Convergent but temporally separated inputs to lateral amygdala neurons from the auditory thalamus and auditory cortex use different postsynaptic receptors: In vivo intracellular and extracellular recordings in fear conditioning pathways

Author(s): Stutzmann, G. E., Ledoux, J. E.

Journal/Book: Learn Memory. 1996; 3: 1 Bungtown Rd, Plainview, NY 11724. Cold Spring Harbor Lab Press. 229-242.

Abstract: The lateral nucleus of the amygdala (LA), a key component of the fear conditioning circuitry, receives a rapid but relatively impoverished auditory input from the auditory thalamus and a slower but richer input from the auditory cortex. We examined in urethane anesthetized rats whether individual cells in the LA receive convergent inputs from these two areas, and whether different postsynaptic receptors contribute to the temporally separated excitations over the two pathways. With both extracellular and intracellular recordings, individual cells could be activated by stimulation of each pathway. in extracellular recordings iontophoretic application of the N-methyl-D-aspartate (NMDA) receptor antagonist APV and the: L-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor antagonist CNQX demonstrated that synaptic transmission in both pathways depends on AMPA receptors, whereas transmission in the thalamic pathway also depends on the involvement of NMDA receptors. The involvement of NMDA receptors in synaptic activation of the LA from the thalamus but not the cortex was confirmed in intracellular recordings.

Note: Article JE Ledoux, NYU, Ctr Neural Sci, New York, NY 10003 USA

Keyword(s): MAGNESIUM-FREE SOLUTION; LONG-TERM POTENTIATION; MEDIAL GENICULATE-BODY; NON-NMDA RECEPTORS; BASOLATERAL AMYGDALA; RESPONSE PROPERTIES; RAT AMYGDALA; SYNAPTIC POTENTIATION; HIPPOCAMPAL-FORMATION; DISCHARGE PATTERNS

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