Abstract
We studied the impact of transmitter release resistant to tetrodotoxin (TTX) in morphologically identified neocortical pyramidal neurons recorded intracellularly in barbiturate-anesthetized cats. It was observed that TTX- resistant release occurs in pyramidal neurons in vivo and at much higher frequencies than was previously reported in vitro. Further, in agreement with previous findings indicating that GABAergic and glutamatergic synapses are differentially distributed in the somata and dendrites of pyramidal cells, we found that most miniature synaptic potentials were sensitive to γ- aminobutyric acid-A (GABA(A)) or α-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid (AMPA) antagonists in presumed somatic and dendritic impalements, respectively. Pharmacological blockage of spontaneous synaptic events produced large increases in input resistance that were more important in dendritic (≃50%) than somatic (≃10%) impalements. These findings imply that hi the intact brain, pyramidal neurons are submitted to an intense spike-independent synaptic bombardment that decreases the space constant of the cells. These results should be taken into account when extrapolating in vitro findings to intact brains.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1735-1739 |
| Number of pages | 5 |
| Journal | Journal of neurophysiology |
| Volume | 78 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jan 1 1997 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Neuroscience(all)
- Physiology
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Differential impact of miniature synaptic potentials on the soma and dendrites of pyramidal neurons in vivo. / Pare, Denis; Lebel, Elen; Lang, Eric J.
In: Journal of neurophysiology, Vol. 78, No. 3, 01.01.1997, p. 1735-1739.Research output: Contribution to journal › Article
TY - JOUR
T1 - Differential impact of miniature synaptic potentials on the soma and dendrites of pyramidal neurons in vivo
AU - Pare, Denis
AU - Lebel, Elen
AU - Lang, Eric J.
PY - 1997/1/1
Y1 - 1997/1/1
N2 - We studied the impact of transmitter release resistant to tetrodotoxin (TTX) in morphologically identified neocortical pyramidal neurons recorded intracellularly in barbiturate-anesthetized cats. It was observed that TTX- resistant release occurs in pyramidal neurons in vivo and at much higher frequencies than was previously reported in vitro. Further, in agreement with previous findings indicating that GABAergic and glutamatergic synapses are differentially distributed in the somata and dendrites of pyramidal cells, we found that most miniature synaptic potentials were sensitive to γ- aminobutyric acid-A (GABA(A)) or α-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid (AMPA) antagonists in presumed somatic and dendritic impalements, respectively. Pharmacological blockage of spontaneous synaptic events produced large increases in input resistance that were more important in dendritic (≃50%) than somatic (≃10%) impalements. These findings imply that hi the intact brain, pyramidal neurons are submitted to an intense spike-independent synaptic bombardment that decreases the space constant of the cells. These results should be taken into account when extrapolating in vitro findings to intact brains.
AB - We studied the impact of transmitter release resistant to tetrodotoxin (TTX) in morphologically identified neocortical pyramidal neurons recorded intracellularly in barbiturate-anesthetized cats. It was observed that TTX- resistant release occurs in pyramidal neurons in vivo and at much higher frequencies than was previously reported in vitro. Further, in agreement with previous findings indicating that GABAergic and glutamatergic synapses are differentially distributed in the somata and dendrites of pyramidal cells, we found that most miniature synaptic potentials were sensitive to γ- aminobutyric acid-A (GABA(A)) or α-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid (AMPA) antagonists in presumed somatic and dendritic impalements, respectively. Pharmacological blockage of spontaneous synaptic events produced large increases in input resistance that were more important in dendritic (≃50%) than somatic (≃10%) impalements. These findings imply that hi the intact brain, pyramidal neurons are submitted to an intense spike-independent synaptic bombardment that decreases the space constant of the cells. These results should be taken into account when extrapolating in vitro findings to intact brains.
UR - http://www.scopus.com/inward/record.url?scp=0030865856&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030865856&partnerID=8YFLogxK
U2 - 10.1152/jn.1997.78.3.1735
DO - 10.1152/jn.1997.78.3.1735
M3 - Article
VL - 78
SP - 1735
EP - 1739
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
SN - 0022-3077
IS - 3
ER -