|
|
||||||||
The Journal of Neurophysiology Vol. 82 No. 1 July 1999, pp. 69-85
Copyright ©1999 by the American Physiological Society
Harvard Medical School and Brockton Veterans Affairs Medical Center, Department of Psychiatry, Neuroscience Laboratory 151C, Brockton, Massachusetts 02301
Rainnie, Donald G.
Serotonergic Modulation of Neurotransmission in the Rat
Basolateral Amygdala. J. Neurophysiol. 82: 69-85, 1999.
Whole cell patch-clamp recordings were obtained
from projection neurons and interneurons of the rat basolateral
amygdala (BLA) to understand local network interactions in
morphologically identified neurons and their modulation by serotonin.
Projection neurons and interneurons were characterized morphologically
and electrophysiologically according to their intrinsic membrane
properties and synaptic characteristics. Synaptic activity in
projection neurons was dominated by spontaneous inhibitory postsynaptic
currents (IPSCs) that were multiphasic, reached 181 ± 38 pA in
amplitude, lasted 296 ± 27 mS, and were blocked by the
GABAA receptor antagonist, bicuculline methiodide (30 µM). In interneurons, spontaneous synaptic activity was characterized
by a burst-firing discharge patterns (200 ± 40 Hz) that
correlated with the occurrence of
6-cyano-7-nitroquinoxaline-2,3-dione-sensitive, high-amplitude
(260 ± 42 pA), long-duration (139 ± 19 mS) inward excitatory postsynaptic currents (EPSCs). The interevent interval of
831 ± 344 mS for compound inhibitory postsynaptic potentials (IPSPs), and 916 ± 270 mS for EPSC bursts, suggested that
spontaneous IPSP/Cs in projection neurons are driven by burst of action
potentials in interneurons. Hence, BLA interneurons may regulate the
excitability of projection neurons and thus determine the degree of
synchrony within ensembles of BLA neurons. In interneurons
5-hydroxytryptamine oxalate (5-HT) evoked a direct, dose-dependent,
membrane depolarization mediated by a 45 ± 6.9 pA inward current,
which had a reversal potential of
90 mV. The effect of 5-HT was
mimicked by the 5-HT2 receptor agonist,
-methyl-5-hydroxytryptamine (
-methyl-5-HT), but not by the
5-HT1A receptor agonist, (±)
8-hydroxydipropylaminotetralin hydrobromide (8-OH-DPAT), or the
5-HT1B agonist, CGS 12066A. In projection neurons, 5-HT
evoked an indirect membrane hyperpolarization (~2 mV) that was
associated with a 75 ± 42 pA outward current and had a reversal
potential of
70 mV. The response was independent of 5-HT
concentration, blocked by TTX, mimicked by
-methyl-5-HT but not by
8-OH-DPAT. In interneurons, 5-HT reduced the amplitude of the evoked
EPSC and in the presence of TTX (0.6 µM) reduced the frequency of
miniature EPSCs but not their quantal content. In projection neurons,
5-HT also caused a dose-dependent reduction in the amplitude of
stimulus evoked EPSCs and IPSCs. These results suggest that acute
serotonin release would directly activate GABAergic interneurons of the
BLA, via an activation of 5-HT2 receptors, and increase the
frequency of inhibitory synaptic events in projection neurons. Chronic
serotonin release, or high levels of serotonin, would reduce the
excitatory drive onto interneurons and may act as a feedback mechanism
to prevent excess inhibition within the nucleus.
This article has been cited by other articles:
![]() |
L. Chung and S. D. Moore Cholecystokinin Excites Interneurons in Rat Basolateral Amygdala J Neurophysiol, July 1, 2009; 102(1): 272 - 284. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Jasnow, K. J. Ressler, S. E. Hammack, J. P. Chhatwal, and D. G. Rainnie Distinct Subtypes of Cholecystokinin (CCK)-Containing Interneurons of the Basolateral Amygdala Identified Using a CCK Promoter-Specific Lentivirus J Neurophysiol, March 1, 2009; 101(3): 1494 - 1506. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. Ruden Encoding States: A Model for the Origin and Treatment of Complex Psychogenic Pain Traumatology, March 1, 2008; 14(1): 119 - 126. [Abstract] [PDF] |
||||
![]() |
A. K. Lack, M. R. Diaz, A. Chappell, D. W. DuBois, and B. A. McCool Chronic Ethanol and Withdrawal Differentially Modulate Pre- and Postsynaptic Function at Glutamatergic Synapses in Rat Basolateral Amygdala J Neurophysiol, December 1, 2007; 98(6): 3185 - 3196. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y.-Y. Huang and E. R. Kandel 5-Hydroxytryptamine Induces a Protein Kinase A/Mitogen-Activated Protein Kinase-Mediated and Macromolecular Synthesis-Dependent Late Phase of Long-Term Potentiation in the Amygdala J. Neurosci., March 21, 2007; 27(12): 3111 - 3119. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. G. Rainnie, R. Bergeron, T. J. Sajdyk, M. Patil, D. R. Gehlert, and A. Shekhar Corticotrophin Releasing Factor-Induced Synaptic Plasticity in the Amygdala Translates Stress into Emotional Disorders J. Neurosci., April 7, 2004; 24(14): 3471 - 3479. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Schneider, E. Wilkins, A. Firestone, E. C. Everbach, J. C. Naylor, and P. E. Simson Enhanced Retention in the Passive-Avoidance Task By 5-HT1A Receptor Blockade Is Not Associated With Increased Activity of the Central Nucleus of the Amygdala Learn. Mem., September 1, 2003; 10(5): 394 - 400. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Kann, R. Kovacs, and U. Heinemann Metabotropic Receptor-Mediated Ca2+ Signaling Elevates Mitochondrial Ca2+ and Stimulates Oxidative Metabolism in Hippocampal Slice Cultures J Neurophysiol, August 1, 2003; 90(2): 613 - 621. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. R. Hariri, V. S. Mattay, A. Tessitore, B. Kolachana, F. Fera, D. Goldman, M. F. Egan, and D. R. Weinberger Serotonin Transporter Genetic Variation and the Response of the Human Amygdala Science, July 19, 2002; 297(5580): 400 - 403. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Tor-Agbidye, B. Yamamoto, and J. F. Bowyer Seizure Activity and Hyperthermia Potentiate the Increases in Dopamine and Serotonin Extracellular Levels in the Amygdala during Exposure to d-Amphetamine Toxicol. Sci., March 1, 2001; 60(1): 103 - 111. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Sibille, C. Pavlides, D. Benke, and M. Toth Genetic Inactivation of the Serotonin1A Receptor in Mice Results in Downregulation of Major GABAA Receptor alpha Subunits, Reduction of GABAA Receptor Binding, and Benzodiazepine-Resistant Anxiety J. Neurosci., April 15, 2000; 20(8): 2758 - 2765. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |