Behavioral neuroscience ch 2

Dr. Kosits Psyc 316

Astrocytes

glia cell, looks like stars

• Bring nutrients to neurons and storing biochemicals (glucose and neurotransmitters)

• Also may provide assistance to damaged neuron brain sites

• Recent evidence suggests they can influence mood as well, and abnormalities can contribute to mood disorders

Oligodendrocytes

• Myelin sheath in CNS

• Speeds up information moving

Shwann cells

• myelinate in PNS

Microglia

tiny glial cells used for cleanup

Radial glial cells

used in early brain development to “scaffold” or guide neurons to their final place of action to help the pathways form

• glial progenitor cells: immature glial cells in learning

Somatic division

part of the peripheral nervous system (PNS)

1. sensory nerves that carry info to the CNS (afferent)

autonomic division

PNS division that monitors and controls state of internal organs

1. sympathetic: prepares body for emergency situations via:

• accelerating heart rate and arousal

• directing blood flow to muscles

• causing overall high arousal levels

2. parasympathetic: opposite, restores resting state and stores energy via

• slowing heart rate

• increasing digesting

NOTE THAT THEY ARE BOTH ON AT SAME TIME JUST AT DIFFERENT LEVELS

Central nervous system

• Brain and spinal chord

• Somatosensory (bodily sensation) feeling occurs here

• Efferent nerves: carry motor info from CNS to periphery

 

 

3 membranes surround and protect spinal cord and brain:

1. Pia matter

2. Arachnoid matter

3. Dura matter

Carries info both in and out of brain

ventricles

center of spinal cord “butterfly”

• fluid filled chambers containing cerebral spinal fluid

• helps keep brain buoyant, acts as cushion from mech damage, assists in maintaining chemical stability, and carries nutrients to brain

• Four types:

  • 2 lateral ventricles (left and right), third ventricle, and fourth ventricle

• Cerebral aqueduct: chamber that connects third and fourth ventricles

• Choroid plexus: where cerebrospinal fluid

medulla

brainstem, located above spinal cord

• Governs essential physiological processes such as respiration, sleep, and regulation of blood pressure and cranial nerves controlling head and neck movement and sensation

• Axons that carry motor commands pass through medulla en route to spinal cord

• Axons carrying sensory info from periphery go through medulla to forebrain

Pons

• Appears as a swelling in brainstem

• Huge number of axon bundles that provide intimate connection between pons and cerebellum

• Has neurons that are important in sleep and waking states

• Helps with respiration and heart rate

Cerebellum

• Lies behind pons

• More neurons than are in rest of brain!

• Helps with carrying out movements (not carrying out tho)

• Key for motor learning

Midbrain

• Lies above pons

• Has 2 neuron lusters that release dopamine to wide areas of forebrain

  • Substantia nigra: one cluster that plays a role in movement

  • Ventral tegmental area: cluster for reinforcement and addiction

• Inferior and superior colliculi: two pairs of small bumps important for orienting and attending to auditory (inferior) and visual (superior) events

Diencephalon

lies just above brainstem

thalamus

Diencephalon, transmits sensory info to cortex

• Size of walnut shell

• Acts as a relay for sensory info (besides smell!) on route to cerebral cortex

• Damage isolates cortex from much of outside communication

• Made up of about 30 bilaterally symmetrical clusters of neurons on both left and right sides of the midline of brain

  • Each nuclei transmits a distinct kind of info, then send directly to appropriate sensory areas of cortex

• Also involved in motor planning by transferring info for body movements to brain areas

Hypothalamus

diencephalon, motivation

• Also has dozens of small nuclei

• Size of almond

• Key role in motivated behaviors such as sex, eating, thirst, sleep, and body temp. maintenance

• Strongly influences pituitary gland, which rests just below it

Pineal gland

diencephalon, sleep regulation

• Pea sized

• Releases hormones into bloodstream

• Considered master gland, cuz hormones from this gland influence other glands, including ovaries and testes

• Releases melatonin for sleep