Dendritic spine heterogeneity determines afferent-specific Hebbian plasticity in the amygdala

Neuron. 2005 Jan 6;45(1):119-31. doi: 10.1016/j.neuron.2004.12.019.

Abstract

Functional compartmentalization of dendrites is thought to underlie afferent-specific integration of neural activity in laminar brain structures. Here we show that in the lateral nucleus of the amygdala (LA), an area lacking apparent laminar organization, thalamic and cortical afferents converge on the same dendrites, contacting neighboring but morphologically and functionally distinct spine types. Large spines contacted by thalamic afferents exhibited larger Ca(2+) transients during action potential backpropagation than did small spines contacted by cortical afferents. Accordingly, induction of Hebbian plasticity, dependent on postsynaptic spikes, was restricted to thalamic afferents. This synapse-specific effect involved activation of R-type voltage-dependent Ca(2+) channels preferentially located at thalamic inputs. These results indicate that afferent-specific mechanisms of postsynaptic, associative Hebbian plasticity in LA projection neurons depend on local, spine-specific morphological and molecular properties, rather than global differences between dendritic compartments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Action Potentials / physiology
  • Afferent Pathways / physiology*
  • Afferent Pathways / ultrastructure
  • Amygdala / cytology
  • Amygdala / physiology*
  • Animals
  • Calcium Channel Blockers / pharmacology
  • Calcium Channels / drug effects
  • Calcium Channels / physiology
  • Calcium Signaling / drug effects
  • Calcium Signaling / physiology*
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology
  • Dendritic Spines / physiology*
  • Dendritic Spines / ultrastructure
  • Excitatory Amino Acid Antagonists / pharmacology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Nerve Tissue Proteins / metabolism
  • Neuronal Plasticity / drug effects
  • Neuronal Plasticity / physiology*
  • Organ Culture Techniques
  • Patch-Clamp Techniques
  • Phytohemagglutinins
  • Presynaptic Terminals / physiology
  • Presynaptic Terminals / ultrastructure
  • Synaptic Membranes / metabolism
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology*
  • Thalamus / cytology
  • Thalamus / physiology

Substances

  • Calcium Channel Blockers
  • Calcium Channels
  • Excitatory Amino Acid Antagonists
  • Nerve Tissue Proteins
  • Phytohemagglutinins
  • leukoagglutinins, plants
  • postsynaptic density proteins