Restriction of enhanced [2-14C]deoxyglucose utilization to rhinencephalic structures in immature amygdala-kindled rats.

Sixteen-day-old albino rat pups were kindled to varying degrees of seizure severity with amygdala stimulations spaced 15 to 20 min apart. Subsequently, each rat pup was injected (ip) with 10 microCi of [2-14C]-deoxyglucose, and received several additional kindled seizures at regular intervals throughout the following 80 min, at which time it was killed and processed for deoxyglucose autoradiography. Increased seizure severity was associated with correspondingly increased deoxyglucose utilization in many rhinencephalic limbic structures. However, unlike adults, rat pups did not show discernibly increased neocortical, thalamic, or substantia nigra utilization. We postulate that the apparent confinement of seizure activity to limbic structures in pups is related to their relative lack of postictal seizure refractoriness, as well as to other indices of increased seizure susceptibility in immature animals.