No abstract

No abstract

No abstract

Seizure-like burst activities are induced by blockade of GABA A and/or glycine receptors in various spinal ventral roots of brainstem-spinal cord preparation from neonatal rodents. We found that this is not applicable to the phrenic nerve and that a new inhibitory descending pathway may suppress seizure-like activity in the phrenic nerve. Experiments were performed in brainstem-spinal cord preparation from newborn rats (age: 0-1 day). Left phrenic nerve and right C4 activities were recorded simultaneously. When GABA A and glycine receptors were blocked by 10 μM bicuculline and 10 μM strychnine (Bic+Str), seizure-like burst activities appeared in the fourth cervical ventral root (C4) but not the phrenic nerve. After making a transverse section at C1, the inspiratory burst activity disappeared from both C4 and the phrenic nerve, whereas seizure-like activity appeared in both nerves. We hypothesized that inhibitory descending pathways other than those via GABA A and/or glycine receptors (from the medulla to the spinal cord) work to avoid disturbance of regular respiratory-related diaphragm contraction by seizure-like activity. We found that cannabinoid receptor antagonist, AM251 was effective for the induction of seizure-like activity by Bic+Str in the phrenic nerve in brainstem-spinal cord preparation. Cannabinoid receptors may be involved in this descending inhibitory system.

Layer-by-layer (LbL) deposition of poly(L-lysine) (PLL) dissolved in different solutions and a water-soluble titania precursor, titanium(IV) bis(ammonium lactate) dihydroxide (TiBALDH) to form multilayer films on the wall of polycarbonate (PC) membrane pores was performed to prepare nanostructured titania-PLL composite and pure anatase and rutile titania tubes. A battery of analytical techniques was utilized to characterize and compare the structures, crystal phases, and photocatalytic properties of the titania tubes. In different solutions conditions, PLL which adopts secondary conformations (i.e., alpha-helix and random coil) and has varying interactions with different counterions (i.e., chloride and phosphate ions) can influence PLL/TiBALDH deposition and, in turn, results in the titania materials with different nanostructures and phtocatalytic properties. The influence of LbL assembly condition, deposition cycle, and polypeptide molecular weight on photocatalytic properties of resultant anatase titania tubes were further explored and these materials are promising photocatalyst with the advantage of easily handling and recycling. This reported approach may provide a facile and general way to prepare organic-inorganic composite and other inorganic materials with different compositions, structures, and properties for various applications.