Dopamine Regulates Aversive Contextual Learning and Associated In Vivo Synaptic Plasticity in the Hippocampus.
Dopamine release during reward-driven behaviors influences synaptic plasticity. However, dopamine innervation and release in the hippocampus and its role during aversive behaviors are controversial. Here, we show that in vivo hippocampal synaptic plasticity in the CA3-CA1 circuit underlies contextual learning during inhibitory avoidance (IA) training. Immunohistochemistry and molecular techniques verified sparse dopaminergic innervation of the hippocampus from the midbrain. The long-term synaptic potentiation (LTP) underlying the learning of IA was assessed with a D1-like dopamine receptor agonist or antagonist in ex vivo hippocampal slices and in vivo in freely moving mice. Inhibition of D1-like dopamine receptors impaired memory of the IA task and prevented the training-induced enhancement of both ex vivo and in vivo LTP induction. The results indicate that dopamine-receptor signaling during an aversive contextual task regulates aversive memory retention and regulates associated synaptic mechanisms in the hippocampus that likely underlie learning.
['Broussard|John I|JI|', 'Yang|Kechun|K|', 'Levine|Amber T|AT|', 'Tsetsenis|Theodoros|T|', 'Jenson|Daniel|D|', 'Cao|Fei|F|', 'Garcia|Isabella|I|', 'Arenkiel|Benjamin R|BR|', 'Zhou|Fu-Ming|FM|', 'De Biasi|Mariella|M|', 'Dani|John A|JA|']
D000200:Action Potentials D000818:Animals D001362:Avoidance Learning D001552:Benzazepines D056547:CA1 Region, Hippocampal D056654:CA3 Region, Hippocampal D003213:Conditioning, Psychological D004298:Dopamine D004566:Electrodes D007858:Learning D017774:Long-Term Potentiation D057567:Memory, Long-Term D008636:Mesencephalon D051379:Mice D008810:Mice, Inbred C57BL D008867:Microtomy D017966:Pyramidal Cells D017447:Receptors, Dopamine D1 D013569:Synapses D009435:Synaptic Transmission D046509:Tissue Culture Techniques
inhibitory avoidance LTP memory fear conditioning in vivo recording passive avoidance ventral tegmental area