When does the human central nervous system begin to form when in the embryo
2 weeks old
What does the fluid filled cavity become?
The central canal and the four ventricles
what does the neural tube form into?
the hindbrain, midbrain, forebrain
brain weight birth, 1, adult
350g, 1000g, 1400g
Production of new cells; cells along the ventricles of the brain divide to become neurons and glia
Movement of primitvie neurons and gila toward their final destination in the brain
Neurons developing an axon and dendrites; the axon grows before the dendrites while the neuron is migration toward its destination
Glia cells produce myelin forms first in the spinal cord before forming in the brain. Myelination begins during the prenatal period and continues into adulthood.
The final stage of neural development and refers to the formation of the synapses between neurons.
Who discovered that muscles produce and release nerve growth factor which promotes survival and growth of axons. Axon and cell bodies die without it. The muscles that synapse with the axons does not determine how many but which synapse survive.
Rita Levi Montalcini
When an axon and cell body dies without NGF its called
A chemical that promotes the survival and acitvity of neurons like ngf and brain-derived neurotropic factor (bdnf)
In what 3 ways does neurotrophins work?
increase axonal brainching
increase pain and increase regrowth of axon
What cells can replace ones that have died
Olfactory recptors, stem cells
Who severed optic nerve axons tectum: depends on chemical gradient in the target cells
During development, synapses form randomly before a selection process keeps some and rejects others in addition to chemical guidance and trophic factors
Because of the unpredictability of life, we have evolved the ability to ...
redesign our brain in response to experience
Environmental enrichment leads to...
enhanced dendritic branching and improved performance in animals and humans. The enrichment is bigger if they occur early in life
Can adult certebrate brain develop new neurons. Learning new things in for year strengthens dendritic spines.
Musicians have a larger what and thicker what
30% larger right hemisphere and left temporal lobe. Thicker gray matter where hand control and vision
A condition where the reorganizaiton of the brain goes to far. Clumsy, fatigue, involuntary movements.
Focal hand dystonia
Development of brain area depends on:
the rate of production of new neurons/day, and the number of days
What causes slight decrease in IQ scores, and greater decrease in language skills
What drug causes heart problems when exposed to a forming baby
What causes low birth weight, sudden infant death deficits, ADHD, impaired immune system, delinquency?
prenatal exposure to cigarette smoking
How does does a stroke destroy neurons ?
K accumulation and edema-the release of glutamate. Cells in vicinity die immediately.
Five most common stroke symptoms:
numbness or weakness of face, leg, arm, on one side.
sudden confusion, trouble speaking
sudden trouble seeing in on or both eyes
sudden trouble walking, dizziness
sudden severe headache
Tissue plasminogen activator activates the factor in the blood which ultimately break up a blood clot. To be effective, thrombolytic therapy should be administered as quickly as possible.
Glutamate antagonists, calcium antagonists, opiate antogonists and antioxidants. (cool the brain)
what has been known to potentially minimize cell loss after a brain stroke, most likely due to anti-inflammatory effects.
Removing the sensory nerves, forces to use the deafferented limb
Decreased activity of surving neurons after other neurons are destroyed. Behavioral deficits due to this can sometimes be improved with the use of use of stimulant drugs.
A newly formed branch from an uninjured axon that attaches to a synapse
Heightened sensitivity to a neurotransmitter after the destruction of incoming axons.
Heightened sensitivity as a result of inactivity by an incoming axon
What destroys DA neurons
Recovery from brain damage early in life more extensive than after similar damage later in life
supervised practice of the impaired bahaviors. Help the brain-damaged person find their lost skills or learn to use remaining abilities more effectively.
Prevent the calcium form entering the cells
promate restoration of damaged neural tissue
Replacing dead brain cells with healthy ones from a donor. Mostly used in parkinson's
An opening in the center of the iris in which light enters the eye. It is focused by the lens
Rear surface of the eye, which is lined with visual receptors
Light that enters the eye strinkes which half
the opposite side it entered from
Neurons located close to the center of the eye. The retina, receptors sends their messages to these cells
bipolar cells send their messages here. The neurons located even closer to the center of the eye. Join together and loop around and travel back to the brain
the ganglion cells join together to form the
the point at which the optic nerve leaves the eye
central portion of the macula specialized from acute detailed vision. It has the least impeded vision as blood vessles and ganglion cells are almost absent.
the ganglion cells in humans and other primates. These cells are small and each receives an input from a single cone
midget ganglion cells
Neurons with fixed excitatory and inhibitory zones in their reciptive fields; these cells are found only in the primary visual cortex (V1). Have bar shaped or edge shaped receptive fields.
Located in either v1 or v2 these neurons have receptive fields that respond to particular orientations of light but cannot be mapped into fixed excitatory and inhibitory zones. Receive their input from a combination of simple cells.
resemble complex cells but also have a strong inhibitory area at one end of their bar shaped receptive field
end-stopped (hypercomplex) cells
cells in the visual cortex are grouped together in columns perpendicular to the surface according to their responsiveness to specific stimuli. Cells may respond only to visual input from the left or right eye.
columnar organization of the visual cortex
Neurons whose responses indicated the presence of a particular feature. The fact that prolonged exposure to a given visual feature decreases sensitivity to that feature supports this concept