Central Nervous System (CNS): Basic Facts Adult human brain is 2% body weight 20% resting oxygen 15-20% blood flow Consists of neurons and glial cells Neurons are the information processors Glia provide metabolic and structural support to the neurons Energetic needs Myelin Repair spinal fluid production and other functions

Size of Adult Human Brain Range: 1000 to 2000 grams Average male = 1,350 g Average female = 1,200 g Anatole France = 1,000 g (20th century poet) Albert Einstein = 1,230 g Lord Byron = 2,380 g (Romance poet)

Neurons 200 cell types 10 trillion cells in head 25 billion pyramidal neurons, connects to 1000s of other neurons

Gray & White Matter 60% white matter (axons) 40% gray matter (cells) 2 mph to 250 mph when myelinated

Neural Structure

Human neocortex has 6 layers, 4.5 mm at deepest point A pinpoint on the 2,200 square cm surface area in adults

52 Brodmann Areas (1906) based on different cell types and distributions

Forebrain = Cortex & Limbic Bottom to Top Back to Front Right and Left Forebrain = Cortex & Limbic

General Functions of lobes Occipital Vision Temporal Auditory Memory Parietal Touch Integration Frontal Motor Executive Function (goal-oriented, planning, sequencing)

Central Nervous System Fissures (large cleft) Lateral or Sylvan fissure Longitudinal fissure Central fissure or sulcus Sulcus (shallow cleft) Gyrus (tissue ridge)

Types of Neuroimaging: Positron Emission Tomography (PET)

(gray matter thickness map) MRI examples Anatomical MRI (T2-weighted) Anatomical MRI (T1-weighted) Functional MRI (activation to music) Structural MRI (gray matter thickness map) Diffusion Tensor MRI (white matter tracts) MRI is very versatile. Besides conventional anatomical images like the one where you can see different anatomical structures in the brain like tounge, brain, ventricles, there are other kinds of MRI. This one, for example, called an angiogram, shows spatial distribution of the blood vessesls in the brain. This image is an example of functional MRI. The color spots here show activated areas of the brain. This image is a 3D reconstruction of the brain. The different shades of blue show spatial variations in thickness of the cortical gray matter. We call this structural MRI. Finally, this image shows a map of some of the neural connection in the brain. We can get maps like this using so called DTI. Today, however, we are going to focus on two types of MRI: functional and structural imaging.

Electroencephalography (EEG) – Brainwaves