The role of the pyriform cortex in the generation of interictal spikes in the kindled preparation

Brain Res. 1988 Jun 28;454(1-2):251-63. doi: 10.1016/0006-8993(88)90825-6.


The development of interictal spikes (IIS) was monitored during amygdala or pyriform cortex kindling in a series of 4 experiments. It was found that (1) spike-like transients were often present in the pyriform cortex EEG before kindling had begun; (2) these transients developed progressively into large amplitude and complex IIS as kindling proceeded; (3) the pyriform cortex IIS continued to show the greatest proportion of earliest onset spikes in most animals after kindling was completed; (4) other sites (including the ventral, but not the dorsal hippocampus) gradually developed the capacity to generate IIS as kindling progressed; (5) although specific sites within the pyriform cortex may serve as a generator, their location along the longitudinal axis of the pyriform lobe varied from animal to animal (and did not appear to depend upon the location of the kindling electrode); (6) although there often appeared to be 2 spike types, based on the polarity of the first component, there were also transitional waveforms, raising the possibility that they were variations on a single spike type, and (7) the IIS were often preceded, usually in the pyriform cortex, by reliable pre-spike events (smaller spikes or a 'ripple' on the EEG).

MeSH terms

  • Amygdala / physiopathology*
  • Animals
  • Cerebral Cortex / physiopathology*
  • Electric Stimulation
  • Evoked Potentials
  • Kindling, Neurologic*
  • Rats