the brain is composed of a physically connected reticular network through which neurons communicate.
- Won nobel peace prize in recognition of their work on the structure of nervous sytem.
Why is Wilder Penfield considered the father of modern Neuroscience? What and where were the two homunculi that he discovered?
He worked in epileptic patients to develop map of the sensory and motor cortex. Sensory(Lips, hands, feet and sex organs) and Motor(Size).
What is optogenetics, and how does it let us ‘take control of the brain?
It is controlling the brain with a small blue light(rhodopsin) that controls neurons. It targeted into a single neuron type and inserting it into the genome of a mouse. When you shine the light into the mouses brain, the channel rhodopsin responds, and the neurons that are now expressing the channel rhodopsin fire.
Who was H.M.? What could he remember? What could he not remember? Which area of his brain was damaged?
Henry Molaison who suffered from epileptic seizure. He had an operation and had his hippocampus removed and had his memory removed and reduced the seizures. He lost an 11 year period of memory before his surgery. Could remember his childhood but not little fragments. Could not remember anything going forward. He forgot almost in an instance.
Describe the experiment and name the researcher that first demonstrated synaptic transmission.
Otto Loewi extracted a frog heart with a vagal nerve intact for innervation and kept the heart beating in solution. Stimulating the nerve slowed the beating of the heart. After stimulation, he applied the solution from the innervated heart to a second isolated heart (no nerve); he observed a slowing in the beating of the isolated heart. This showed that stimulation of the vagal nerve released a chemical into the solution of the innervated heart, which was able to cause a chemically mediated response in the second (isolated) heart
What are the primary functions of the dendrite, soma and axon.
Dendrite: Collects electrical signals. Soma: integrates incoming signals and generates outgoing signal to axon. Axon: Passes electrical signals to dendrites of another cell or to an effector cell.
How do the ions Na+, K+ and Ca2+ function in generating an action potential?
It starts at equilibrium and then Na+ influxes and the K+ effluxes and then it goes to equilibrium.
What is an action potential? How does it propogate through myelinated and unmyelinated regions?
Action potential: A brief pulse of electrical current that is generated by a neuron and may be transmitted to neighboring cells. Because of insulation provided by myelin, action potential can travel much faster down the myelinated axons. The action potential travels much slower in unmyelintaed axon since they lack myelin sheaths and are short.
Describe an action potential. Why is it self regenerating and all or none. Where does it propagate from? What does it induce once it reaches the synapse. -
Self regenerating, all or none change in voltage, propagates from axon hillock (cell body), and induces synaptic transmission. It is self regenerating because it is depolarizing currents established by the influx of Na flow down the axon and trigger an action potential at the next segment.
Define different levels of analysis for studying brain function.
System(central nervous system: brain and spinal cord), Organ (the brain: collection of tissue controls functions of body), Tissue (Nuclei: group of neurons and perform functions), Network: neurons and connections between them, Cell (Neurons: transmit electrical signals, process data and communicate with eachother via synapse.) and molecules: smallest unit containing 2 or more atoms.
How is sensory information to and from the head conveyed?
Cranial nerves process info to and from head. Neural circuits within the brain process sensory information.
Describe three methods of removing neurotransmitter from the synapse. Can you name a drug that impacts one of these ?
Diffusion: away from synapse. Reuptake: Neurotransmitters re-enters presynaptic axon terminal. Enzymatic: destruction inside terminal cytosol or synaptic cleft.
SSRIs block serotonin reuptake
