Biological Psychology and Neurotransmission

(Module 9)

Biology, Behavior, and Mind

Greek physician Hippocrates correctly located the mind in the brain.

Within little more than the past century, researches seeking to understand the biology of the mind have discovered that:

  • Our Adaptive brain is wired by our experiences
  • Among the body’s cells are nerve cells that conduct electricity and “talk” to one another by sending chemical messages across a tiny gap that separates them.
  • Specific brain systems serve functions
  • We integrate information processed in these different brain systems to construct our experience of sights and sounds, meanings and memories, pain and passion.

Neural Communication

Animals act so similarly that you could not distinguish between small samples of brain tissues from a human and a monkey.

Neurons

Neuron: A nerve cell; the basic building block of the nervous system.

Cell body: the part of a neuron that contains the nucleus; the cell’s life support center

Dendrites: a neuron’s often bushy, branching extensions that receive and integrate messages, conducting impulses toward the cell body.

Axon: the neuron extension that passes messages through its branches to other neurons or to muscle glands.

Myelin Sheath: a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.

Glial Cells: cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.

The more smart and complex an animal is, the more Glial Cells it has.

The Neural Impulse

Neurons transmit messages when stimulated by our senses or neighboring neurons.

Action Potential: A neural impulse; a brief electrical charge that travels down an axon.

Depending on the type of fiber, a neural impulse travels at speeds ranging from a sluggish 2 miles per hour to more than 200 miles per hour. %%But its top speed is 3 million times slower than that of electricity through a wire.%%

The brain is more complex than a computer, but at the same time it is much slower.

Threshold: The level of stimulation required to trigger a neural impulse.

Refractory Period: In Neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.

All-Or-None Response

  • There are times where your mind decides to not respond at all, or it does the complete opposite and it fires.
  • This is how a neuron works.

How Neurons Communicate

Neurons are so complicated and intricate that even with a microscope you would have trouble seeing where one ends and another begins.

Synapse: The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.

  • There is a tiny gap at this junction called Synaptic Gap or Synaptic Cleft

Neurotransmitter

Neurotransmitter: Chemical messengers that cross the synaptic gaps between neurons. They decide if the neuron will generate a neural response.

Reuptake: A neurotransmitter’s re-absorption by the sending neuron.

A particular brain pathway may use only one or two neurotransmitters, such as serotonin and dopamine, and particular neurotransmitters affect isolation; they interact, and their effects vary with the receptors they stimulate.

This is why people love pain killers, they essentially shut down the neurotransmitters that are signaling the brain that they are in pain.

Antagonists: A molecule that inhibits or blocks a neurotransmitter's action.

%%(Pages 85 - 89) Helps with Re-Uptake, Closure, and Synapse functions.%%

  • 88 talks about Drugs. Pain killers can block the synapse from happening as much.