Normalization of spatial learning despite brain damage in rats receiving ketamine after seizure-induction: evidence for the neuromatrix.

The concept of the neuromatrix assumes that all behaviours are associated with complex spatiotemporal electromagnetic fields within the brain. The same complex magnetic field can be supported potentially by different mosaics of neuronal associations and result in the same behaviours. In the present study the accuracy of long-term and short-term spatial memory for rats that had been treated with 100 mg/kg of ketamine immediately after the induction of seizures by lithium and pilocarpine did not differ from normal rats despite the conspicuous multifocal neuronal loss. A 30-min. delay of treatment with ketamine resulted in significant memory impairment. Whereas deficits in short-term memory were significantly correlated with cell loss within the CA field of the hippocampus, deficits in long-term memory were related to cell loss within specific thalamic-amygdaloid structures. Implications for the concept of the neuromatrix, if valid, are discussed.