strychnine and Ischemic-Attack--Transient

The observation of Xu et al. concerning reduction in latency of the visual evoked responses (VER) following cortical cryogenic injury, prompted us to ascertain whether similar VER changes could be demonstrable after ischaemic brain injury, especially, since both conditions have in common involvement of neuroexcitatory mechanisms. In our study, the Mongolian gerbils, which were subjected to 10 min bilateral carotid occlusion ischaemia, revealed decreased latency of the VER, with the peak of latency reduction between 4 and 7 h. An almost immediate decrease in VER latency was observed when glutamate was directly applied to the pial surface of the brain. These observations indicate that the reduction of VER latency may be related to neuroexcitation induced by release of excitatory amino acids, the latter constituting a widespread phenomenon, concomitant with brain injuries of various aetiologies.

Topics: Animals; Brain; Cerebral Cortex; Electroencephalography; Evoked Potentials, Visual; Gerbillinae; Glutamates; Glutamic Acid; Ischemic Attack, Transient; Strychnine; Time Factors

Topics: Animals; Blood Pressure; Cerebrovascular Circulation; Electroencephalography; Ischemic Attack, Transient; Oxygen; Pentylenetetrazole; Rabbits; Seizures; Strychnine

Topics: Acetylcholine; Animals; Brain Chemistry; Cerebral Cortex; Dogs; Electroencephalography; Electrophysiology; Ischemic Attack, Transient; Perfusion; Strychnine; Time Factors

Topics: Animals; Asphyxia; Cerebral Arteries; Cerebral Cortex; Female; Ischemic Attack, Transient; Male; Muscle, Smooth; Rabbits; Seizures; Strychnine

Topics: Acetylcholine; Animals; Cerebral Cortex; Dogs; Evoked Potentials; Ischemic Attack, Transient; Strychnine