Recording and Stimulating Neural Activity

Bregma

A reference point for stereotaxic brain surgery, the point or area of the skull where the sagittal and coronal sutures joining the parietal and frontal bones come together

Excitotoxic Lesion

Destroy cell bodies in a particular region using the injection of chemicals

Radiofrequency (RF) Lesion

Destroy the cell bodies, axons and terminals in the region of the electrode by heating them

Electroencephalograms (EEGs)

Electrical brain potential recorded by placing electrodes on the scalp, great temporal resolution, poor spatial resolution

Anterograde Labeling Method

Employs chemicals that are taken up by dendrites or cell bodies and then transported through the axons toward the terminal buttons

Retrograde Labeling Method

Employs chemicals that are taken up by terminal buttons and carried backward through the axons toward cell bodies

Immunocytochemical Methods

Express proteins in brain, visible with dye, produce antibodies

Positron Emission Topography (PET)

Gives localization of a radioactive tracer (injected via IV) in a living brain, measures where receptors and axon terminals are located

Magnetic Resonance Imaging (MRI)

Hydrogen atoms start aligned with the magnetic field and get "knocked over" 90 degrees, and the rotation rate correlates to the realigning with the magnetic field, different structures have different amounts of water and therefore different relaxation rates

Fos Protein

Identifies neurons that have been recently stimulated

Stereotaxic Axis

Images that correspond to frontal sections of the brain taken at various distances

2DG Autoradiography

Measures local glucose utilization, determines locations of receptors by exposing them to a radioactive ligand solution

Microdialysis

Measures neurotransmitters that are released, subject (usually animal) is awake and engaging in activity, uses a dilute solution to pick up molecules that diffuse from the extracellular fluid, contents are frozen and analyzed

2DG PET

Measures regional metabolic brain activity

Functional Magnetic Resonance Imaging (fMRI)

Measures regional metabolism in the brain usually by difference in blood oxygen level

Diffusion Tensor Imaging (DTI)

Measures white matter pathways, doesn't give information on activity, used to determine integrity of white matter

Lesion

Process of damaging parts of the brain

Histology

Produce antibodies to any peptide or protein

Stereotaxic Surgery

Type of surgery that is used to perform a lesion, uses a stereotaxic axis

Magnetoencephalography

Recordes magnetic fields induced by neural activity, determines location of a group of neurons firing synchronously

Optogenetic Methods

Stimulates (or inhibits) neurons in the brain using light to depolarize or hyperpolarize the cells, insert algae proteins to be activated when stimulated by light

Transcranial Magnetic Stimulation

Stimulates neurons in the cerebral cortex with an electromagnet placed on the head

Electrical Stimulation

Stimulates neurons near the lip of the electrode and axons passing through the regions

Chemical Stimulation (with excitatory amino acids)

Stimulates only neurons near the tip of the cannula, not axons passing through the regions

2DG (2-deoxyglucose)

Sugar unable to be metabolized, used for autoradiography and PET

CT Scan

Used for head injury or stroke, identifies location of bleeding, can't see gyri and sulci

Macroelectrodes

Used to record electrical activity of a large number of neurons in a particular brain region, attached to scalp

Microelectrodes

Very small electrode, used to record electrical activity of individual neurons, can be permanently implanted, allows movement