Expts

A list of experiments in progress :

1/25/07 Serine Racemase and NR2B in situ hybridization

Davenport. Pilot examination of SR and NR2B mRNA expression in gustatory cortex and amygdala. One rat given ~16-h access to 0.125% saccharin, control rat just water.

1/15/07 Extinction of saccharin and NaCl-LiCl CTA in female rats (Expt PI)

Smith, Ortega, Janowitz, Muller. Folow-up experiment to "stacked rats" paper, as suggested by reviewer. After saccharin-magnet pairing, CTA in female rats does not readily extinguish. This expt tests 2 different CS's (saccharin vs. NaCl) using a different US (LiCl). Female rats (n=32) will be conditioned against either 0.125% saccharin or 0.45% NaCl (10 min access) paired with LiCl (12 ml/kg) immediately after CS.

1/8/07 Sucrose/NaCl CTA two-bottle discrimination (Expt SO)

Ortega. Follow-up experiment to experiment SN, which is follow-up to Howard's taste specificity in short-term CTA. Male rats (n=12) will be conditioned against 5% sucrose or 75 mM NaCl paired with LiCl (12 ml/kg) immediately after access, then given two bottle preference tests: Sucr vs NaCl, Sucr vs water, and NaCl vs water. Results Rats showed clear discrimination such that CS- was preferred over CS+ and water for both sucrose and NaCl. there was a funny order effect in Sucrose CTA rats, however, in that if first tested with Sucr vs NaCl (i.e. before a sucrose v water and NaCl v water tests), the Sucrose CTA rats did not drink either sucrose or NaCl.

1/5/07 GLP-1 and Serine Racemase RT-PCR

Davenport, Ortega. From male sprague-dawley rat, dissected gustatory cortex, cerebellum, hypothalamus, amygdala, and hippocampus/cortex for RNA extraction by Trizol. Will perform RT-PCR for serine racemase (RD) and GLP-1R receptors (BO). Results: The serine racemase Rt-PCR worked great, the GLP-1R did not. Will redesign the primers for future experiment.

12/06-2/07 c-Fos induction after Conditioned Flavor-Taste Preference Expression

Golden, Ortega, Kwon (taught COC). Rats given a CFTP by several days of 24-h access to kool-aid, alternating solutions in high concentration saccharin (preferred, CS+/US+) or low concentration of saccharin (non-preferred, CS+/US-.) CFTP is tested by 24-h 2-bottle preference between CS+/US- vs CS-/US-. Intraoral catheters were implanted. After 3 days of water infusions, rats were infused (10 ml /10 min)with either US+, CS+/US-, CS-/US-, or a novel kool-aid flavor. One hour later, rats were prefused. Olfactory bulb, gustatory cortex, amygdala, PBN, and NTS were processed for c-Fos.

11/06-2/07 Swimming in Circles induced by Magnetic Field Exposure in Mice

CE Houpt, Smith (asst by Ortega, Janowitz, Muller) Male mice (C57/BlJ) were restrained and exposed 3 at a time to 14.1 T magnetic field for 30-min, or sham-exposed. Mice were then placed in center of a 2-m diameter swimming pool for a 2-min swim test. Magnet and sham-exposed mice were tested 0, 10, or 20 min after the end of restraint. Magnet-exposed mice and 0-min sham-exposed mice were retested at 24-h to detect persistent deficits in swimming. CEH working on Mac application to quantify rotation of mice from quicktime video.