Targeted migration of stem cells in the model of brain trauma

Objective: to develop technique of stem cells migration to the brain along trunks of cranial nerves during brain injury modeling. Methods: 40 anesthetized white rats were fixed in stereotaxis and subjected to craniotomy (20 rats at anterior cranial fossa (group 1) and 20 rats at posterior cranial fossa (group 2). 100 µl of brain tissue were bilaterally aspirated from somatosensory zone and cerebellar cortex in 1st and 2nd groups, respectively. Mesenchymal stem cells (labeled with PKH67 green fluorescent linker) were injected in 10 minutes: intranasally (10 animals) and to Meckel cavity (10 animals) in both groups. Animals were observed and sacrificed at certain periods of time after the operation during three weeks. Results: Appearance of small groups of mesenchymal stem cells in cranial cavity was established in 30 minutes after the operation. The highest fluorescence was observed at the damaged zone from 14 till 21 day after labeled stem cells implantation. Mesenchymal stem cells were predominantly distributed at the damaged zone in anterior cranial fossa after intranasal injection, and injection of stem cells to Meckel cavity resulted in their pronounced accumulation in the zone of cerebellar cortex injury (posterior cranial fossa). Conclusion: The fact of somatotopic arrangement of mesenchymal stem cells in cranial cavity according to application zone near cranial nerve endings was established. Intranasal injection of mesenchymal stem cells is followed by their distribution in damaged zone in anterior cranial fossa. Injection of mesenchymal stem cells to Meckel cavity leads to accumulation of labeled cells in damaged zone in posterior cranial fossa

Role of the solitary tract nucleus and caudal ventrolateral medulla in temperature responses in endotoxemic rats

In experiments on conscious rats it was found that preliminary microinjection of 100 nl 100 μM glutamic acid to the rostral commissural part of the solitary tract nucleus or to the caudal ventrolateral medulla increased a rise in colonic temperature induced by systemically applied endotoxin (3 µg/kg Escherichia coli lipopolysaccharide, i.p.) as compared to animals with intrabulbar injection of vehicle (control group). Preliminary microinjection of glutamate to the caudal commissural part of the solitary tract nucleus levelled the endotoxininduced temperature response. After glutamate treatment of the caudal ventrolateral medulla there was a significant decrease in the noradrenaline content and decrease in the adrenaline level in the caudal (not significant) and rostral ventrolateral medulla (significant), as well as a small rise in noradrenergic activity at the solitary tract nucleus as compared to control animals. The post-mortem measurement of the optical density of brainstem tissues revealed its significant attenuation at the solitary tract nucleus and caudal ventrolateral medulla after glutamate as compared with these structures after vehicle. The involvement of monoaminergic systems of both structures under study in the initiation and control of temperature responses during endotoxemia is suggested