| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Département de Physiologie, Université Laval, Québec, Québec G1K 7P4, Canada
Lang, E. J. and D. Paré. Similar inhibitory processes dominate the responses of cat lateral amygdaloid projection neurons to their various afferents. J. Neurophysiol. 77: 341-352, 1997. To investigate the impact of inhibitory processes on responses of lateral amygdaloid (LAT) neurons, intracellular recordings were obtained from identified LAT projection neurons in barbiturate-anesthetized cats. Synaptic responses evoked by perirhinal (PRH), entorhinal (ENT), basomedial, and LAT stimulation were investigated. Regardless of stimulation site, responses consisted of an excitatory postsynaptic potential (EPSP) that either preceded and was truncated by an inhibitory postsynaptic potential (IPSP) or occurred just after the IPSP onset. IPSPs were monophasic, lasted hundreds of milliseconds, and were of such large amplitude and rapid onset that they effectively opposed the EPSPs, generally preventing orthodromic spikes. All sites elicited IPSPs with relatively negative reversal potentials around 
85 mV. Experiments analyzing the underlying ionic mechanisms are presented in the companion paper. Evoked responses were similar to synaptic potentials associated with spontaneous EEG events, known as simple (small, monophasic) and complex (large, triphasic) ENT sharp potentials (SPs), with no difference between the reversals of evoked and SP-related IPSPs (83.2 ± 2.7 mV). IPSPs coinciding with complex SPs truncated SP-related EPSPs more rapidly and had larger amplitudes and longer durations than those related to simple SPs. These differences reflected the fact that the amplitude and duration of SP-related IPSPs were correlated with SP amplitude. Similar variations were reproduced in evoked IPSPs by varying the stimulus intensity. Low intensities generated predominantly excitatory responses consisting of EPSPs sometimes followed by small IPSPs, whereas high intensities evoked predominantly inhibitory responses comprised of a large IPSP that truncated or occluded the EPSPs. Orthodromic spikes were elicited only in a narrow range of intermediate intensities. These changes in the evoked response primarily reflected increases in the IPSP evoked at high intensities. PRH stimulation at different rostro-caudal levels demonstrated that rostral sites elicited larger EPSPs and IPSPs with shorter latencies and longer durations than caudal sites. These differences probably reflect contrasting patterns of activity spread through the PRH cortex, suggesting that the intact cortical circuitry allowed a temporally distributed activation of inhibitory interneurons and thereby partly explains the long duration and monophasic nature of the IPSPs. Inhibition, thus, plays a primary role in shaping LAT neuronal responses. The profuse intrinsic connectivity of the LAT nucleus and parahippocampal cortices may underlie the relatively invariant response pattern of LAT neurons and suggests a common mode of information processing, based upon quantitative, rather than qualitative, differences in activation of LAT circuitry. Therefore we propose that effective transmission of signals through the LAT nucleus may require activation of specifically sized neuronal ensembles, rather than widespread afferent excitation.
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]
|
|
|
|
|
|
G. Li, S. S. Nair, and G. J. Quirk A Biologically Realistic Network Model of Acquisition and Extinction of Conditioned Fear Associations in Lateral Amygdala Neurons J Neurophysiol, March 1, 2009; 101(3): 1629 - 1646. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Du, Q. Huang, X. Wu, G. C. Galbraith, and L. Li Binaural Unmasking of Frequency-Following Responses in Rat Amygdala J Neurophysiol, March 1, 2009; 101(3): 1647 - 1659. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Esmaeili, J. W. Lynch, and P. Sah GABAA Receptors Containing Gamma1 Subunits Contribute to Inhibitory Transmission in the Central Amygdala J Neurophysiol, January 1, 2009; 101(1): 341 - 349. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. S. L. Faber, A. J. Delaney, J. M. Power, P. L. Sedlak, J. W. Crane, and P. Sah Modulation of SK Channel Trafficking by Beta Adrenoceptors Enhances Excitatory Synaptic Transmission and Plasticity in the Amygdala J. Neurosci., October 22, 2008; 28(43): 10803 - 10813. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Bergado-Acosta, S. Sangha, R. T. Narayanan, K. Obata, H.