DMD Conditioned Flavor Preference Glucose Dose

Investigators: Mukherjee, Houpt

Protocol: 1917

Purpose

Attempt single-bottle single trial conditioning using a CS+ which is iso-preferred to water (Kool-Aid + 0.05% saccharin, based on Golden data from experiment GI -- see chapter 3 of Golden's dissertation).

Will also characterize a US dose response using 0,4, or 8% glucose to determine a range of conditioning strengths (since KA + 0.2% saccharin + 8% glucose looks too strong to see any modulation by eg sodium buytrate).

Agenda

n=18 male and female rats (TH-GFP rats from Trombley). Male and female alternate even and odd id numbers (CHECK which is which). 3 groups: 0% glucose US (rats DMD01-06), 4% glucose US (rats DMD07-12), and 8% glucose US (rats DMD13-18)

Baseline

• Placed on food and water restriction

Daily routine:

• Rats weighed.
• give measured ration of chow to maintain 90% initial bodyweight
• given 30 min access to water vs 8% maltodextrin (2 bottles) from 2pm to 230pm
• bottle sides alternated each day

Continue baseline until latency to drink and intakes are stabilized.

Notes: use maldodextrin to encourage consumption, and 2 bottles to train to make choice. Start chow ration at 25g, then adjust to maintain ~90% of baseline weight

Conditioning Day

• CS+ = 0.05% Kool-Aid + 0.05% saccharin
  • in 4 liters, 2 g Cherry Kool-Aid + 2 g sodium saccharin

• US = glucose at 0, 4 or 8%
  • 4% = 80g glucose / 2 liters
  • 8% = 160g glucose / 2 liters

Conditioning Procedure:

• Weigh rats.
• 30 min access to CS+/glucose = 0.05% Kool-Aid + 0.05% saccharin + either 0% glucose, or 4% glucose, or 8% glucose.
• At end of 30 min access, return ad lib food and (weighed) water.

Extinction Tests

24 h after conditioning, Two Bottle Preference Tests of CS+ vs water are begun for at least 6 (?) days

• Weigh rats.
• 2 bottles with 24 h access:
  • bottles weighed and refilled daily
  • water
  • CS+ = 0.05% Kool-Aid + 0.05% saccharin
    • in 4 liters, 8 g Cherry Kool-Aid + 2 g sodium saccharin
• alternate bottle sides each day
• ad lib access to chow throughout