Psychostimulant-induced plasticity of intrinsic neuronal excitability in ventral subiculum.
Psychostimulant drugs such as amphetamine are prescribed to increase vigilance, suppress appetite, and treat attention disorders, but they powerfully activate the dopamine system and have serious abuse potential. Repeated psychostimulant exposure induces neuronal plasticity within the mesolimbic dopamine system. Here we present evidence that repeated amphetamine exposure results in a suppression of intrinsic neuronal excitability in the ventral subiculum, a hippocampal region that activates dopamine neurotransmission. We used patch-clamp recordings from brain slices obtained at different times after withdrawal from repeated amphetamine exposure to determine the long-term effects of amphetamine on subicular excitability. Using several postsynaptic indices of sodium channel function, our results show that excitability is decreased for days, but not weeks, after repeated amphetamine exposure. The resulting increase in action potential threshold and decrease in postsynaptic amplification of excitatory synaptic input provide the first direct evidence that psychostimulants induce plasticity of hippocampal output and suggest one mechanism by which drug withdrawal may influence limbic dopamine-dependent learning and memory.
Cooper
Donald C
DC
Department of Neurobiology and Physiology, Institute for Neuroscience, Northwestern University, Evanston, Illinois 60208, USA.
Moore
Shannon J
SJ
Staff
Nathan P
NP
Spruston
Nelson
N
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D001683:Biological Clocks / Q000187:drug effects; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects* / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012684:Sensory Thresholds / Q000187:drug effects; D013569:Synapses / Q000502:physiology
D000697:Central Nervous System Stimulants; D000661:Amphetamine