title: Effect of NMDA on the activity of cortical glutaminergic structures in delayed visual differentiation in monkeys.
abstract: The effect of intracortical perfusion with the glutamate agonist NMDA on visual recognition and short-term memory, as well as an on the responses of visual cortex neurons, were studied in rhesus macaques. A microdialysis technique was used in combination with multichannel microelectrode recording of single cortical cells in the immediate vicinity of the dialysis tube in a behavioral experiment in which the monkey had to solve a task involving delayed visual differentiation of stimuli of different colors. NMDA altered the characteristics of recognition in monkeys. The duration of information storage in short-term memory was increased significantly (2-4-fold), and there was a significant reduction in the motor response time for all delay periods. These changes were accompanied by a significant rearrangement of neuron activity in the visual cortex at all stages of the behavioral task. At different stages of the task, 70-85% of the neurons showed 2-5-fold increases in activity, while 6-20% showed reductions in activity. These results demonstrate an involvement of visual cortex glutaminergic structures in the process of visual recognition and short-term memory, as well as a nootropic effect obtained by intracortical administration of NMDA.
authors.affiliation: Laboratory for the Regulation of Brain Neuron Function, I. P. Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg.
authors.forename: K N
authors.initials: KN
authors.lastname: Dudkin
authors.forename: V K
authors.initials: VK
authors.lastname: Kruchinin
authors.forename: I V
authors.initials: IV
authors.lastname: Chueva
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D003071:Cognition / Q000502:physiology; D004567:Electrodes, Implanted; D004594:Electrophysiology; D018690:Excitatory Amino Acid Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D018698:Glutamic Acid / Q000502:physiology*; D008253:Macaca mulatta; D008570:Memory, Short-Term / Q000187:drug effects; D017551:Microdialysis; D016202:N-Methylaspartate / Q000008:administration & dosage / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000187:drug effects*; D011930:Reaction Time / Q000502:physiology; D014793:Visual Cortex / Q000166:cytology / Q000187:drug effects*
chemical_list: D018690:Excitatory Amino Acid Agonists; D018698:Glutamic Acid; D016202:N-Methylaspartate