D1R agonist or antagonist in LHb impaired the acquisition of contextual fear memory in rats. D1R agonist or antagonist in LHb impaired long term potentiation (LTP) in hippocampal CA3-CA1 synapses. D1R agonist or antagonist in LHb attenuated learning induced phosphorylation of AMPAR subunit 1 (GluA1) at Ser831 and Ser845 in hippocampus. Dysfunction of D1R in LHb affected the function of hippocampus.