EXOGENOUS CALCIUM PROTECTS POSTWEANLING RATS FROM SALICYLATE-INDUCED CHANGES IN AUDITORY CONDITIONING

During Days 26-32 (postnatal), 18 rats drank more of a 0.05-M calcium- enriched solution when it was given to them ad lib or 1 h daily, but n ot when it was given 15 min daily, compared with 18 pups with similar access to plain water only. In a second experiment, acquisition and ex tinction of auditory conditioned suppression were observed in thirty-s ix 25-day-old pups, half of them reared with the calcium supplement th roughout gestation and preweanling, and the other half reared with tap water. Twenty-two hours before training, the subjects were fluid depr ived and exposed to continuous noise of 60 dB (SPL). Two hours prior t o each session, the subjects received either injections of sodium sali cylate before both sessions (n = 6 for each fluid type), saline before acquisition and salicylate before the extinction session (n = 6), or saline before both sessions (n = 6). Suppression of the approach to dr ink at the end of an alleyway paired the offset of the 60-dB noise and footshock. Calcium afforded subjects protection from salicylate-induc ed changes in auditory behavior during both acquisition and extinction .