Essential role of D1 but not D2 receptors in methamphetamine-induced impairment of long-term potentiation in hippocampal-prefrontal cortex pathway.

Methamphetamine (MA) abuse induces deficits in cognitive performance that are related to dysfunction of the prefrontal cortex (PFC). The medial portion of the prefrontal cortex (mPFC) in rats that is crucial for cognitive function has been shown to undergo long-term potentiation (LTP) in the projections from the hippocampus. However, no study has been performed to evaluate the influence of MA on synaptic plasticity in the hippocampal-mPFC pathways.

Neurotoxic morphological changes induced in the medial prefrontal cortex of rats behaviorally sensitized to methamphetamine.

The present study examined whether the development in rats of behavioral sensitization to methamphetamine (MAP) is related to the development of neurotoxic morphological changes presumably induced in the medial prefrontal cortex (MFC). Male rats were intraperitonieally injected with MAP (5 mg/kg) once a day for 12 days (day 1-day 12), and then the drug was withdrawn for 7-42 days (WD7-WD42). The MAP- treatment caused hypersensitivity of a successive head-movement stereotypy, which reached a basic plateau level on day 4, and rose successively to a higher level by day 12.

Rapid structural remodeling of shaft synapses associated with long-term potentiation in the cat superior cervical ganglion in situ.

Synaptic plasticity associated with long-term potentiation was studied electrophysiologically and ultrastructurally in the cat superior cervical ganglion in situ. The preganglionic nerve fiber was stimulated at 10 Hz for 50 s for conditioning and then at 1 Hz for 1-3 h to monitor changes in the postganglionic compound action potential (PGP). The present material has shown the long-term potentiation (LTP), around 120% of the control, which lasted for up to 3 h.