ABSTRACT
Ultrastructural parameters related to synaptic release and their correlation with synaptic connectivity were analyzed in the low-threshold mechanoreceptive vibrissa afferent boutons in laminae III and IV of the trigeminal caudal nucleus (Vc). Rapidly adapting vibrissa afferents were intra-axonally labeled, and quantitative ultrastructural analyses with serial sections were performed on the labeled boutons and their presynaptic endings (p-endings). The volume of the labeled boutons was widely distributed from small to large ones (0.8~12.3 microm3), whereas the p-endings were small and uniform in size. The volume of the labeled boutons was positively correlated with the ultrastructural parameters such as mitochondrial volume (correlation coefficient, r=0.96), active zone area (r=0.82) and apposed surface area (r=0.79). Vesicle density (r=-0.18) showed little correlation to the volume of labeled boutons, suggesting that the total vesicle number of a bouton is proportional to its volume. In addition, the bouton volume was positively correlated with the number of p-endings (r=0.52) and with the number of dendrites postsynaptic to the labeled bouton (r=0.83). These findings suggest that low-threshold mechanoreception conveyed through vibrissa afferents is processed in a bouton size-dependent manner in the Vc, which may contribute to the sensory-motor function of laminae III/IV in Vc.
Subject(s)
Animals , Cats , Dendrites , Mitochondrial Size , Synapses , Trigeminal Caudal NucleusABSTRACT
PURPOSE: Because vascular access sites in neonates are limited, intravenous (IV) medications must often be mixed with maintenance fluids, including parenteral nutrient (PN) solutions. This study was done to determine whether IV medications commonly prescribed in the neonatal in- tensive care unit (NICU) are compatible with the two neonatal PN solutions. METHODS: The compatibility of neonatal PN solutions and selected other drugs during Y-site delivery was evaluated. Secondary drugs were administered at selected concentrations, rates and delivery by method commonly used at the NICU. Drugs administered by syringe pump over 30min : amikacin, cefotaxime, ceftriaxone, piperacillin, phenytoin, aminophylline, ceftazidime, fluconazole, indomethacin. Drugs administered by IV push : ampicillin+sulbactam, penicillin G potassium, NaHCO3, ranitidine, epinephrine, furosemide, dexamethasone. Drugs administered by IV infusion for at least 60min : acyclovir, amphotericin B, vancomycin, dobutamine, dopamine, doxapram. After each test, the Y injection site and tube below the Y injection site were visually inspected for precipitation and color change. If no particles or color change was detected, the solution was tested and analyzed by a liquid borne particle analyzer (LBPA). RESULTS: White precipitate formed immediately after Y-site administration : phenytoin, aminophylline (undiluted solution), ampicillin+sulbactam (undiluted solution). Number of particles observed with LBPA exceeded the KP guideline limit immediately after Y-site administration and white precipitate formed after 3-4 hour : ceftriaxone, NaHCO3 (1 : 2 diluted solution). CONCLUSION: These results revealed that several lV drugs prescribed in NICU formed precipitate and had a color change, when mixed with neonatal TPN solutions.
Subject(s)
Humans , Infant, Newborn , Acyclovir , Amikacin , Aminophylline , Amphotericin B , Cefotaxime , Ceftazidime , Ceftriaxone , Dexamethasone , Dobutamine , Dopamine , Doxapram , Epinephrine , Fluconazole , Furosemide , Indomethacin , Parenteral Nutrition, Total , Penicillin G , Phenytoin , Piperacillin , Ranitidine , Syringes , VancomycinABSTRACT
PURPOSE: Because vascular access sites in neonates are limited, intravenous (IV) medications must often be mixed with maintenance fluids, including parenteral nutrient (PN) solutions. This study was done to determine whether IV medications commonly prescribed in the neonatal in- tensive care unit (NICU) are compatible with the two neonatal PN solutions. METHODS: The compatibility of neonatal PN solutions and selected other drugs during Y-site delivery was evaluated. Secondary drugs were administered at selected concentrations, rates and delivery by method commonly used at the NICU. Drugs administered by syringe pump over 30min : amikacin, cefotaxime, ceftriaxone, piperacillin, phenytoin, aminophylline, ceftazidime, fluconazole, indomethacin. Drugs administered by IV push : ampicillin+sulbactam, penicillin G potassium, NaHCO3, ranitidine, epinephrine, furosemide, dexamethasone. Drugs administered by IV infusion for at least 60min : acyclovir, amphotericin B, vancomycin, dobutamine, dopamine, doxapram. After each test, the Y injection site and tube below the Y injection site were visually inspected for precipitation and color change. If no particles or color change was detected, the solution was tested and analyzed by a liquid borne particle analyzer (LBPA). RESULTS: White precipitate formed immediately after Y-site administration : phenytoin, aminophylline (undiluted solution), ampicillin+sulbactam (undiluted solution). Number of particles observed with LBPA exceeded the KP guideline limit immediately after Y-site administration and white precipitate formed after 3-4 hour : ceftriaxone, NaHCO3 (1 : 2 diluted solution). CONCLUSION: These results revealed that several lV drugs prescribed in NICU formed precipitate and had a color change, when mixed with neonatal TPN solutions.