Discussion Quiz 1

Lesion Study

uses physical or pharmacological methods to ablate neurons

Why is lesion study important

investigates the necessity of a brain region for a specific behavior or phenotype

Stereotaxic Surgery

positioning an electrode or cannula in specific position of brain

stereotaxic atlas

a map of drawings with brain sections of a particular animal with measurements that provide coordinates for stereotaxic surgery

Bregma

Junction of sagittal and coronal sutures of skull (reference point for stereotaxic brain surgery)

irreversible brain lesions

radio frequency , excitotoxic lesion

Sham Lesion

doesnt receive lesion markers, placebo

Radio Frequency Lesion

Current passed through electrodes producing heat and destroying brain tissue, not selective

Excitotoxic Lesion

Over Stimulates neurons until death

Reversible Lesions

Muscimol, Optogenetics,Channelrhodopsin, Halorhodopsin

Muscimol

GABA receptor agonist

Inactivates targeted brain region for hrs

Once cleared out brain goes back to normal

• Low Spatial Resolution

• Low temporal resolution

Optogenetics

stimulates particular types of neurons in brain region

Turning neurons on or off with light

Channelrhodopsin

Ion channel activated by blue lights

lets positive ions into neuron increasing firing potential

Halorhodopsin

Ion pump activated by yellow light

Transports Chlorine from outside to inside, making them more negative

Neuronal Tracing

Determines the pathway of brain activity so we know the connection between neural circuits

Anterograde labeling

moving forward

Retrograde Labeling

moving backwards

Neural Recording

techniques used so researches can record neural activity from a single neuron or population or neurons

Single-unit recording

recording from a single neuron using microelectrode

able to see clear action potential ave

high spatial and temporal resolution

EEG

records neural activity from population level

Low Spatial and Temporal resolution

Non-Invasive methods

CT , MRI, DTI, fMRI

CT Scan

structural information, x-rays, low spatial resolution

MRI

structural information of body parts, uses huge magnet, higher spatial resolution than CT

DTI

Modified MRI scanner to reveal the bundles of myelinated axons in brains

fMRI

Measures: Blood Oxygen Level Dependent, shows how well a body part is functioning

The best spatial resolution but not good temporal resolution

Sodium Potassium Pump Purpose

a protein that maintains membrane resting potential

Glial Cells

Astrocytes, Oligodenrdrocytes,Microglia