1. Neuroscience and Behavior
Schacter
Gilbert
Wegner
PSYCHOLOGY
Chapter 3
Neuroscience and Behavior
Slides prepared by
Randall E. Osborne, Texas State University-San Marcos

2. The Neuron
Highly specialized cell that communicated information in electrical and chemical form
A nerve cell

3. The Cell Body
Processes nutrients and provides energy for the cell to carry out its functions; contains the nucleus of the cell
Graphic from Hockenbury slides
Key words: Cell body; soma; cell nucleus
Interesting facts:
The DNA in the nucleus of the cell has lost its ability to divide. therefore, when a neuron dies,for the most part, the adult brain cannot simply grow new neurons. (Note there are a few exceptions to this rule.)
The relative inability to grow new neurons leads to two interesting questions:
Q1: How do brain tumors (cancer) occur?
A: Unlike neurons, glial cells can divide and grow new cells throughout one's lifetime. Most brain tumors are limited to glial cells, not neurons.
Q2: If a person cannot grow new neurons, how does the brain change in order to accommodate new learning?
A: One mechanism by which the brain adapts to help you learn new information involves the structure on the next slide: the dendrites.

4. Dendrites
Multiple short fibers that extend from the cell body and receive information from other neurons or from sensory receptor cells

5. Axon
The long, fluid-filled tube that carries a neuron’s message to other body areas
2 distinct parts
tube-like structure
branches at end that connect to
dendrites of other cells
Hockenbury slides (Schulman)
Key words: axon; action potentials
Interesting facts:
- The diameter of an axon may vary from approximately 1mm-20mm.
- An axon may travel long distances to reach it's destination (longest axon is approximately 3 feet in humans and 10 feet in giraffes).

6. Myelin Sheath
A white fatty covering wrapped around the axons of some neurons that increases their communication speed
Multiple sclerosis involves the break down of myelin in patches which causes the neural message to be slowed or interrupted
Graphic from Hockenbury slides
Key words: myelin sheath; action potentials; axon
Interesting facts:
- The myelin sheath is NOT a part of the axon. The myelin sheath is actually formed of glial cells (oligodendricytes and Schwann cells) that wrap around the axon.
- You may have often heard the brain referred to as either white matter or gray matter. The myelin sheath appears white in nature. Hence, the term white matter refers to areas of the brain that are myelinated. Gray matter refers to areas of the brain that are unmyelinated.
- When you accidentally cut yourself, you often visually notice that you've cut yourself before you actually feel any pain from the cut. The reason for this is that visual information uses myelinated axons; whereas, pain information uses unmyelinated axons.
- The loss of myelin is a significant factor in the disease multiple sclerosis (MS). When myelin is lost, the high-speed transmission of information is slowed down or blocked completely, which could lead the person with the inability to walk, write or speak.

7. Neural Communication Two basic types Communication within the neuron
electrical
Communication between neurons
chemical

8. Communication Within the Neuron
Neurons communicate by means of an electrical signal called the Action Potential
Action Potential- a brief electrical impulse by which information is transmitted along the axon of a neuron

9. Communication Within the Neuron
Resting potential- state in which the neuron is prepared to activate and communicate its message if it receives sufficient stimulation

10. Resting Potential
Graphic, Hockenbury slides

11. Depolarization Ahead of AP
Graphic from Hockenbury slides

12. Repolarization follows
Graphic from Hockenbury slides

13. Communication Between Neurons
Synapse- the point of communication between two neurons

14. Communication Between Neurons
Neurotransmitters- chemical messengers manufactured by a neuron

15. Types of Neurotransmitters
Acetylcholine
Dopamine
Serotonin
Norepinephrine
GABA
Endorphins

16. Neurotransmitters

17. Acetylcholine (Ach)
Neurotransmitter that causes muscle contraction and is involved in memory function
Alzheimer’s disease is associated with severe depletions of Ach
Graphic, Hockenbury slides

18. Dopamine
Neurotransmitter involved in the regulation of body movement, thought processes, and rewarding sensations
Loss of dopamine-producing neurons is cause of Parkinson’s disease
Schizophrenia is characterized by an excess of dopamine

19. Parkinson’s Disease
Loss of dopamine-producing neurons in the Substantia Nigra (an area of the midbrain) is cause of Parkinson’s disease

20. Serotonin Neurotransmitter involved in sleep and emotions
Low levels of serotonin have been associated with depression

21. Norepinephrine
Neurotransmitter involved in learning and memory; a hormone manufactured by adrenal glands
Helps body gear up in face of danger

