Quiz 1 study guide PDF

Preview

Summary

study guide...

Description

Quiz 1 Study Guide 1. INTRO TO COGNITIVE NEUROSCIENCE ●

The evolution of thought about biological basis of mental processes

●

Phrenology, equipotentiality, neuron doctrine, functional specialization, layers of community organization (micro- vs. macrocircuits), anatomical vs. functional networks (from later lectures).

o

o

Phrenology ▪

o

equipotentiality ▪

o

the concept that the nervous system is made up of individual cells

functional specialization ▪

o

the theory that the brain has the capacity (in the case of injury) to transfer functional memory from the damaged portion of the brain to other undamaged portions of the brain.

neuron doctrine ▪

o

the detailed study of the shape and size of the cranium as a supposed indication of character and mental abilities.

a theory which suggests that different areas in the brain are specialized for different functions.

layers of community organization (micro- vs. macrocircuits) ▪

work A complex network made up of long distance connections between various brain regions. Neural networks are macrocircuits composed of multiple embedded microcircuits, and they support more complex analyses, integrating information processing from many microcircuits

▪

microcircute ▪

▪

Localized interconnected neurons form what is known as a microcircuit. Th ey process specifi c kinds of information and can accomplish sophisticated tasks such as processing sensory information, generating movements, and mediating learning and memory

macrocircute

1

▪

o

These long-distance connections between various brain regions connect to form more complex neural networks, which are microcircuits that are made up of multiple embedded microcircuits. Neural networks support more complex analyses, integrating information processing from many microcircuit

anatomical vs. functional networks (from later lectures)dis ▪

anatomical network is the highway and functional network is the traffic on the highway

2. NEUROPHYSIOLOGY ●

The main steps of synaptic transmission a.

The arrival of the action potential at the axon terminal leads to depolarization of the terminal membrane,

b.

causing voltage-gated Ca2+ channels to open.

c.

The opening of these channels triggers small vesicles containing neurotransmitter to fuse with the membrane at the synapse and release the transmitter into the synaptic cleft

d.

Diff erent neurons produce and release diff erent neurotransmitters, and some may release more than one type at a time, in what is called co-transmission.

The transmitter diffuses across the cleft and, on reaching the postsynaptic membrane, binds with specific receptors embedded in it What’s responsible for the postsynaptic potential? Excitation vs. inhibition, depolarization vs. hyperpolarization. a. a temporary change in the electric polarization of the membrane of a nerve cell (neuron). The result of chemical transmission of a nerve impulse at the synapse (neuronal junction), the postsynaptic potential can lead to the firing of a new impulse. The main compartments of a neuron, and the sequence through which a signal propagates through them. Concept of length constant. a. The distance over which membrane potential has dropped to 37% (i.e., 1/3) of initial value How’s the action potential generated? a. Action potentials are caused when different ions cross the neuron membrane. A stimulus first causes sodium channels to open. Because there are many more sodium ions on the outside, and the inside of the neuron is negative relative to the outside, sodium ions rush into the neuron. What ionic flow is responsible for it? e.

●

●

●

●

2

Ion transporters and ion channels are responsible for ionic movements across neuronal membranes. Transporters create ion concentration differences by actively transporting ions against their chemical gradients. How does it propagate? Why is it considered a digital signal? a. The magnetic field propagates through the layers of the scalp and skull, reaching the cortical surface below the coil and altering the electrical activity in the neurons; with a modest level of stimulation, the neurons briefly fire b. A digital signal is one in which a change in voltage, and the time at which it occurs, are of very much more importance than the precise size of the change or the exact shape of the waveform. How’s it different from the postsynaptic potential? a. post synaptic potential is temporary while digital signal can be long lasting Role of myelination a. speeds up things Cell membrane of neurons, potential difference across it, ionic composition in/out of the membrane. Why do neurons need energy, and how do they get it? a.

●

● ● ●

a.

