Prelimbic cortex dynorphin/κ opioid receptor system modulates methamphetamine-induced cognitive impairment.

Chronic exposure to methamphetamine (METH) causes severe and persistent cognitive impairment. The present study aimed to investigate the role of dynorphin/κ opioid receptor (KOR) system in the development of METH-induced cognitive impairment. We found that mice showed significant cognitive impairment in the novel object recognition test (NOR) following daily injections of METH (10 mg/kg) for seven consecutive days. Systemic blockade of KOR prevented METH-induced cognitive impairment by pretreatment of the selective KOR antagonist norBNI (10 mg/kg, i.p.) or KOR deletion. Then, significant increased dynorphin and KOR mRNA were observed exclusively in prelimbic cortex (PL) other than infralimbic cortex. Finally, microinjection with norBNI into PL also improved cognitive memory in METH-treated mice using NOR and spontaneous alternation behaviour test. Our results demonstrated that dynorphin/KOR system activation in PL may be a possible mechanism for METH-induced cognitive impairment and shed light on KOR antagonists as a potential neuroprotective agent against the cognitive deficits induced by drug abuse.

[Comprehensive characterization of main components and microstructures in five different species of Salvia miltiorrhiza bge].

Studied with X-ray fluorescence spectrum analytic (XRF), powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR) for five different species of Salvia miltiorrhiza bge grew in Anguo, the intrinsic components and microstructures were determined and comprehensive characterization was carried out. The figure of comprehensive characterization can describe characteristics of intrinsic components from elements, crystal and amorphous active component, it can give an intuitive description for the same components and subtle differences in the intrinsic components of Salvia miltiorrhiza bge, which are different idioplasmatic and same species. It is the ideal method because of the simple preparation of sample, rapid and fine accurate measurement with reproducibility and objectivity, so that it can be used for breeding of fine varieties of Chinese medicinal materials, Chinese medicinal materials GAP guidance of growing conditions, medicinal origin characteristics, the intrinsic composition and microstructure characterization, quality control and authenticity of the identification.