Effects of CNS Manipulations on Seizures Induced by Monomethylhydrazine Administration in the Cat: Spinal Lesions
Abstract
This investigation examined the effects of dorsal column lesions on electrocortical activity and susceptibility to monomethylhydrazine induced seizures in cats. Eleven animals, prepared with indwelling cortical electrodes over hind-limb and forelimb projection areas of somatosensory cortex, received bilateral lesions of the dorsal columns at either high (C1-C3) or low (C5-T1) cervical levels. After a three week postsurgical period, each animal was administered a convulsive does of monomethylhydrazine. Seizure latency was measured from the time of drug injection to the onset of tonic-clonic convulsions. Latency data were compared with those from intact animals (N=18). Comparable pre- and post-lesion EEG recordings were subjected to bandpass filter analysis. Results indicated a progressive and significant increase in seizure latency with more encephalad dorsal column transection. Further, EEG data showed significant post-lesion enhancement of 12-15 Hz sleep spindle activity over sites corresponding to peripheral receptive fields below the level of the lesions. These findings show that reduced susceptibility to seizures provided by spinal interruption of somatosensory pathways is associated with enhancement of EEG spindle activity over sensorimotor cortex. A similar facilitation of these EEG patterns is seen with chemical and behavioral manipulations known also to provide protection against generalized seizures, suggesting that the release of intrinsic thalamocortical activity may be a common factor in protection against MMH induced seizures.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1981
- Accession Number
- ADA098148
Entities
People
- M. B. Sterman
- S. S. Bowersox
Organizations
- UCLA David Geffen School of Medicine