PSY209 exam 1

somatic intervention

manipulating the body may affect behavior

somatic intervention: administer a hormone

behaviors affected: strength of mating behavior

somatic intervention: stimulate brain region electrically

movement toward goal object

somatic intervention: cut connections between parts of nervous system

behaviors affected: recognition of stimulus

behavioral neuroscience summary

• through somatic behavior manipulations we are able to examine how the brain responds and changes through experience

• this change in brain functions reflects neuroplasticity

• can be relatively protracted as well as short acting

five major perspectives of behavioral neuroscience

• describing behavior (structurally and functionally)

• studying evolution of behavior

• observe development of behavior and its biological characteristics over the lifespan

• studying biological mechanisms of behavior

• studying applications of behavioral neuroscience

true or false: brain can feel pain

false; brain cannot feel pain; meninges can feel pain (line the skull) but the brain itself cannot

true or false: sleep deprivation can affect the brain in many ways

true; even though we don't know what sleep does, we know it is vital

true or false; you don't generate new neurons beyond adolescence

false; neurogenesis allows for cells to regenerate; can be great for retaining new info; essentially the idea of rewiring the brain

true or false: exercise is just as good for your brain as it is for your body

true; allows for the efficient transmission of nutrients and chemicals throughout the brain; keeps our brains computationally intact; neurogenesis is more readily promoted by exercise

true or false; majority of brain cells are neurons

false; majority of brain cells are glial cells

glial cells

a type of cell that provides physical and chemical support to neurons and maintain their environment

true or false: surgical removal of almost half your brain is possible with little to no effect on personality or memory

true; your brain is mostly fat

central nervous system (CNS)

brain and spinal cord; coordinates the activities of the whole body

peripheral nervous system

the sensory and motor neurons that connect the central nervous system to the rest of the body; all parts of the nervous system found outside the skull and spinal columns

the brain

• the largest component of the CNS

• the major unit responsible for the functions of the CNS

• encased in the skull and protected by the cranium

blood brain barrier (BBB)

protects the brain; makes movement of substances from the blood into the brain more difficult than other organs

brain is composed of more than -------- neurons, which convey information necessary for control of our body and ability to interact with our environment

80 billion

glia means...

"glue" in greek

glial cells...

• support neuron functions

• communicate with each other and with neurons

• alter neuron structure and excitability

four types of glial cells

1. Astrocyte

2. Oligodendrocyte

3. Microglia

4. Schwann cell

Nodes of Ranvier

bumps on a myelin sheath around the axon of a neuron; information jumps from those nodes, which helps them rapidly shoot down a neuron, allowing for quick communication

neurons are like snowflakes because...

none are exactly the same in length; it depends on your physiology

what is released from the axon terminal depends on...

the cell it is on and what information it is programmed to release

different views of the brain

• horizontal plane view

• sagittal plane view

• coronal plane view

directional terms used to identify specific brain regions of interest

• anterior

• posterior

• dorsal

• ventral

• medial

• lateral

CNS lobes

• frontal

• parietal

• occipital

• temporal

frontal lobe

personality, movements, memory

parietal lobe

touch, visual, auditory, and integration of information

occipital lobe

sensory info, mostly visual

temporal lobe

memory, brain machinery, auditory info

anterior

front

posterior

back

dorsal

top

ventral

bottom

medial

middle

lateral

sides

brain is dominated by how many cerebral hemispheres?

2

gyri and sulci

the ridges and furrows of tissue of the cerebral cortex

purpose of gyri and sulci

Increases the surface area of the brain for storing more info

corpus callosum

200 million axons that interconnect the two hemispheres

Phineas Gage

railroad worker who survived a severe brain injury that dramatically changed his personality and behavior; case played a role in the development of the understanding of the localization of brain function

executive human brain functions of prefrontal cortex

• balance short term rewards and long term goals

• impulse control

• modulation of intense emotions

• shifting behaviors when situations change

• weighing possible consequences of behavior

• simultaneously considering lots of info when faced with complex challenges

• inhibiting inappropriate behavior

• forming strategies and planning

• organizing thoughts/problem solving

• focusing attention

• considering future

prefrontal cortex overall use

value based decision making

cerebral cortex has 6 distinct layers that are distinguished by

• type of neuron

• pattern of dendrites or axons

• pyramid-shaped cell body in layer III or V

von economo neurons (VENs)

special type of bipolar neurons in the cortex; humans have way more VENs than all other species

basal ganglia

important in motor control

basal ganglia include four nuclei:

1. caudate nucleus

2. putamen

3. globus pallidus

4. substantia nigra (midbrain)

parkinson's disease

neurogenerative disorder caused by degeneration of neurons in the substantia nigra area of the basal ganglia- unable to produce dopamine

limbic system

• complex system of nerves in the brain

• near the edge of the cortex

• has to do with instinct and mood

thalamus

complex clusters of nuclei that act as a relay box directing sensory info to appropriate higher-order regions like the cortex

thalamus is like a physician because...

