Transcript 2 nd MIDTERM EXAM

PART 3: MOTOR STRATEGIES
SUMMARY
 CH5: mate calling in crickets
 CH6: flight in locusts
 CH7: escape behavior in crayfish
SUMMARY: MOTOR STRATEGIES
 cancellation
 suppression / cancellation of competing signals
 e.g., crayfish tailflip circuitry – trigger of giant fiber
 activates fast flexion circuitry
 cancels extension & other postural responses
 e.g., locust – flight
 excitatory signals  wing elevators
 inhibitory signals  wing depressors
 reciprocal inhibition
SUMMARY: MOTOR STRATEGIES
 proprioception
 1 of 2 classes of sensory input  motor systems
(the other is exteroceptor)
 feedback from biomechanical system being
driven
 e.g., locust – flight, 3 classes give info about
 position
 degree of activation
SUMMARY: MOTOR STRATEGIES
 response topography
 behavior can be multidimentional
 duration of stimulus  magnetude of behavior is
1 type of relationship we can consider
 input – output feature of behavior
 eliciting stimulus can  behavior that is
 graded, e.g., locust – tegulae / wing hinge
 all-or-none, e.g., crayfish tailflip
 reflect neuronal architecture of system
SUMMARY: MOTOR STRATEGIES
 central pattern generators (CPGs)
 underlies most rhythmic circuits  behavior
 all 3 examples in part 3
 does not rely on phasic sensory feedback
 no timing or patterning information in trigger
 CPG neurons must be
 rhythmically activated
 appropriately connected in system
 must pass reset test
 some peripheral neurons also part of CPG system
 e.g., locust – proprioceptors
 CRG = stable oscillatory core CPG + peripheral input
SUMMARY: MOTOR STRATEGIES
 shared circuitry
 overlap in neural circuits
 all 3 examples in part 3
 e.g., cricket – wings for flight, song, courtship
 motor neural circuits can be reconfigured by
modulatory influences  adaptive behavior
SUMMARY: MOTOR STRATEGIES
 sequence integration
 feed-back & feed-forward mechanisms
 proper integration of behavior in space & time
 cancellation is 1 such mechanism
 e.g., locust – DDN signals gated by CPG
 behavior occurs in context of other motor activity
 e.g., cricket – wings elevated for stridulation
 actions integrated with ongoing behavior 
adaptive output
2nd MIDTERM EXAM
 written, 15% of final grade
 assigned (web page) @: 6 pm T.3.27
 due (eMail) @: 3 pm R.3.29
 send to: [email protected]
 subject line: e2 lastname,initial (e2 Smith, J)
 attach: MS word document only
 file name: e2 lastname initial.doc (e2 Smith J.doc)
2nd MIDTERM EXAM
 3 questions, answer them all
 use proper English sentences
 maximum 200 words / question
 you need to be concise & efficient
 organize ideas into sections (no headings)
 introduction (1 sentence)
 body (~4 – 8 sentences)
 conclusion (1 sentence)
 references (not included in word count)
2nd MIDTERM EXAM
 where should you get your information?
 text book, lecture notes
 other literature
 not the web
 discussion of your ideas with others is encouraged
2nd MIDTERM EXAM
 how should you write your answers?
 your ideas, in your own words
 sentences or even parts of sentences may not
be lifted verbatim from…
 any source (including me)
 any other student in the class
 this will be controlled electronically
2nd MIDTERM EXAM
 suggested strategy
 collect relevant literature
 read several times, make plenty of notes
 identify critical ideas for addressing the question
 assemble ideas in logical order
 make an outline… determine what the content of
each sentence will be
 write a rough draft… take a break
 write at least two more revisions... send it
2nd MIDTERM EXAM
 how should you site your sources?
 ideas are referenced in text… e.g., “Parallel processed
auditory signals are reassembled in the auditory cortex of the owl (1).”
 at the end of each answer, list each sited piece of
literature, in the order they were used, as follows:
 books: 1. Smith, J. and Jones, S. (2006) Owls, Prentice Hall, New
York, pp. 345-347.  pages where info was taken
 chapters: 1. Smith, J. (2006) Auditory neurobiology of Barn Owls, in
Owls (Jones, S., ed.), Prentice Hall, New York, pp. 32-74.
 papers: 1. Smith, J. and Jones, S. (2006) Owls, Nature, 432, 123-8.