Brain and Behavior Test 1

What are the main methods used for understanding brain function?

Damage, Stimulation, Recording behavior w/ activity, Correlating Structures to Behavior

Lesion

Damage to a brain region

Ablation

Removal of a brain region

Stereotaxic Instrument

A device used to hold a subject (rat) in a standardized place to experiment on the brain

Transcranial Magnetic Stimulation

Use of magnetic pulses to stimulate or deactivate parts of the brain

Ways to stimulate the Brain

Electrodes and Transcranial magnetic stimulation

Electroencephalograph (EEG)

A cap of electrodes placed on the skull to record electrical impulses generated by the brain. Often used in sleep studies. 

Magnetoencephalograph (MEG)

A large device where a patient sits in a chair and a large machine is put over their head. Often used simultaneously with an EEG for seizures. Detects “interictal epileptic discharges” to determine source of seizures. 

Positron Emission Tomography (PET)

A patient consumes radioactive glucose, showing areas which require the most energy in the body. Often used to highlight cancers. Often used in combo with a CT/CAT scan (The one with contrast in the tube)

Magnetic Resonance Imaging (MRI)

Magnetic field imaging of brain. Either DTI or Structural.

DTI MRI

shows white matter+tumors w/ movement (diffusion) of water

Structural MRI

shows grey+white matter w/ shape size volume of structures. Combined is best

fMRI

Modified MRI, either BOLD or DTI. Used to map out brain for surgery to prevent damage to other regions of brain

BOLD fMRI

Blood Oxygen Level Dependent, tracks changes in blood oxygen in regions of brain

DTI fMRI

Maps white matter (axons) – outline white matter tracts to known structural brain lesions that are potentially resectable; Axons connect brain regions, which brain function is dependent on

Phineas Gage

Suffered lesion, bar through frontal lobe. Lead to personality change and impulse control loss

Henry Molaison (HM)

underwent ablation of both temporal lobes, no new memories (prograde amnesia), got rid of his hippocampus

Superior/Dorsal

Top of brain

Ventral

Bottom of brain

Lateral

Outer of hemispheres

Medial

Middle, inner of hemispheres

Sagittal

Upright, Front-to-back (longway)

Coronal

Upright, Left to right (Shortway)

Horizontal

Sideways, side-by-side

CNS

Brain and spinal cord

PNS

Any nerves not brain or spinal cord

Spinal cord roots

Sensory dorsal root ganglion, motor ventral root ganglion

Grey Matter

Dendrites and cell bodies

White matter

myelinated axons

Somatic

Voluntary

Autonomic

Involuntary

Sympathetic

Uses norepinephrine, fight or flight

Parasympathetic

rest and digest

Major/Gross structures

Forebrain, Midbrain, Hindbrain

Brainstem is comprised of…

Pons, Medulla, and all of the midbrain

Brainstem function

Relay messaged to/from spinal cord and regulate essential living functions

Cranial nerve functions

Allows brainstem to control head sensation and movement, also parasympathetic output to organs

Hindbrain structures

Pons, Medulla, Reticular formation, Raphe system, Cerebellum

Midbrain structures

Tectum, Tegmentum

Forebrain Structures

Thalamus, Hypothalamus, Pituitary Gland, Hippocampus, Basal Ganglia, Amygdala, Nucleus Accumbens, Cingulate Gyrus

Pons function

Uses ACH and Serotonin, increases readiness and arousal of other parts of brain

Pons Substructures

Medulla, Reticular formation, Raphe system

Medulla

Controls vital reflexes

Reticular formation

Extends to much of the brain, descending portion controls motor areas of spinal cord, ascending sends input to cerebral cortex to increase arousal and attention and regulate sleep/circadian rhythm/learning

Extends to much of the brain, modifying readiness to stimuli using serotonin

Cerebellum

Balance and movement

Tectum

Composed of superior and inferior colliculi which process video and auditory information respectively

Tegmentum

Composed of Substantia Nigra and Ventral Tegmental Area, starts and stimulates dopamine pathways

Thalamus

Takes in sensory input then sends it to appropriate area

Hypothalamus

Regulates Pituitary’s hormone production and is associated with motivated behaviors

Pituitary gland

Produces hormones, anterior is glandular and synthesizes hormones, posterior is neural extension of hypothalamus

Hippocampus

Critical for memory, especially long term and spacial/context

Basal Ganglia

Made of Caudate Nucleus, Putamen, Globus Pallidus

Planning movement, procedural habit memory, movement disorders

Amygdala

Fear and aggression

Nucleus Accumbens

Reward and aversion learning, Salience

Cingulate Gyrus

Processes emotions and regulates behavior