David Pittman, Ph.D.
pittmandw@wofford.edu

LIVE LAB WEB CAM

     
current research projects
  behavioral studies  
There are three ongoing lines of behavioral research in our laboratory:
The use of conditioned taste aversions to characterize the detection thresholds and discriminative capabilities for free fatty acids in a Sprague-Dawley rat model.  

Previously, we have demonstrated that rats can detect and avoid linoleic acid and oleic acid during 2-bottle preference tests the day after receiving a conditioned taste aversion (CTA) pairing of the consumption of either linoleic or oleic acid followed by an i.p. injection of lithium chloride which causes gastric distress.  We hypothesize that rats may be using orosensory cues in the detection and avoid of the free fatty acids.  This project seeks to minimize the role of olfaction and post-ingestive cues through short-stimulus testing of licking behavior in the Davis Rig apparatus following a CTA pairing with linoleic or oleic acid.  Use of short-stimulus (8-30s) testing allows the licking behavior to multiple concentrations of the conditioned stimulus as well as other potentially associated stimuli to be assessed. 
Click here to view our recent publication that used this methodology to identify the detection thresholds of free fatty acids and the ability to form generalized avoidances across free fatty acids.

The effect of adding free fatty acids to other taste solutions on the consumption patterns of appetitive and aversive taste stimuli.
Given that rats can detect very small quantities (88 micromolar) of linoleic acid and oleic acid, it is thought that these free fatty acids may be a 'tastable' chemical component of fats such as corn oil. Adding a fat (corn oil) to taste solutions will increase the consumption of the solution by a rat. The proposed transduction mechanism of free fatty acids (delayed-rectifying potassium channels) would support the hypothesis that free fatty acids may enhance the intensity of concomitant taste stimuli.  In this study, solution intake is measured in a Davis Rig apparatus which has a shutter that opens and closes to allow a discrete access time, typically 8-30 seconds, during which the rat can lick a bottle spout of up to 16 different solutions.  A computer controls the presentation of each solution and measures the number of licks during each trial.
Click here to view our recent publication that established consumption patterns for varied concentrations of appetitive (sweet) and aversive (salty, sour, & bitter) tastants and then measured the effect of adding free fatty acids to the taste solutions.

The effect of the benzodiazepine chlordiazepoxide (CDP aka Librium) on the ingestion of sweet, sour, salty, and bitter tastants.
Evidence suggests that benzodiazepines such as CDP act to increase the palatability of taste stimuli.  We are exploring the effects of CDP administration on taste through brief access (<30s) and long-term (>30min) stimulus testing of sweet, sour, salty, and bitter taste solutions.  This research is a collaboration between the Pittman laboratory at Wofford College and the laboratory of Dr. JP Baird at Amherst College. Check back soon for updates on this new line of research.

When we are collecting data, click here to view the live web cam from inside the Davis Rig testing chamber!

nerve transection studies  
Having shown that Sprague-Dawley rats can detect and avoid free fatty acids following a CTA, we seek to identify the afferent neural signals that permit this detection and avoidance.  One method of identifying necessary and sufficient afferent neural pathways involves compromising the system through selective nerve elimination.  We have begun a series of experiments combining the CTA detection of free fatty acids with the systematic elimination of the three gustatory nerves.  Click here to view our recent publication that implicates the chorda tympani afferent taste nerve as transmitting information about free fatty acids from the tongue to the brain.

electrophysiological recordings  
Representing the latest addition to our facilities, we plan to commence neural recordings of afferent gustatory signals during oral cavity stimulation by free fatty acids.  Preliminary evidence from our nerve transection studies suggests that the chorda tympani nerve plays a role in the ability of rats to avoid linoleic acid following a CTA.  Whole-nerve recordings of the chorda tympani nerve combined with multi-unit and single-unit recordings in the geniculate ganglion will be used to characterize any afferent neural response to linoleic acid stimulation of the oral cavity.

See our research facilities for additional information.

     

Please use the below links to explore our work:
  summary research
 statement
current research
projects
 
  free fatty acid
 publications
free fatty acid
 presentations
 
  research facilities people  

Return to Dr. Dave Pittman's web site

     
 

The laboratory of Dr. Dave Pittman
Associate Professor of Psychology, Wofford College
429 N. Church Street, Spartanburg, SC  29303