Spatiotemporal asymmetry of associative synaptic plasticity in fear conditioning pathways.
Input-specific long-term potentiation (LTP) in afferent inputs to the amygdala serves an essential function in the acquisition of fear memory. Factors underlying input specificity of synaptic modifications implicated in information transfer in fear conditioning pathways remain unclear. Here we show that the strength of naive synapses in two auditory inputs converging on a single neuron in the lateral nucleus of the amygdala (LA) is only modified when a postsynaptic action potential closely follows a synaptic response. The stronger inhibitory drive in thalamic pathway, as compared with cortical input, hampers the induction of LTP at thalamo-amygdala synapses, contributing to the spatial specificity of LTP in convergent inputs. These results indicate that spike timing-dependent synaptic plasticity in afferent projections to the LA is both temporarily and spatially asymmetric, thus providing a mechanism for the conditioned stimulus discrimination during fear behavior.
Shin
Ryong-Moon
RM
Department of Psychiatry, McLean Hospital, Harvard Medical School, 115 Mill Street, Belmont, Massachusetts 02478, USA.
Tsvetkov
Evgeny
E
Bolshakov
Vadim Y
VY
D000200:Action Potentials / Q000502:physiology; D000679:Amygdala / Q000502:physiology; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology; D003213:Conditioning, Psychological / Q000502:physiology*; D004594:Electrophysiology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005239:Fear / Q000502:physiology*; D005971:Glutamates / Q000502:physiology; D066298:In Vitro Techniques; D007395:Interneurons / Q000502:physiology; D017774:Long-Term Potentiation / Q000502:physiology; D008568:Memory / Q000502:physiology*; D009434:Neural Pathways / Q000166:cytology / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009475:Neurons, Afferent / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology; D013788:Thalamus / Q000502:physiology
D005971:Glutamates; D016194:Receptors, N-Methyl-D-Aspartate