PMID- 11713626
OWN - NLM
STAT- MEDLINE
DCOM- 20020111
LR  - 20131213
IS  - 0014-4819 (Print)
IS  - 0014-4819 (Linking)
VI  - 141
IP  - 2
DP  - 2001 Nov
TI  - Epileptiform activity in the nucleus accumbens induced by GABA(A) receptor 
      antagonists in rat forebrain slices is of cortical origin.
PG  - 146-52
AB  - Extracellularly recorded field potentials, evoked by stimulation of 
      cortico-nucleus accumbens border, were recorded in the nucleus accumbens (NAcc) 
      in horizontal slices of rat ventral forebrain. The field excitatory postsynaptic 
      potential (EPSP) event (N2) was calcium dependent, blocked by tetrodotoxin (1 
      microM), and reduced by over 70% by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) 
      (10 microM), the antagonist of AMPA-type glutamate receptors. The EPSP amplitude 
      was enhanced by either of the GABA(A) receptor antagonists, picrotoxin (10 
      microM; by 252+/-33%, n=18) and bicuculline methiodide (20 microM; by 216+/-34%, 
      n=4). Additionally, picrotoxin (3-50 microM) and bicuculline methiodide (20 
      microM) promoted epileptiform activity within the NAcc, manifest as the emergence 
      of additional late components, N3, N4 and N5, in the evoked synaptic waveform. In 
      slices with the frontal cortex removed, picrotoxin (10-50 microM) and bicuculline 
      methiodide (20 microM) were unable to promote epileptiform activity within the 
      NAcc, although a smaller increase in the peak amplitude of the field EPSP 
      (163+/-18%, n=6) was observed at the highest concentrations of picrotoxin (50 
      microM). Histological examination of the slice demonstrated that in such 
      decorticated slices, the piriform cortex (PC) had been removed. We propose that 
      stimulation of the cortico-NAcc border not only evokes an orthodromic EPSP in the 
      NAcc, but also causes antidromic activation of cortical tissue. Disinhibition by 
      GABA(A) antagonists of circuits intrinsic to the cortex, possibly the piriform 
      cortex, is the principal cause of the facilitation of the EPSP and of 
      regenerative epileptiform activity in NAcc evoked by stimulation of cortical 
      input.
FAU - Buckby, L E
AU  - Buckby LE
AD  - Department of Pharmacology, Division of Neuroscience, The Medical School, 
      University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT, UK.
FAU - Lacey, M G
AU  - Lacey MG
LA  - eng
PT  - Journal Article
PL  - Germany
TA  - Exp Brain Res
JT  - Experimental brain research
JID - 0043312
RN  - 0 (Excitatory Amino Acid Antagonists)
RN  - 0 (GABA Antagonists)
RN  - 0 (GABA-A Receptor Antagonists)
RN  - 0 (Receptors, AMPA)
RN  - 0 (Receptors, GABA-A)
RN  - 0 (Receptors, N-Methyl-D-Aspartate)
RN  - 3KX376GY7L (Glutamic Acid)
SB  - IM
MH  - Animals
MH  - Cerebral Cortex/cytology/drug effects/*metabolism
MH  - Cerebral Decortication
MH  - Electric Stimulation
MH  - Epilepsy/chemically induced/metabolism/*physiopathology
MH  - Excitatory Amino Acid Antagonists/pharmacology
MH  - Excitatory Postsynaptic Potentials/drug effects/*physiology
MH  - GABA Antagonists/pharmacology
MH  - GABA-A Receptor Antagonists
MH  - Glutamic Acid/metabolism
MH  - Male
MH  - Neural Inhibition/drug effects/*physiology
MH  - Neural Pathways/cytology/drug effects/*metabolism
MH  - Neurons/drug effects/metabolism
MH  - Nucleus Accumbens/cytology/drug effects/*metabolism
MH  - Rats
MH  - Rats, Wistar
MH  - Receptors, AMPA/antagonists & inhibitors/metabolism
MH  - Receptors, GABA-A/*metabolism
MH  - Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors/metabolism
MH  - Synaptic Transmission/drug effects/*physiology
EDAT- 2001/11/20 10:00
MHDA- 2002/01/12 10:01
CRDT- 2001/11/20 10:00
PHST- 2001/01/31 00:00 [received]
PHST- 2001/06/13 00:00 [accepted]
PHST- 2001/11/20 10:00 [pubmed]
PHST- 2002/01/12 10:01 [medline]
PHST- 2001/11/20 10:00 [entrez]
AID - 10.1007/s002210100841 [doi]
PST - ppublish
SO  - Exp Brain Res. 2001 Nov;141(2):146-52. doi: 10.1007/s002210100841.