it diagnoses information from different sensory modalities (gustation, tactile, auditory, visual)

once the thalamus receives information...

it transmits it to different areas of the brain for subsequent processing

Hypothalamus

hub for many vital regulatory functions including hunger, thirst, temperature, and sex

hypothalamus is vastly connected with numerous other brain systems important for...

cognition, mood, motoric behavior

midbrain

comparatively smaller than the forebrain and hindbrain

ventral tegmental area

responsible for motivting us toward goals (good or bad goals)

hindbrain

more simple than cortes, controls lower order functions; important for motor control and coordination as well as certain forms of basic learning

pons

attached to the cerebellum; contains motor and sensory nuclei and gives rise to cranial nerves

pons is important for...

• relaying signals from the forebrain to the cerebellum

• regulatory functions including sleep, respiration, and facial sensation

medulla

A brain stem structure involved in many essential body functions, such as heartbeat, breathing, blood pressure, digestion, swallowing

medulla contains...

cranial nerve nuclei, making it important for information processing between brain and body

techniques developed to visualize different forms of neurons as well as to help identify neurons that express certain proteins and/or neurotransmitters

• DAPI stain

• Nissl stain

• Immunocytochemistry

• In situ hybridization

• Ca^2+ imaging

DAPI stain

a fluorescent stain that binds strongly to DNA in a cell

Nissl stain

fills out the cell bodies of the neuron and works by the dye binding to any RNA in the cell; this can be used to measure size and density of cell

In situ hybridization

method in which a probe labels a specific DNA or RNA sequence in the cell; this technique results in clear expression of cell type

immunocytochemistry

uses antibodies to label the proteins from a cell

calcium imaging

when cells fire they release Ca^2+, which can be imaged using a miniscope in awake behaving animals

multiple neurons

one axon, many dendrites; most common type

bipolar neurons

one axon, one dendrite

unipolar neurons

a single extension branches in two directions forming a receptive pole and an output zone

how is information processed by the brain

debated whether the brain functions as a global system or a collection or relatively independent elements

Camille Golgi

• italian scientist, developed a procedure where silver chromate revealed the structure of individual neurons

• developed the reticular theory

reticular theory

suggests everything in the nervous system reflects a single continuous network (network known as "reticulum")

Santiago Cajal

used the golgi technique to reveal a few individual cells standing out, and importantly, that there were gaps between cells

Neuron Doctrine

The hypothesis that the brain is composed of discrete nerve cells that are essential units for information processing (Cajal's theory)

synapses

gaps between cells where information is transmitted from cell to cell; electrical and chemical information passed through synapses

each neuron has how many synapses?

between 5000 and 10000 synapses; this means the brain can have over 100 trillion synapses

when describing the passage of info from one neuron to the next, neuron 1 is known as the (1)------- neuron and neuron 2 is known as the (2)-------- neuron

1. presynaptic

2. postsynaptic

synaptic cleft

The narrow gap that separates the presynaptic neuron from the postsynaptic cell.

synaptic vesicles

Tiny pouches or sacs in the axon terminals that contain specialized chemicals called neurotransmitters

synapses can be divided based on the type of information being processed. This information can be either

electrical alone (uncommon) or chemical and electrical

electrical synapses

• much smaller than chemical and electrical combined

• work by large ions alone freely passing from one neuron to the next

• electrical synapses are very quick

chemical synapses

include both electrical and chemical information

transmission in the CNS can occur in multiple ways:

• neuron to neuron

• the ventricles contain cerebrospinal fluid, which can assist with neuronal communication

• ependymal cells line the brain ventricles and interact with neurons to cause release of chemicals into cerebrospinal fluid

diffusion of ions through

ion channels

electrostatic pressure

distribution of electrical charges (opposites attract; like repel); mediates resting potential

membrane permeability

the membrane of a cell separates the interior from exterior and can be selectively permeable; open and close depending on status of the cell

leak potassium channels are open during

resting potential

sodium-potassium pump

mechanism that pushes sodium out of the cell and potassium into the cell

resting potential

reflects a period when a neuron is not being influenced by other neurons nor is it producing its own signals

how to know that a neuron is at rest

• by inserting a microelectrode into the neuron we can compare its interior charge relative to its exterior charge to determine its resting membrane potential

Oscilloscope

a laboratory instrument that is capable of displaying a graph of voltage as a function of time on the face of a cathode ray tube; used in determining resting potential

plasma membrane of neurons...

prevents ions from entering or leaving the cell

ions involved in the resting potential of a cell contribute to its ----- charge

negative

during resting potential most ion channels are...

closed

resting potential reflects a balance between...

diffusion and electrostatic pressure

Na+

Sodium

K+

Potassium

Nernst potential

the theoretical intracellular electrical potential that would be equal in magnitude but opposite in direction to the concentration force