Studying of the Brain The Developing Brain

› Neurogenesis The Brainstem

› The Hindbrain› The Midbrain

The Forebrain› Cerebral Cortex

Lobes of the Brain› The Limbic System

Structures

One early approach to mapping brain functions involved examining the bumps on a person’s skull.

Case studies of individuals with brain damage have provided valuable insights into behavior in such area as memory, speech, emotion, movement, and personality.

Lesions- surgically altering, removing, or destroying specific portions of the brain› In humans, lesions are produced for medical reasons,

such as when part of the brain is surgically altered or removed to relieve uncontrollable seizures

Electroencephalograph- allowed scientists to record the brain’s electrical activity through the use of large, disk-shaped electrodes placed harmlessly on a person’s scalp

By three weeks after conception, a sheet of primal neural cells has formed. This sheet curls to form the hollow neural tube.

The neural stem cells divide and multiply, creating specific cells that eventually produce neurons and glial cells.

As the neural tube expands, the cavities develop, called the ventricles.

During peak periods in the brain development, new neurons are being generated rapidly.

Triggered by chemical signals, the new neurons travel to specific locations.

For many years, it was thought that the mature brain could lose neurons, but not grow new ones.

But new studies showed that the hippocampus, a brain structure that plays a vital role in forming new memories, has the ability to generate new neurons throughout the lifespan.

Studies since this discovery have shown that stress, exercise, environmental complexity, and social status have been shown to affect the rate of neurogenesis in rats, birds, and monkeys.

But it is unknown if these findings can be applied to the human brain.

Includes the hindbrain and midbrain› Located at the base of the brain

Hindbrain:› A region at the base of the brain that

contains several structures that regulate basic life functions

Midbrain:› The middle and smallest brain region,

involved in processing auditory and visual sensory information

Connected to the spinal cord with the rest of the brain

Made up of three structures› Medulla: Lies directly above the spinal cord;

contains centers active in control of breathing, heart rate, and digestion; also controls swallowing, coughing, vomiting, and sneezing

› Pons: swelling of tissue; relay information from various other brain regions to the cerebellum

› Cerebellum: controls balance, muscle tone, and coordinated muscle movements; affected by alcohol consumption

Relay station that contains centers important to the processing of auditory and visual sensory information

Process auditory sensations from the left and right ears

Helps you visually locate objects and track their movements

Substantia nigra: in midbrain; contains a large concentration of dopamine-producing neurons

Cerebral Cortex: outer portion of forebrain› Only a quarter an inch thick› Mainly composed of glial cells and neuron cell

bodies and axons Gray matter (in reference to color) White matter consists of myelinated axons that

connect cerebral cortex to other brain regions› Divided into two cerebral hemispheres connected

by corpus callosum Cerebral hemispheres are then divided into four

lobes Temporal, occipital, parietal and frontal lobes

Temporal Lobe› Contains primary auditory cortex

Occipital Lobe› Contains primary visual cortex

Parietal Lobe› Involved in somatosensory information (somatosensory

cortex) Frontal lobe

› Largest lobe› Primary motor cortex› Involved in planning, initiating, and executing voluntary

movements Association Areas

› Located on all lobes › Combine sensory and motor information › Coordinate interaction among different brain areas

Limbic System: structures that form a border around brainstem and are involved in emotion, motivation, learning, and memory.› Plays a critical role in learning, memory, and

emotional control

Hypothalamus› Regulates behaviors related to survival

Eating, drinking, and sexual activity› Often referred to as “the brain within the brain”› Controls secretion of endocrine hormones

Influences anterior and posterior pituitary glands Amygdala

› Clump of neuron cell bodies at the base of temporal lobe

› Involved in emotion and memory