psych110 exam 2

what is neurodevelopment?

the development of the nervous system (how axons find their end targets), most specific the development of the cns

how does the cns begin?

the cns begins as development goes on and it begins to form pockets and folds which eventually become the brain we know

how do we start off as?

a single cell aka fertilized egg

from a single cell (fertilized egg), what is it transformed into?

divides to a double the number of cells

what are the early stage of cells called?

pluripotent, meaning they can become any cell type in the body

what are stem cells often referred to?

referred to as embryonic stem cells

what do stem cells divide or develop into?

into adult cells

whats neurulation?

the creation of the neural tube (and neural crest) happens approximately 24 days after conception

whats the rebound effect?

adaptation in the rate of firing

where do progenitor cells come out of?

stem cells that line the inside of the neural tube that give rise to the cells of the CNS

how does the neural tube form at first?

post gastrulation, the ectoderm consists of a neural plate surrounded by tissue that will become the epidermis

what does the neural plate invaginates inward for?

to produce the neural groove

what happens to the neural tube at the dorsal end?

it undergoes closure adjacent of the epidermal tissue

what is differentiation?

the process by which structures become more complex and functionally specialized

whats neural profileration?

the creation of neurons

where is the prosencephalon located?

top part/fore brain

what does the prosencephalon separate into?

telencephalon and diencephalon (hypothalamus and thalamus together makeup the dicencephalon aka cerebral cortex)

what is the mesencephalon located?

midbrain (does not branch into secondary vesicles)

where is the rhombencephalon located into?

the hindbrain

where does the rhombencephalon differentiate into?

metencephalon and myelencephalon

what does progenitor cells go through in the ventricle zone?

symmetrical division that produces two new progenitor

what does the symmetrical division create?

the ventricular and subventricular zones (VZ and SVZ)

what begins after 7 weeks in cell division?

they divide into one progenitor cell & one brain cell

what are the first brain cells produced by?

asymmetrical division which are radial glia

where do radial glia extend fibers to?

VZ to the pia

what happens to the glia fibers as new layers are added to the cortex?

grow longer and longer

where do neurons migrate along?

radial glia to their place

what is tengential migration?

new cells push previously formed cells out of proliferation zone in the VZ or SVZ toward the place where they need to migrate

what is spatiotemporal gradient?

layering from the inside; usually true for inner structures such as the thalamus and hypothalamus

how does the cortex develop?

develops from the inside out where the first cells establish the deepest layer outside

where does the next wave of cells develop after the first cells establish in the deepest layer?

develop a layer outside

how do cells move to their places?

by neural migration (movement of neurons)

what occurs after layers are created to the radial glial cells go through?

apoptosis and are transformed into astrocytes

whats synaptogenesis?

neurons at their final location can begin to form connections with other neurons by growing axons and dendrites and creating synapses

whats apoptosis?

death of neurons

how long does the brian develop after birth?

25 years

what occurs in the infant brain up to the age of 5?

growth of synaptic connections and myelination of axons

what is synaptic pruning?

the elimination process of synapses through apoptosis (birth into late 20s )

what happens to the axon and dendrite when synapses dont recieve signals?

are eliminated, decay

how can neural wiring be accomplished for the adult brain for example?

learning can increase the size of the cortex related to that subject

whats neuralplasticity?

the ability of the nervous system to change activity in response to intrinsic or extrinsic stimuli by reorganizing its structure, functions, or connections

what is sensation?

simulation of nerves, detecting the stimuli from the environment, transduction, use of sensory organs 

what is perception?

how we interpret the sensory signals

what is transduction?

the process that turns light into a biological signal or the process of converting sensory stimuli into a signal

what happens through synapses?

transduction

what is a wavelength?

the distance between two peaks of light aka the length of color leads you to perceive different colors

whats amplitude?

the height of waves; brightness, the higher the peak the brighter it is

is the retina part of the brain?

yes

what is the job of the retina?

perceiving the light, but interpreting it so its easier to process

what are optic nerves?

axons exiting the eye connecting it with the brain

whats the iris?

muscles around the pupil that allow the eye to contract

what is the cornea?

serves as a lens, protect your eye and collect the light and channel it inward 

what is the fovea?

 point in the retina where light goes in straight

does the retina have a blindspot?

yes, its due to optic nerve coming out the eye

what is the last layer in the retina?

photoreceptors

what is the second layer in the retina?

bipolar cells

what is the first layer in the retina?

retinal ganglion cells

RGC is less what than photoreceptors?

less dense than photoreceptors

when are rods sensitive to light?

high sensitive light

when are cones sensitive to light?

low sensitive to light

where are rods located?

