NSPY199a Exam 1

Motor "homunculi", when stimulated makes participant want to move

Located immediately posterior to the central sulcus, contains the primary somasensory "homunculi" of the cerebral cortex. When stimulated participant feels like they are being touched

developmental process that occurs throughout a lifespan

process of elimination of dendrites

the cell bodies of neurons

neurotransmitter is released from the pre-synaptic neuron and opens the gates of the post-synaptic neuron for ions to flow through

coronal

sagital

Parietal Cortex (sends goals) --> Prefrontal Cortex (Plans) --> Premotor Cortex(Sequences) --> Motor Cortex (Executes)

responds to sensory signals that lead to a movement, plans complex behavior

Prepares for, coordinates movement, complex motor sequences

Prepares for rapid series of movement

coordinated movements, does not control individual muscles directly, but rather individual movements

some responds to current or future movements, some to "stimulusesponse mixtures"

Spontaneous movement, projects to spinal cord & primary motor area, some are somatotopy

all muscles of body can be mapped to area on primary motor cortex

referring to body sensation, particularly touch and pain sensation

Ventral anterior nucleus, Ventral lateral nucleus, ventral posterolateral nucleus

Frontal lobe neurons that fire when performing certain actions or when observing another doing so. The brain's mirroring of another's action may enable imitation, language learning, and empathy.

primary motor cortex, supplementary motor cortex, premotor cortex, primary somatosensory cortex, ipsilateral cerebellum

primary motor cortex, supplementary motor cortex, premotor cortex, ipsilateral cerebellum

organize action movements, dopamine, initiates or inhibits movement, control muscle force

Caudate Nucleus, Putamen, Globus Pallidus

- globus pallidus internal acts like a volume control on the motor cortex;
- If it is turned up, movement is blocked;
- If it is turned down, movement is allowed

When this pathway is activated, the globus pallidus internal is activated and inhibits the thalamus, thus blocking movement.

When this pathway is activated, the globus pallidus internal is inhibited, and the pathway is freed to produce movement.

loss of timing in movement and perception, problems with movement accuracy, balance, eye movements, upright posture, and walking, does NOT disrupt reaching, grasping, or finger movement

the cerebellum adjusts movement accuracy based on visual input

dorsal root conveys sensory info to spinal chord, ventral root conveys motor commands to muscles

nerve fibers decending from the left hemisphere motor cortex to the spinal chord

crosses the midline to control the movement of limbs and digits on the oposite side of the body

moves muscles in the body's midline

F, sometimes the muscles and spinal chord are enough

a distorted representation of the human body, based on a neurological "map" of the areas and proportions of the human brain dedicated to processing motor functions, or sensory functions, for different parts of the body.

Conect motor cortex with midbrain, recieve input from neocortex (motor, limbic, etc.) and nigrostriatal dopamine pathway from substantia nigra, output to motor cortext and substantia nigra

muscular, conductive (myelination), basal ganglia, cortical

Muscular Dystrophy, causes progressive weakness and loss of muscle mass, observed early in life, shortens life span

Multiple Sclerosis, Autoimmune disease charaterized by demyelination of neurons, causes slow deterioration of axons producing lesions in the brain (sclera), not fatal, cause unknown

numbness or weakness in one side of the body at a time, tremor, lack of coordination, bladderowel problems, vision problems, slurred speech, fatigue, dizziness, cognitive impairments, tingling, acute attacks

pharmaceutical injections of corticosteriods treats symptoms

Hypokinetic- rigid syndrome(loss of movement), Hyperkinetic-dystonic syndrome (increased motor activity)

Hypokinetic Disorder caused by degeneration of the dopaminergic neurons in the substantia nigra, results in 90% dopamine loss, symptoms vary, men 50% more likely to develop, not fatal

significant site of dopamine production in the brain. Direct projections to the striatum of the basal ganglia

Split into positive and negative, Positive: tremor at rest, slowness of movement, muscular rigitity, involuntary movements, akathesia (urge to moveepeditive movements), Negative: Postural disorders, righting disorders (difficulty standing up), locomotive disorders (initiating movement), Speech disturbances (lack of tone), Akinesia (poverty of movement)

Loss of excitatory inputs from substatnia nigra results in overinhibited thalamus which underexcites the cortex, creating problems initiating movement.

Indirect pathway: Loss of inhibitory inputs from substantia nigra results in overinhibited thalamus which underexcites the cortex, creating bradykinesia & dyskinesias.

no cure, physical therapy, psychological counseling, targeted ablation of involved structures, pharmacological therapy

L-Dopa, Amantadine, Mirapex, MAO B inhibitors, try to mimic dopamine, prevent dopamine breakdown, create dopamine, or aliviate symptoms

Deep brain stimulation, stem cell transplants (increasing number of dopamine producing cells)

