Biopsychology

Biopsychology

the study of how biological processes influence behavior

Action potential

all or nothing change of voltage in a membrane (nondecremental)

Threshold of Excitation

voltage-gated Na+ channels are open

Depolarization

Membrane becomes positive

Peak Action Potential

Na+ gates snap shut, K+ gates open

Repolarization

membrane restores to negative, polarized value

Hyperpolarization

short period of time when the membrane potential is more negative than it is at rest

Refractory Period

time until another action potential can take place

Absolute Refractory Period

Na+ is closed and inactive; impossible for another to occur

Relative Refractory Period

greater stimulus needed to create another action potential

TTX and Novocain

What blocks action potential?

Saltatory Conduction

neuron depolarizes across the Nodes of Ranvier

Multiple Sclerosis

damaged myelin sheaths

Axodendritic

axon of one cell connects to dendrite of another cell

Axosomatic

axon of one cell connects to cell body (soma) of another cell

Axoaxonic

axon of one cell connects to axon of another cell

Exocytosis

neurotransmitters are released out of the cell

presynaptic membrane

Synaptic vesicles fuse with

Degradation

neurotransmitters are broken down by special enzymes

Physiological Psychology

studies the physiological mechanisms underlying behavior, often through direct manipulation and recording of the brain (of nonhuman subjects)

Psychopharmacology

studies how drugs affect the brain and behavior

Neuropsychology

studies the function (and dysfunction) of the nervous system, often by using a battery of tests to examine how behavior is affected by brain damage and disorders

Neuroanatomy

study of the structures of the nervous system

Neuro-endocrinology

study of interactions between the nervous system and the endocrine system

Neurochemistry

study of the chemical bases of the nervous system

Neuropathology

study of pathologies behind disorders of the nervous system

Neuropharmacology

study of the effects of drugs on the nervous system

Psychophysiology

uses physiological measures to study psychological processes in humans

Cognitive Neuroscience

study of the neural basis of cognition

Comparative Psychology

focuses on the biology of behavior in humans and other animals; combines ethology, evolutionary psychology, and behavioral genetics

How do we study experimentally?

Measure and manipulate

Central Nervous System

Brain and spinal cord

Peripheral Nervous System

Somatic/autonomic nervous systems

Human brain weight

2.86 pounds

Human brain number of neurons

86-100 billion neurons

Human brain energy percent

20-25% of total energy

Cerebral Cortex

outer covering of the cerebral hemispheres

Neurons

specialized cells that transmit information through an electrochemical process

Unipolar

neuron with one process extending from its body

Bipolar

neuron with two processes extending from its body

Multipolar

neuron with several processes extending from its body

Sensory Neurons

Carry signals from PNS into CNS

Motor Neurons

Carry signals from CNS into PNS

Interneurons

Carry signals within CNS

Glial cells

small, numerous, play supporting roles, do NOT transmit information

Schwann Cells

create myelin sheaths in PNS; guide axonal regeneration

Myelin sheath

insulation layer around axon

Oligodendrocytes

create myelin sheaths in CNS

Astrocytes

promoting synaptic formation, stabilizing blood-brain barrier, etc

Microglia

immune cells of the brain, respond to injury or disease

Cell Body (Soma)

headquarters of the neuron

Nucleus

contains DNA

Mitochondria

provides energy

Endoplasmic reticulum

fat and protein synthesis

Ribosomes

Protein synthesis

Golgi complex

packages molecules into vesicles

Microtubules

transport molecules, support the shape of the cell

Dendrites

receive and transmit signals from other neurons

Axon

long fiber where impulses are conducted

Presynaptic membrane

end of the axon that establishes a connection to another neuron

Postsynaptic membrane

receives information from presynaptic cell

Axon hillock

• junction of the cell body; where action potential begins

Nodes of Ranvier

gaps between the myelin; important for propagating the action potential

Terminal Buttons (boutons)

endings of the axon; release chemical messengers

Synapse

gap between neurons where communication occurs

Synaptic vesicles

located near the synapse; packages neurotransmitters

Membrane potential

neurons are filled with and surrounded by ions

Resting membrane potential

difference in electrical charge between the inside and outside of the cell when the neuron is at “rest”

Higher Outside

Sodium (+) and Chlorine (-)

Higher inside

Potassium (+)

Synaptic Integration

combinings all PSPs into one signal that determines whether a neuron fires an action potential

Post-synaptic potential

transmitter binds to receptors which contain channels for certain ions

Excitatory post-synaptic potential

increase in membrane potential following influx of +ions

Inhibitory post-synaptic potential

decrease in membrane potential following influx of -ions

Spatial Summation

 the sum of PSPs from different synapses

Temporal Summation

the sum of PSPs that are spaced closely in time

Diffusion and Electrostatic pressure

Two forces move Ions 

Diffusion

ions move from HIGH concentration….to LOW concentration

Electrostatic pressure

opposite ions attract and similar ions repel

Neuronal membrane

has channels that allow certain ions and other molecules to pass through the membrane

Sodium-Potassium Pump

sends 3 Sodium outside and brings 2 potassium inside