The Function Of The Sigma-1 Receptor On Hippocampal Synaptic Plasticity Underlying Addiction Retrieval

Sigma-1 receptor as a regulator of dopamine neurotransmission,plays a vital role in addiction mechanism.Meanwhile,it is widely expressed in the central neural system(CNS),especially in hippocampus,substantia nigra,striatum and the like.Sigma-1 receptor is a chaperone protein at the membrane which connecting the endoplasmic reticulum(ER)and mitochondria.Lots of studies indicated that sigma-1 receptor may contribute to many CNS related diseases,such as dysmnesia,pain,depression,Alzheimer's disease,schizophrenia.Recently,researches found that sigma-1 receptor may enhance the neurosynaptic plasticity underlying the addiction.But the mechanism is barely understood.As synaptic plasticity is known as the fundamental mechanism of learning and memory.And addiction can be regarded as a kind of special memory(unforgettable memory).So that the sigma-1 receptor may affect the addictive memory by altering the hippocampal synaptic plasticity.In this investigation,we found that the hippocampal long-term potentiation(LTP)of mice,who retrieval the morphine conditioned place preference(MCPP),was impaired.And activating sigma-1 receptor could enhance the LTP of hippocampal CA1 sub-region in mice.But activating Sigma-1 receptor before MCPP retrieval couldn't affect the MCPP expression.In addition,methylamphetamine could induce the CPP expression in mice without changing the hippocampal CA1 synaptic plasticity.