Charged sodium, calcium and potassium atoms (or ions) are continuously passed through the membranes of cells, so that neurons can recharge to fire. ATP supplies the energy required for these ions to traverse cell membranes.

b.

Brain needs glucose as main source of energy but needs non-neuronal cells to consume the glucose and convert it to some intermediates for brain use.

3. NEUROANATOMY ●

Main organization of the nervous system

●

o PNS & CNS Anatomical nomenclature: dorsal/ventral, rostral/caudal, and medial/lateral views; sagittal/horizontal/coronal slices o lecture 3 Gyrus, o A protruding rounded surface of the cerebral cortex that one can see upon gross anatomical viewing of the intact brain. Compare sulcus. (Ch. 2) sulcus, o Also fissure. An invaginated region that appears as a cut or crease of the surface of the cerebral cortex. Compare gyrus. (Ch.2) fissure, o A fissure is a deeper grove and is often used interchangeably with sulcus. o the mariana trench of the brain bank,

●

fundus

●

●

●

●

o o

the part of a hollow organ 3

●

●

●

●

●

What’s gray and what’s white matter? Why white? o white matter (the axonal tracts) than in the gray matter (the cell bodies o The white matter of the CNS appears white because the majority of the nerve fibers in these regions are myelinated. Advantages of gyrification. o One advantage of gyrification is thought to be increased speed of brain cell communication, since cortical folds allow for cells to be closer to one other, requiring less time and energy to transmit neuronal electrical impulses, termed action potentials. Main lobes of cerebral cortex: names, location in the brain, and 1-2 key functions associated with them. o frontal lobe ▪ voluntary movement, expressive language and for managing higher level executive functions. o occipital lobe ▪ visual perception, including colour, form Glial…do we need them, really? (Hint: we do) o other subcortical structures. (Ch. 5) glial cell One of tw o cell ty pes (along with the neuron) in the nervous system. Glial cells are more numerous than neurons, by perhaps a factor of 10, and may account for more than half of the brain’s volume. Th ey ty pically do not conduct signals themselves; but without them, the functionality of neurons would be severely diminished. Tissue made of glial cells is termed glia. (Ch. 2) Major landmarks of the brain (gyri and sulci/fissures).

o

Corpus callosum: can we do anything without it? (Hint: Alan Alda video) o a large bundle of more than 200 million myelinated nerve fibers that connect the two brain hemispheres, permitting communication between the right and left sides of the brain. ● What’s Brodmann’s map and what was it based on? o • 52 areas, based on cell morphology, density, and layering ● What’s the deal with Penfield and his little humans? How did he relate to Brodmann? o topographical organization ● The visual system from retina to cortex, and what it means that there is a visual hierarchy. Dorsal vs. ventral streams. o ventral stream is specialized for object perception and recognition—for determining what we’re looking at. The dorsal stream is specialized for spatial perception—for determining where an object is—and for analyzing the spatial confi guration betw ee n diff erent objects in a scene. ●

4

o

●

●

●

● ●

Concepts of retinotopy, somatotopy, and tonotopy. o the mapping of visual input from the retina to neurons, particularly those neurons within the visual stream. 'retinal mapping' o the point-for-point correspondence of an area of the body to a specific point on the central nervous system o The spatial arrangement of where sound is perceived, transmitted, or received How do they relate to primary vs. secondary cortices? o The primary motor cortex (M1) lies along the precentral gyrus, and generates the signals that control the execution of movement. Secondary motor areas are involved in motor planning What does the size of the cortical area mean about the resolution of representation? o if it is large that means it is capable of receiving a lot of sensory input and a lot of receptor and if ti is smal than it is the opposit What are the main functions of the limbic system, basal ganglia, thalamus, cerebellum? Which are the major arteries that sustain the brain’s blood supply? How does Die Hard relate (or not) to them? How does the blood supply system relate to healthy brain function? o believe it's the circle of willis! like bruce willis from die hard haha

6...