-C. Pape, and O. Stork Critical role of the 65-kDa isoform of glutamic acid decarboxylase in consolidation and generalization of Pavlovian fear memory Learn. Mem., March 5, 2008; 15(3): 163 - 171. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B.-X. Pan, F. Vautier, W. Ito, V. Y. Bolshakov, and A. Morozov Enhanced Cortico-Amygdala Efficacy and Suppressed Fear in Absence of Rap1 J. Neurosci., February 27, 2008; 28(9): 2089 - 2098. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. R. Woodruff and P. Sah Inhibition and Synchronization of Basal Amygdala Principal Neuron Spiking by Parvalbumin-Positive Interneurons J Neurophysiol, November 1, 2007; 98(5): 2956 - 2961. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Herry, D. R. Bach, F. Esposito, F. Di Salle, W. J. Perrig, K. Scheffler, A. Luthi, and E. Seifritz Processing of Temporal Unpredictability in Human and Animal Amygdala J. Neurosci., May 30, 2007; 27(22): 5958 - 5966. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Likhtik, J. G. Pelletier, A. T. Popescu, and D. Pare Identification of Basolateral Amygdala Projection Cells and Interneurons Using Extracellular Recordings J Neurophysiol, December 1, 2006; 96(6): 3257 - 3265. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Benini and M. Avoli Altered Inhibition in Lateral Amygdala Networks in a Rat Model of Temporal Lobe Epilepsy J Neurophysiol, April 1, 2006; 95(4): 2143 - 2154. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Higley and D. Contreras Integration of Synaptic Responses to Neighboring Whiskers in Rat Barrel Cortex In Vivo J Neurophysiol, April 1, 2005; 93(4): 1920 - 1934. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. P. Bauer and J. E. LeDoux Heterosynaptic Long-Term Potentiation of Inhibitory Interneurons in the Lateral Amygdala J. Neurosci., October 27, 2004; 24(43): 9507 - 9512. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Lopez De Armentia and P. Sah Firing Properties and Connectivity of Neurons in the Rat Lateral Central Nucleus of the Amygdala J Neurophysiol, September 1, 2004; 92(3): 1285 - 1294. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. SAH, E. S. L. FABER, M. LOPEZ DE ARMENTIA, and J. POWER The Amygdaloid Complex: Anatomy and Physiology Physiol Rev, July 1, 2003; 83(3): 803 - 834. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Szinyei, O. Stork, and H.-C. Pape Contribution of NR2B Subunits to Synaptic Transmission in Amygdaloid Interneurons J. Neurosci., April 1, 2003; 23(7): 2549 - 2556. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. D. Samson, E. C. Dumont, and D. Pare Feedback Inhibition Defines Transverse Processing Modules in the Lateral Amygdala J. Neurosci., March 1, 2003; 23(5): 1966 - 1973. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. G. Pelletier and D. Pare Uniform Range of Conduction Times From the Lateral Amygdala to Distributed Perirhinal Sites J Neurophysiol, March 1, 2002; 87(3): 1213 - 1221. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Rosenkranz and A. A. Grace Cellular Mechanisms of Infralimbic and Prelimbic Prefrontal Cortical Inhibition and Dopaminergic Modulation of Basolateral Amygdala Neurons In Vivo J. Neurosci., January 1, 2002; 22(1): 324 - 337. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Meis and H.-C. Pape Control of glutamate and GABA release by nociceptin/orphanin FQ in the rat lateral amygdala J. Physiol., May 1, 2001; 532(3): 701 - 712. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Szinyei, T. Heinbockel, J. Montagne, and H.-C. Pape Putative Cortical and Thalamic Inputs Elicit Convergent Excitation in a Population of GABAergic Interneurons of the Lateral Amygdala J. Neurosci., December 1, 2000; 20(23): 8909 - 8915. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Pare and D. R. Collins Neuronal Correlates of Fear in the Lateral Amygdala: Multiple Extracellular Recordings in Conscious Cats J. Neurosci., April 1, 2000; 20(7): 2701 - 2710. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Rosenkranz and A. A. Grace Modulation of Basolateral Amygdala Neuronal Firing and Afferent Drive by Dopamine Receptor Activation In Vivo J. Neurosci., December 15, 1999; 19(24): 11027 - 11039. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. G. Rainnie Serotonergic Modulation of Neurotransmission in the Rat Basolateral Amygdala J Neurophysiol, July 1, 1999; 82(1): 69 - 85. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. J. Lang and D. Pare Synaptic and Synaptically Activated Intrinsic Conductances Underlie Inhibitory Potentials in Cat Lateral Amygdaloid Projection Neurons In Vivo J Neurophysiol, January 1, 1997; 77(1): 353 - 363. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
