title: Asymmetrical synaptic cooperation between cortical and thalamic inputs to the amygdale.
abstract: Fear conditioning, a form of associative learning is thought to involve the induction of an associative long-term potentiation of cortical and thalamic inputs to the lateral amygdala. Here, we show that stimulation of the thalamic input can reinforce a transient form of plasticity (E-LTP) induced by weak stimulation of the cortical inputs. This synaptic cooperation occurs within a time window of 30 min, suggesting that synaptic integration at amygdala synapses can occur within large time windows. Interestingly, we found that synaptic cooperation is not symmetrical. Reinforcement of a thalamic E-LTP by subsequent cortical stimulation is only observed within a shorter time window. We found that activation of endocannabinoid CB1 receptors is involved in the time restriction of thalamic and cortical synaptic cooperation in an activity-dependent manner. Our results support the hypothesis that synaptic cooperation can underlie associative learning and that synaptic tagging and capture is a general mechanism in synaptic plasticity.
authors.affiliation: Champalimaud Neuroscience Program at Gulbenkian Institute of Science, Oeiras, Portugal.
authors.forename: Rosalina
authors.initials: R
authors.lastname: Fonseca
mesh_terms: D000679:Amygdala / Q000502:physiology*; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D063386:Cannabinoid Receptor Agonists / Q000494:pharmacology; D063387:Cannabinoid Receptor Antagonists / Q000494:pharmacology; D002540:Cerebral Cortex / Q000166:cytology* / Q000502:physiology; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology*; D007166:Immunosuppressive Agents / Q000494:pharmacology; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D020123:Sirolimus / Q000494:pharmacology; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D013788:Thalamus / Q000166:cytology* / Q000502:physiology; D013997:Time Factors
chemical_list: D002121:Calcium Channel Blockers; D063386:Cannabinoid Receptor Agonists; D063387:Cannabinoid Receptor Antagonists; D018691:Excitatory Amino Acid Antagonists; D007166:Immunosuppressive Agents; D020123:Sirolimus