Pt 5 Neurological Basis of Behavior

CNS

Central nervous System - consists of brain and spinal cords/nerve cord

PNS

peripheral nervous system - all aspects of the nervous system other than CNS.

can be divided into Sensory and Motor Division

Cell Body/Perikaryon

contains all of the basic organelles of an animal cell. located in the CNS

Dendrites

branching extensions of the cell. receptive in nature

Axons

singular extensions of the cell. distributive in nature

Myelin

allows for the faster transmission of information. produced by glial cells

Sensory/Afferent Neurons

respond to stimuli and send sensory information to the CNS for processing

motor/efferent neurons

carry motor information from the CNS to effector organs such as muscles and glands

interneurons

process sensory input and determine the appropriate motor response

Impulse/Action Potential

message of a neuron.

electrochemical signal conducted along the length of an axon due to the uneven exchange of sodium and potassium cations.

Synapse

where neurons exchange information with other cells

synaptic cleft

space b/w the two communicating cells

chemical synapse

electrical impulse causes chemicals to be released that will cross the cleft and propagate an impulse in the postsynaptic neuron.

a} These chemical signals are called neurotransmitters.

electrical synapse

the electrical impulse simply jumps the synaptic cleft.

a} Electrical synapses are less common.

Case Study: Cricket evasion of Echolocating Bats

interneuron INT-1 in crickets is necessary and sufficient for negative phonotaxis. aka avoiding bats

short term memories

can be retrieves for minutes, hours or a day after learning

intermediate term memories

can be retrieved days after learning. developed from strengthened short term memories

Long term memories

retrieved for months-years after learning. develop from strengthened intermediate memories

Case Study: Sea Hare Aplysia Californica

tested the formation of intermediate term memories

involuntary siphon withdrawal as defensive reflex when shot with fresh water, salt water, or alcohol

Key terms: habituation, sensitization, dishabituation

nonassosiative learning

change of the behavior of an animal due to an experience from specific kinds of stimuli. not associated with reinforcement or punishment

Long term potentiation (LTP)

stable and long lasting response to an action potential by the receiving neuron caused by rapidly repeated strong stimulation.

Strengthens connection b/w adjacent neurons. occurs in hippocampus

Long Term Depression (LTD)

lasting decrease in the responsiveness of the postsynaptic neurons after sensory neurons have received a slow repetition of stimuli.

mechanism that weakens the effectiveness of a synapse. occurs in hippocampus

synaptic remodeling

refinement of synaptic connections that occurs during memory formation through the development of new synapses and the eradication of less used synapses.

more synapse = more memory

Case Study: Song Learning in Zebra Finchneur

The study found that a brain region that is essential to the motor control of song also has an essential role in helping in auditory learning of the tutor song.

Key terms: sensory neurons, Zenk gene, motor neurons, interneurons

neurogenesis

creation of new neurons

sensory reflex

sensory neurons initiate activity in motor neurons

central pattern generator (CPG)

neural network that produce rhythmic patterned mot outputs without requiring sensory feedback

ex: breathing

motor command

sending out of impulse from the CNS to effector organs based on sensory input