Around the fovea aka periphery (rare in the actual fovea)

what is not responsible for high acuity vision but responsible for low acuity vision?

rods

what are cones responsible for?

high acuity and low sensitivity to light and color sensitivity (RBG)

what do center ganglion cells respond to?

 respond to a bright spot on its center and also to a dark ring on its surround; activate if they perceive center of their visual field; deactivate in the center or light in the surround

what do off center ganglion cells respond to?

 respond to a dark spot on the center or bright light on the surround; activate if there's dark in the center, if there's light in the center (they activate), if there's dark in the surround, they activate; if there's light in the center, they deactivate. 

do both on center and off center ganglion cell responses occur simultaneously?

yes

what is the opponent process theory?

A theory that explains color vision in terms of opposing pairs of colors, such as red-green and blue-yellow, where stimulation of one color in a pair inhibits the other.

what colors do rods respond to?

black and white

what colors are in the human eye aka the trichromatic theory?

red blue and green

what occurs in sensory transduction?

The photoreceptor transduces the light into an electrical signal when it gets to the bipolar cells.

After that, it gets sent to the retinal ganglion cells (RGC). These cells send the signal to the brain through the optic nerve

what do photoreceptors or bipolar cells not have?

have axons

what is rhodopsin?

photo pigment that absorbs the electromagnetic radiation of light that causes change in retinal protein (vitamin A) and activates the opsin

opsin turns lighter when it is?

bleached with light (originally purple)

what do photoreceptors release?

releasing glutamate in the dark by photoreceptors

what is the dark current known as?

 releases glutamate in the dark by photoreceptors but once light hits, them they shut down and stop releasing glutamate.

when do photoreceptors depolarize?

when they detect darkness in the retina

when do photoreceptors hyper polarize?

when they detect light and stop glutamate release

how is light converted?

 converted into a change in membrane potential in the photoreceptors by photo pigments

what is the lateral geniculate nucleus?

a structure in the thalamus that relays visual information from the retina to the primary visual cortex in the brain; different aspects of a visual image

what is layer 1 and layer 2 in the LGN responsible for?

respond to movement and are achromatic

what are layers 3 and 6 sensitive to?

color sensitive and more sensitive to detail

RGC outside the retina project to what side of the brain?

ipsilateral (same)

RGCs from the inside of the retina project to?

contralateral (opposite)

what cortical module is responsible for input of one eye over the other?

ocular dominance columns

what are cortical modules?

hypothetical constructs but they have a physiological basis

each cortical module analyses different aspects of a?

visual stimulus

what cortical module analyzes the color of an object?

blobs

what cortical module analyzes the shape or form of an object?

orientation columns

all neurons in an orientation column respond to?

to a line of the same orientation

neurons in an adjacent orientation columns respond to?

to lines with a 10% difference

orientation column neurons have a?

receptive field, are elongated, and be on center or off center

orientation column neurons are most sensitive to?

bars that fill their center without impinging (have an impact) on the surround

what are the two pathways the extrastriate cortex have?

the what (ventral) pathway and the where/how (dorsal) pathway

what is the ventral pathway?

object recognition and object identification

what is the dorsal pathway? (how/where pathway)

location in space and how one might interact with a particular visual stimulus

what is an example of the ventral pathway (what pathway)?

we can differentiate between the faces and the objects and body parts very well

what is an example of the dorsal pathway (where pathway)?

some brain areas respond better to moving stimulus

whats the inferior temporal cortex?

part of the ventral stream, involved in recognizing visual patterns, identifying objects

what is V1 in the inferior temporal cortex responsible for?

analysis of elementary aspects of information (color, shape, orientation, etc.)

what influences our perception?

brain interoperation of light signals so we all perceive the world differently