1.5 Tesla

behavior of hydrogen atoms in response to changees in magnetic fields

measures relaxation time required for the hydrogen atom to "relax"

change from random orientation to orient parallel or antiparallel and their spins synchronize

the different relaxation times hydrogen atoms have in CSF, gray matter, and white matter

an edogenous signal of an fMRI, stands for Blood Oxygenation Level Dependent, Oxyhemoglobin repels magnetic field, deoxyhemoglobin attracts it--> different reaction times known as hemodynamic response

once one egg

once two eggs

measures flow of ions generated by pooled post-snaptic potentials, (large populations of neurons (pyramidal)) (synchronous activity) (neurons perpendicular to surface)

EEG: continous record of voltage, seeks to identify relative power of dif frequencies, ERP: record of voltage changes directly after an event, seeks to identify regular changes in voltage that follow the event

latency (time of peak amplitude post stimulus), amplitude (height of peak), distribution (lateral asymmetry- bigger in one hemisphere than the other, anterior/posterior asymmetry)

a pair of equal and oppositely charged or magnetized poles separated by a distance

measures magnetic field generated by local field portentials of pyramidal cells, allows measurement of more interior pyramidal cells since it measures fields perpendicular to the cerebrum

SQUID sensors

tracks the emission of positrons from a radioactive isotope that binds to glucose in blood supply

The ____ or antielectron is the particle with an electric charge of +1 e, a spin of 1/2 (the same as the electron), and the same mass as an electron. It is the antiparticle ( antimatter counterpart) of the electron.

Given brain damage to a specific region, observe pattern of behavioral deficits and infer function, can't control extent & location of damage, can't control characteristics of patients, can't reveal entire network involved in a process

electrical current induces a magnetic field, perpendicular to the electrical current, which induces an electrical current in the brain, frequency of the current determines whether effect is excitatory or inhibitory

50% of optic fibers, 90% of motor and somatosensory fibers

directly stimulate brain area of interest, ask patient to produce behavior of interest

comprised of sympathetic and parasympathetic systems

part of the autonomic nervous system, controls "fight or flight" response, spinal nerves in the thoracic and lumbar regions are connected to the sympathetic ganglia

part of the autonomic nervous system, controls "rest and digest" response, connects with parasympathetic ganglia near target organs, connects with spinal chord, greatly made up of facial, vagus, and oculomotor cranial nerves

Spinal nerves (Cervical nerves, thoracic nerves, lumbar nerves, sacral and coccygeal nerves), and cranial nerves

facing back, afferent fibers enter the spinal cord, carries sensory info to the brain

facing forward, strand of efferent fibers leaving the spinal cord, carries motor information to the body from the brain

upper hindbrain, connects the cerebellum with the rest of the brain

regulates vital functions such as breathing and the functioning of the cardiovascular system

recieves sensory input, colliculi mediate orientation to sensory input in space

made up of the thalamus and hypothalamus

22 small nuclei, interacts with the pituitary gland, takes part in nearly all aspects of motivated behavior: temp regulation, feeding, sex, sleeping, emotional behavior

20 nuclei, relays sensory information, relays info between cortical areas and forbrain and brainstem

motor

emotion

thalamus, hypothalamus, frontal lobe, olfactory bulb, amygdala, hippocampus

Neocortex (cerebral cortex), expanded a lot during evolution, 80% of the human brain

posterior connection by the central sulcus, inferiorly by the lateral fissure, and medially by the cingulate cortex

layers V.(Internal pyramidal cells) and III. (External pyramidal cells)

executive functions, thinking, planning, organizing, and problem solving, emotions and behavioral control, personality

movement

sensations

perception, making sense of the world, arithmetic, spelling

memory, language, understanding

vision

cell birth (neurogenesis; gliogenesis), cell migration, cell differentiation, cell maturation (dendrite and axon growth), synaptogenesis (formation of synapses), cell death and synaptic pruning, myelogenesis (formation of myelin)

happens during neuronal maturation, includes: dendritic arborization, growth of dendritic spines, is a slow process, continues after birth

part of neuronal maturation, they have specific targets to reach, some grow away from the cell body, some travel far, some follow chemical/electrical signals

develops fairly homogeneously across brain regions

develops heterogeneously across brain regions; this is unique to humans.
Occipital – fastest rate
Frontal – slowest rate

process begins at ages 6/7yrs in dorsal parietal and sensorimotor regions

all other 'filler' cells in the cortex, created throughout lifespan, support various neural functions

Begins when neuronal proliferation/neurogenesis and migration are nearly complete
Continues until early adolescence but is possible throughout the lifespan
Rate is heterogeneous across brain regions

all-or-none nerve signals created by temporal summation of graded potentials, sent along an axon

influx of positively charged sodium ions into the intracellular fluid, decreasing the negativity of the charge inside relative to the outside of the cell.

1) Action potential
2) Ca2+ influx through voltage-gated channels
3) Exocytosis (1-2 ms)
4) Ion influx through ligand-gated channels (AKA receptors)
5) Clean up (breakdown or re-uptake)!

19-25 days post fertalization folding of the neural plate creates the neural tube

from the 6th & 7th embryonic week to 18th week, all the cortical neurons are created with the neural tube

towards the surface

chemical gradients, radial glial cells

Membrane slightly depolarized
Na channels open
K+ channels open
Re-equilibration
“refractory period”

effect: you increase activation of post-synaptic neurons