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Biology 444: Sensory Biology

Sensory Biology is a discipline in which we attempt to gain an understanding of how organisms extract information from their environment.  One of the key characteristics of life is the ability to respond to environmental stimuli.  Organisms must be able to interface with the stimulus, transduce the information into a neural signal ,interpret the neural input, and initiate behavioral responses that are appropriate to the stimulus.  This course will focus on each aspect ofthis process for each sensory modality.  The discussion of a sensory system will begin with the physical nature of the stimulus (sensory systems will be divided into chemical, mechanosensory, and electromagnetic senses).  This will be followed by the biological interface between the stimulus and the receptor organ, and will focuson the physics of stimulus detection.  Then the transduction and neuralencoding of the stimulus will be discussed, followed by discussions on central projections, behavioral outputs (psychophysics), and artificial sensory systems.  Thus the course will encompass a broad spectrum of biological disciplines (biophysics, anatomy, neuroscience, psychophysics, and artificial intelligence) using sensory systems as a unifying theme.  In addition, the class will engage in discussions on the ecological and evolutionary constraints on sensory system design.
To simplify the scope of the course, material will center on the sensory biology of terrestrial vertebrates, with occasional comparisons to systems found in aquatic animals (when relevant).


Upon completion of this course,students will be expected to:

o Enumerate and characterize the four basic aspects of stimuli: quality, intensity, spatial distribution, and temporal properties, and how they differ across stimulus modalities.
o Describe the wave properties of matter and their relevance for mechanosensory and electromagnetic senses.
o Demonstrate an understanding of how each sensory stimulus interacts with biological structures of the different sensory modalities.
o Describe the process of sensory transduction for each major sense.
o Discuss how aspects of stimuli are represented in a neural code.
o Discuss how specific psychophysical phenomena arise as a result ofstimulus transmission, reception, and/or central processing.
o Outline the basic principles behind designing artificial sensoryorgans.
o Discuss the ecological and evolutionary constraints on sensory systemdesign

Students will require a basicknowledge of biology and physics and would thus need Biology 141, 142, and 245, and Physics 120 and 121 (or concurrent enrollment with Physics 121).  Students with background in other physics courses may takethe course with the permission of the instructor.

Sample Syllabus:

1 Course introduction and introduction to signal detection theory
2 Aspects of sensory stimuli: quality, intensity, spatial, and temporalproperties
3 Introduction to cell signal transduction; properties of chemical stimuli
4 Olfaction: peripheral mechanisms and transduction, and centra projections
5 Olfaction: psychophysics and chemical communication; artificial noses
6 Vomeronasal system and pheromones
7 Trigeminal chemoreception and cutaneous chemical detection
8 Taste: peripheral mechanisms, transduction, central projections, and behavior
 ***** EXAM I *****
9 Wave theory and stimulus transmission
10 Sound waves: generation, propagation, and sound frequencies
11 The cochlea and hair cells
12 Central projections and sound-mediated behavior
13Vestibular system, balance, and proprioception
14 Tactile system
15 Touch in other systems: lateral lines, mechanosensory hairs; artificial sensors
 ***** EXAM II *****
16 Properties of light: the electromagnetic spectrum, color, polarization
17 Properties of light II: lenses and optics, and the optical properties of eyes
18 The vertebrate retina and the physiology of photoreceptor cells
19 Processing in the outer and inner plexiform layers of the retina
20 Central processing of visual stimuli
21 Visual mediated behaviors and capabilities; disorders related tovision
22 Electric and Magnetic senses
 ***** EXAM III *****
23 & 24  Integration of Sensory Biology principles

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