22. GABA (gamma-aminobutyric acid)
Neurotransmitter that usually communicates an inhibitory message
Alcohol and Anti-anxiety medications increase GABA activity in the brain

23. Endorphins
Neurotransmitters that regulate pain perceptions; endogenous morphines
Opiates attach to these receptor sites
Acupuncture
Runner’s high

24. Nervous System Central (brain & spinal cord) Peripheral somatic
autonomic
sympathetic
parasympathetic

25. Nervous System Somatic Autonomic gather info. from external world
complementary systems

26. Brain Images Brainstem Hindbrain Midbrain Forebrain Limbic system
Cortex
Discovering PSY p Figure 2.16

27. Hindbrain
Hindbrain
medulla
reticular formation
cerebellum
pons

28. Medulla Breathing Heart rate Digestion Other vital reflexes swallowing
coughing
vomiting
sneezing

29. Reticular Formation Network of neurons in the brainstem (and thalamus)
Sleep and arousal
Attention
Myers, Exploring psy 4e Figure 2.10

30. Cerebellum Coordinated, rapid voluntary movements
e.g., playing the piano, kicking, throwing, etc.
Lesions to cerebellum
jerky, exaggerated movements
difficulty walking
loss of balance
shaking hands
Hockenbury slides

31. Pons
Helps coordinate movements on left
and right sides of
the body

32. Midbrain
Midbrain
Tectum
Tegmentum
Substantia Nigra

33. Substantia Nigra
An area of the midbrain that is involved in motor control and contains a large concentration of dopamine-producing neurons
These dopamine-producing neurons break down in those with Parkinson’s

34. Forebrain and Limbic System
cerebral cortex
Limbic System
thalamus
hypothalamus
pituitary gland

35. Limbic System
Limbic system
hypothalamus
Hippocampus
amygdala

36. Hypothalamus regulates behaviors related to survival sexual behavior
hunger, thirst
sleep
water and salt balance
body temperature regulation
circadian rhythms
Important role in hormone secretion
The hypothalamus is made up different subregions or nuclei. These nuclei generally differ in terms of gross anatomy and function.
Sexual behavior: The medial preoptic and medial anterior hypothalamic nuclei of the hypothalamus are heavily involved in mating behaviors of animals. Damage to these areas results in a loss of mating behaviors. Electrical stimulation of these areas (or insertion of sex hormones in these areas) can elicit sexual behaviors.
Hunger: Lesions to the hypothalamus can lead to severe obesity or extreme weight loss, depending upon the region damaged.
Thirst: Electrical stimulation of the hypothalamus can cause an animal to start drinking even in animals that have plenty of water in their systems. Neurons in the supraoptic nucleus of the hypothalamus are sensitive to changes in the osmolarity of blood. These neurons control the secretion of vasopression, which is more commonly known as "anti-diuretic hormone" or ADH. ADH acts in the kidney to increase fluid retention.
Sleep:
Temperature regulation: Your body tries to keep the same body temperature regardless of how hot or cold it is outside. The hypothalamus helps maintain a constant body temperature. Hypothalamus contains temperature-sensitive neurons. Neurons in the posterior hypothalamus become active when you are cold; whereas, heat activates the anterior hypothalamus. Changes in body temperature can cause the hypothalamus to imitate such behaviors as shivering, hunger, adrenaline secretion and fever to help you get back to the proper body temperature.
Circadian rhythms: the suprachiasmatic nucleus (or SCN) of the hypothalamus is thought to be involved in regulating the body's natural 24 hour rhythms.

37. Hippocampus
A curved forebrain structure that is part of the limbic system and is involved in learning and forming new memories

38. Amygdala
Forebrain structure and part of the limbic system that is involved in emotion and memories

39. Cerebral Cortex Cerebral cortex frontal lobe temporal lobe
occipital lobe
parietal lobe
corpus callosum

40. Lobes of the Cortex
Each cerebral hemisphere can roughly be divided into four regions or lobes
Temporal
Occipital
Parietal
Frontal

41. Temporal lobe
An area on each cerebral hemisphere near the temples that is the primary receiving area for auditory information

42. Occipital lobe
An area at the back of each cerebral hemisphere that is the primary receiving area for visual information

43. Parietal lobe
An area on each hemisphere of the cerebral cortex that processes somatic information

44. Frontal lobe
The largest lobe of each cerebral hemisphere; processes voluntary muscle movements and is involved in thinking, planning, and emotional control

45. Somatosensory and Motor Cortices