Behavioral Neuro

Behavioral neuroscience

Studying the neural bases of behavior and mental processes.

Neuroscience

the study of the nervous system

5 major research perspectives

• describing behavior

• evolution of behavior

• development of behavior and its biological characteristics over a life span.

• mechanisms of behavior

• applications of behavioral neuroscience

Neuroplasticity

ability of the brain to be changed by environment and experience (can occur in childhood → adulthood)

ex. little girl getting half of her brain removed and being able to eventually walk and run.

Somatic intervention:

Intervening on a bodily structure or function (hormone or memory)

Behavioral intervention

Intervening on a behavior

Correlation

Extent to which 2 measures relate to each other, not causation

How can social experiences alter the brain?

In rats social isolation leads to changes in the brain

What region is responsible for processing odors and is affected by play?

Postero dorsal medial amygdala

Even expectations can alter the brain, what region is implicated in processing emotion, (also pain), is more active when people believe that they are putting their hand in very HOT water vs. moderately hot.

The Dorsal Anterior Cingulate Cortex

board that weighs ethical consideration in animal research

IACUC-Institutional Animal Care and Use Committee

Non-human animal methods- advancements in —— have enabled selective staining of parts of neurons and glia

ex. see through mouse brain

Histology

Histology helps us know..

a) how neurons are structured

b)how neurons connect throughout the brain

c) which neurons are modulated by various events, among other things.

Hippocampus

where memories are formed

Optogenetics

Uses genetic tools to inset light-sensitive “opsins”, making light-sensitive ion channels into neurons.

channelrhodopsin

responds to blue light by allowing Na+ ions to enter, depolarizing the cell.

Halorhodopsin

responds to yellow light by allowing Cl- ions to enter, hyper-polarizing the cell.

Human methods- brain imaging has ——- and ——- limitations such as speed and accuracy trade offs

procedural and experimental

some techniques have —— spatial resolution (provide a lot of structural detail) but are relatively —- in making images.

high, slow

PET

Produces images of brain activity via radioactive tracer. Has moderate spatial precision and very low temporal precision

MRI

Produces high-resolution images using radio frequency energy. Has high spatial precision but low temporal precision.

DTI

uses MRI to study white matter tracts

fMRI

measures blood-oxygen level dependent signal (BOID) reflects IMPUT not output, axons.

MEG

measures the tiny magnetic fields given off by active neurons.

EEG

measures the tiny electrical fields given off by active neurons; commonly used to derive event-related potentials (ERP’s)

Event-Related Potentials (ERP’s)

index the brains response to a stimulus or condition. They have high temporal precision and can be derived from MEG or EEEG. They have low spatial precision.

Optical imaging

Uses near infrared light passed through the skull to reveal activity. It has high temporal precision and moderate spatial precision, but it is restricted to cortex.

Single neuron recording

Can be done in epilepsy patients. High temporal precision and high spatial precision.

TMS

excites or inhibits small region with magnets

tDCS

excites or inhibits a larger area of cortex with an electric current.

lesions

Traditional studies of brain focused on ——, or regions of damage, and how they influenced brain function

Neurons (nerve cells)

the most important part of the neurons system

Neuron doctrine

-the brain is composed of independent cells

-the info is transmitted from cell to cell across SYNAPSES

Glial cells

Provide support for neurons

Input zone

dendrites receive info-dendritic arborization (branching) reflects neural complexity

Integration zone

cell body-specifically, a cone-shaped area called “axon hillock”, which gives rise to the axon-integrates info.

Conduction zone

axons carry info away from the cell body.

-axons divide into axon collaterals, allowing a neuron to innervate more than one non-synaptic cell.

output zone

axon terminals have neurotransmitters released into the postsynaptic clept.

Synaptic vesicles, neurotransmitters

— in axon terminals contain chemical —-, which are released in response to electrical activity in the axon

presynaptic neuron to post synaptic neuron

info. is transmitted across synapses from the — to —-.

Synaptic cleft

gap that separates the pre and post synaptic membranes.

Receptors

in the postsynaptic membrane are specialized proteins that react when a neurotransmitter molecule binds to them.

postsynaptic potentials

are brief changes in the resting potential of the postsynaptic cell.

An excitatory postsynaptic potentials (EPSP)

is a small depolarization in the postsynaptic cell, pushing it CLOSER to threshold.

An inhibitory postsynaptic potential (IPSP)

a small hyper-polarization in the postsynaptic cell, pushing it FARTHER from the threshold.

Motor neurons

stimulate muscles or glands

sensory neurons

respond to environmental stimuli, such as light odor or touch.

