title: Dendritic glutamate-induced bursting in prefrontal pyramidal cells: role of NMDA and non-NMDA receptors.
abstract: OBJECTIVE
  To investigate whether in the prefrontal cortical (PFC) pyramidal cells, focal glutamate application to the apical dendrite induces bursting and whether the effect of glutamate involves activation of both NMDA and non-NMDA receptors.
  
  
  METHODS
  Pyramidal cells in layers V and VI of the PFC were visualized in rat brain slices using infrared videomicroscopy and recorded with whole-cell electrodes. Glutamate and its agonists were focally applied to the apical dendrite and the soma using microiontophoresis.
  
  
  RESULTS
  Dendritic glutamate application (0-20 nA, 10 mmol/L) induced repetitive bursts in most cells tested (12/17). In the same cells, somatic glutamate (5-20 nA, 10 mmol/L) induced only regular spiking. The bursting effect is likely to be direct since applications 5 microns away from the dendrite resulted in either a much reduced effect or no effect. Both CGP 37849 1 mumol/L and NBQX 1 mumol/L reduced the effect, suggesting an involvement of both NMDA and non-NMDA receptors. However, when non-NMDA receptors were selectively activated using AMPA (2-50 nA, 10 mmol/L), only regular spiking was observed. In contrast, selective NMDA receptor activation (NMDA 1.3-25 nA, 100 mmol/L) reliably induced bursting.
  
  
  CONCLUSIONS
  In most PFC pyramidal cells tested, dendritic glutamate application induces repetitive bursting, whereas somatic glutamate application induces only regular spiking. Both NMDA and non-NMDA receptors are activated during dendritic glutamate application. However, bursting is primarily mediated by NMDA receptors.
authors.affiliation: Department of Psychiatry, Yale University, School of Medicine, New Haven, CT 06520, USA.
authors.forename: X X
authors.initials: XX
authors.lastname: Zhang
authors.forename: W X
authors.initials: WX
authors.lastname: Shi
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D003712:Dendrites / Q000502:physiology; D018698:Glutamic Acid / Q000494:pharmacology*; D008297:Male; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors; D017397:Prefrontal Cortex / Q000502:physiology*; D017966:Pyramidal Cells / Q000502:physiology*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D011810:Quinoxalines; D016194:Receptors, N-Methyl-D-Aspartate; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; C064539:2-amino-4-methyl-5-phosphono-3-pentenoic acid; D018698:Glutamic Acid; D016202:N-Methylaspartate; D015763:2-Amino-5-phosphonovalerate; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid