Suckling Infant Rats Learn a Preference for a Novel Olfactory Stimulus Paired with Milk Delivery

Abstract

When presented a novel olfactory stimulus while suckling a passive dam, 11- to 14-day-old rat pups acquire a conditioned preference for that stimulus. The magnitude of the conditioned preference is greater if the pups received milk while suckling than if they did not. The results indicate that infants are capable of learning while suckling and that milk delivery plays a role in this associative process.

Behavioral and neural correlates of postnatal olfactory conditioning: II. Respiration during conditioning

“…The list includes: stroking (Pedersen, Williams, & Blass, 1982;Sullivan, Brake, Hofer, & Williams, 1986a;Sullivan, Hofer, & Brake, 1986b;Wilson & Leon, 1988b;Wilson et al, 1986, opiate injection (Kehoe & Blass, 1986), tailpinching (Sullivan et al, 1986b), milk ingestion (Brake, 1981;Johanson & Hall, 1982;Johanson, Polefrone, & Hall, 1984;Johanson & Teicher, 1980;Sullivan & Hall, 1988;Sullivan, McGaugh, & Leon, 1988a), norepinephrine injection (Pedersen et al, 1982;Sullivan & Leon, 1987b), suckling (Amsel, Letz, & Burdette, 1977;Kenny & Blass, 1977) and brain stimulation (Moran, Lew, & Blass, 1981). The ability of such a diverse group of stimuli to function as a reward in infant rats suggests that these stimuli share a common, perhaps nonspecific basis (Sullivan et al, 1986a(Sullivan et al, ,1986b.…”

“…Preweanling rats are capable of learning a preference for an odor that has been paired with a variety of stimuli (Brake, 1981;Johanson & Hall, 1982;Johanson & Teicher, 1980;Sullivan, Brake, Hofer, & Williams, 1986;). This learning is associated with an enhanced 14 C 2-deoxyglucose (2-DG) uptake in focal regions of the olfactory bulb glomerular layer in response to presentation of the preferred odor Sullivan & Leon, 1986;Sullivan & Leon, 1987a).…”

Huddling and independent feeding of neonatal rats can be facilitated by a conditioned change in behavioral state

“…Like milk, these stimuli cause pups to show behavioral activation; stimulated pups increase their activity, and display a number of fragmented behaviors resembling feeding, suckling, and sexual responses. As illustrated in the previous article , pairing a novel odor with any one of these activating stimuli can also change pups' preference for that odor when it is next encountered (also see : Alberts & May, 1984;Brake, 1981;Pedersen et al, 1982;Sullivan & Hall, 1985).…”

Maternal Behavior Their Adjustments and Implicated Factors

“…Factors proposed as mediating the handling effect include increased tactile stimulation from the dam and exposure to a different thermal environment of the laboratory conditions. In other study showed a marked difference in the durations of inter-nest-bout-intervals (IBIS), between bouts of at least 10 min duration, warm-nesting dams show longer IBIS [73] [74].…”