Interneurons

receive input from and send input to other neurons

Astrocytes

star shaped cells that affect neurons in many ways

ex. monitoring neuron activity and regulating capillaries to provide more blood to neurons that are firing more than usual

microglial cells

the brains local immune system; small cells that remove debris and waste from injured cells.

oligodendrocytes

form myelin sheath in brain and spinal cord

mylenation

glial cells wrap axons with a fatty sheath, myelin, to insulate and speed conduction. Gaps where axon is exposed are called nodes of ranvier.

- orientations of viewing the brain

3

Horizontal plane

divides the brain (upper and lower)

sagittal plane

divides brain (left and right)

coronal plane

divides (front-anterior and back-posterior)

Dorsal

Superior=“top” ex. shark fin

Ventral

inferior= “bottom

Anterior

Rostral=”front”

Posterior

Caudal=”back”

lateral

away from the middle

medial

toward the middle

Grey matter

contains more cell bodies and dentrites lack myelin

White matter

consist mostly of axons with white myelin sheaths. ex. fat in meat

The brain has - cerebral hemispheres

2

cerebral cortex

folded outermost portion of the cerebral hemispheres, compromised mostly of neuron cell bodies, dendrites and axons

folds (gyri and sulci)

increase amount that can fit into the skull; grouped by lobed

the cortex has - lobes

4

frontal lobe

movement and high-level cognition

pariental lobe

spatial cognition

occipital lobe

visual processing

temporal lobe

auditory processing, sense of smell, aspects of learning

tracts of axons

cortical regions communicate via..

short tract

to nearby cortical regions

longer tract

to other parts of cortex

corpus callosum

connections between hemispheres is via the..

subcortical regions

long, multi-synaptic chains is through..

Basal ganglia

important in rewards and motor control

limbic system

includes structures important for learning and memory, cognitive functions, emotional regulation, sense of smell

thalamus

cluster of nuclei that relay sensory info

hypothalamus

contains nuclei with many vital functions (hunger, thirst, temp., regulation, sex, ect .); also controls the pituitary.

Receptor subtypes

There are many —-, so any given transmitter may excerpt multiple types of effects diff. receptor subtypes many trigger diff. responses in target cell.s

Types of neurotransmitters-

amine, amino acid, peptide, gas

Amine

acetylcholine, dopamine, serotonin

monoamines →

imazoleamines - histamine

catecholamines- dopamine, epinephrine, norephrine

Indoleamines- seratonin, melatonin

Amino Acid

GABA, glutamate

Peptide

short chain amino acids (neuropeptides)

Gas

soluble gases:nitric oxide, carbon dioxide

glutamate and asperatate

The main excitatory neurotransmitters are — and —

Glutamate

— is the primary excitatory neurotransmitter in mamalian brains

asperatate

— is an excitatory amino acid, but it may not be a neurotransmitter per se.

Gamma-amino butyric acid (GABA) and Glycine

The main inhibitory neurotransmitters are — and —

GABA

— is the main inhibitory NT in the mammalian brain, targeted by anxiolytics, which reduce anxiety

Glycine

— is excitatory during development, but inhibitory in adulthood, it is the primary inhibitory NT. in the brainstem and spinal cord.

-Basal forebrain and tegmental nuclei

-cholinergic

-learning, memory, muscle movements and pathology of Alzheimers

- nicotine, Benadryl, and alzheimers medications as well as some hallucinogens.

Acetylcholine, ACH

Brain ACH originates in the

Cells producing or receptive to it are..

Important in..

targeted by..

-Raphne nuclei

-serotongergic

-sleep, aggression, impulsivity, sexual behavior, and anxiety

-sleep, aggression, impulsivity, sexual behavior, and anxiety

-antidepressants anxiolytics and psychedelics

Serotonin 5, HT

brain 5-HT mostly originates in..

Cells producing or receptive to it are…

modulate..

are targeted by..

-Mesostriatal pathway, mesolimbocortical pathway

-dopaminergic

-motor control, rewards, reinforcement, and learning

-antipsychotics, stimulants, and drug abuse

Dopamine DA

Brain DA mostly originates in the substantia nigra (—-) and the ventral tegmental area (—)

cells producing or receptive to it are..

important in…

targeted by..

-locus coeruleus

-noradrenergic

-mood, arousal, and sexual behavior

-antidepressants and ADHD medications

Norepinephrine, NE

-Brain NE originates in the..

-cells producing or receptive to it are…

-NE systems modulate processes including..

-Targeted by..

Ligand

a substance that binds to a receptor

Agonist

initiates normal effects of the transmitter on a receptor

Antagonist

binds to a receptor and does not activate it, prevents binding by other ligands