1 / 18

SENSORY PHYSIOLOGY

SENSORY PHYSIOLOGY. BIOLOGY 305 LABORATORY. LAB PRACTICAL. Be Sure YOU Know: How to log on How to load software & settings (tutorial) How to set up hardware How to use the finger pulse transducer (w/o noise) How to define Aliasing and how to avoid it

prisca
Télécharger la présentation

SENSORY PHYSIOLOGY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SENSORY PHYSIOLOGY BIOLOGY 305 LABORATORY

  2. LAB PRACTICAL • Be Sure YOU Know: • How to log on • How to load software & settings (tutorial) • How to set up hardware • How to use the finger pulse transducer (w/o noise) • How to define Aliasing and how to avoid it • How to define the Nyquest Frequency • How to determine a sufficient sampling rate • How to explain differences between analog & digital signals • How to change the display time/resolution (zoom) • How to place marks in the record • How to define & calculate: Period, Frequency, HR (+ units) • How to analyze a trace in the Analysis Window • How to print & use the Journal

  3. LAB PRACTICAL • How You Loose Points: • Forgetting to turn on iworx box • Noisy trace • Needing assistance from TA • Not completing exercise on time • Errors in calculations & equations • Omitting units

  4. THIS WEEK: REFLEX & REACTION TIMES Stimulus – Response Pathways: * Stimulus  * Receptor  * Afferent Path  * CNS  * Efferent Path  * Effector  * Response!

  5. THIS WEEK: REFLEX & REACTION TIMES • Investigation of Reaction Times: • Audio Stimuli • Prompted & Patterned Sounds • Visual Stimuli

  6. THIS WEEK: REFLEXES & REACTION TIMES Investigation of Reaction Times: • Possible Influences: • Number of neurons in afferent path • Number of synapses • Distance between stimulus and sensory part of brain • Presence of mylinated axons in pathway • Diameter of neurons in pathway • Amount of processing & integration in CNS • Efferent pathway NOT a likely influence

  7. THIS WEEK: REFLEX & REACTION TIMES • Reflex: • Stereotypical, rapid motor response • Does not require input from brain --HOWEVER-- • Brain can exert descending inhibition & dampen reflex

  8. NEXT WEEK:THE CRAYFISH STRETCH RECEPTOR CRAYFISH: • Invertebrate in phylum Arthropoda • subphylum Crustacea • Also includes: barnacle, crab, crayfish, lobster, shrimp • Scientific name: Procambarus clarkii • Largely aquatic • Characteristics include: • Hard exoskeleton • Jointed, paired appendages • Three body regions • head • thorax • abdomen

  9. THE CRAYFISH STRETCH RECEPTOR Crayfish Nervous System: • Bilateral Symmetry • Segmented Arrangement: • Each body segment contains a ganglion • Axons carry info between ganglia • Nerve roots branch off ganglia to periphery • Contain sensory & motor neurons

  10. THE CRAYFISH STRETCH RECEPTOR Purpose of Exercise: • Gain experience w/ classic neurophys. prep. • Investigate stimulus-response properties of crayfish nervous system • Observe characteristics of crayfish sensory system • Encoding of stimuli • Sensory adaptation • Differentiate responses from two types of sensory organs

  11. THE CRAYFISH STRETCH RECEPTOR Muscle Receptor Organs (MROs): • Located in abdomen • Composed of a sensory neuron & an associated muscle • Superficial Extensor Muscle • Sensory neuron has stretch-sensitive dendrites embedded in the muscle • Two types: MRO1 & MRO2

  12. THE CRAYFISH STRETCH RECEPTOR Superficial Extensor Muscle: • Two per abdominal segment • One on each side • Each contains 2 MROs, • One of each type

  13. THE CRAYFISH STRETCH RECEPTOR When Abdomen of Crayfish Bends: • S. extensor muscle is stretched • Sensory neuron receptors activated

  14. THE CRAYFISH STRETCH RECEPTOR Signaling: • Graded potentials (GP) generated by stretch sensitive dendrites • Ion channels • Action potentials (APs) produced at spike-initiating zone

  15. THE CRAYFISH STRETCH RECEPTOR For This Exercise: • We’ll record extracellularly from nerves that carry sensory info from MROs to CNS • Accomplished by curling crayfish tail to stimulate sensory receptors

  16. THE CRAYFISH STRETCH RECEPTOR Major Instruments: • Suction Electrode • Micromanipulator • Dissecting Scope

  17. THE CRAYFISH STRETCH RECEPTOR Major Instruments: • Amplifier • Digitizer (iWorx Unit) • Computer (LabScribe) • Audio Amplifier

  18. THE CRAYFISH STRETCH RECEPTOR Exercises: • Tapping Experiment • Elicit MRO1 & MRO2 • Increasing Stimulus Intensity • Observe MRO1 responses (freq) to sm, med, and large stimuli (stretch) • Adaptation Experiment • Observe responses to a stimuli of long duration and fixed intensity

More Related