Study of distribution of protein of the spine apparatus synaptopodin in cortical brain parts of rats submitted to hypoxia at different periods of embryogenesis

A comparative study of the nervous tissue and distribution of the spine apparatus protein synaptopodin was performed in all layers of the brain sensorymotor cortex and hippocampal CA1 area in control rats and in the rats submitted to hypoxia at E14 and E18. It was found that beginning from the 20th day of postnatal development, in rats submitted to hypoxia both at E14 and E18 there was observed a statistically significant decrease of the mean number of labile synaptopodin-positive spines in the stratum radiatum molecular of the hippocampus area CA1. The decrease of the number of labile spines in the sensorymotor brain cortex was revealed only in the I layer beginning from the 20th day after birth in the rats submitted to hypoxia at E14. Maximal differences in the studied brain areas were observed in adult rats (exposed to hypoxia at E14: in the neocortex--a decrease by 23 +/- 10%, in hippocampus--by 24 +/- 8%, respectively). In adult animals, the increased degeneration of neuzons was not detected. It is suggested that disturbances in cognitive functions and in the capability for learning observed in rats after prenatal hypoxia can be due to a decrease of the amount of the labile synaptopodin-positive spines, which leads to a change of the structural-functional properties of neuronal networks and to a decrease of their plasticity.     

Activation of carbamoyl phosphate synthase by N-acetyl-l-aspartate

Carbamoyl phosphate synthase from liver of both rat and frog, normally dependent on N-acetyl-l-glutamate (on the basis of K(m) and physiological concentrations) as an activator, was shown to be activated by high concentrations of N-acetyl-l-aspartate. However, the high concentrations of N-acetyl-l-aspartate required for activation produce non-competitive inhibition. Similarly, high concentrations of N-acetyl-l-glutamate, in very large excess of the amount required to activate the enzyme, inhibit. The limit for N-acetyl-l-glutamate as an impurity in N-acetyl-l-aspartate was found to be less than 1 in 5000 parts, far below the 1 in 250 parts needed to produce the activation observed with N-acetyl-l-aspartate.     

Direct evidence of the role of propionate in choline synthesis in rats

Wistar rats were injected with 2-14C-propionate in a dose of 30 mu Ci/100 g bw, 2 h after food intake. Two hours after isotope injection the rats were decapitated to determine specific radioactivity (SR) in liver and brain lipids, in liver phosphatidylcholine (PC) and its structural components. The label was incorporated in liver lipids in a far greater amount. In liver PC, SR appeared the highest in glycerin and less higher in the fraction of higher fatty acids. The least amount of the label from 2-14C-propionate was incorporated in choline. The fact of the label incorporation in choline was recorded for the first time.     

Change of the neocortex nervous tissue in rat ontogenesis after hypoxia at various terms of embryogenesis

The performed study has shown that in rats submitted to hypoxia (3 h, 7% O2) at the 14th day of embryogenesis (E14) as compared with control animals, density of disposition of cells in the brain cortex decreased for the first month of postnatal ontogenesis (maximally by 40.8% by P20). In dying neurons, swelling of the cell body, lysis of organoids, and disturbance of the cytoplasmic membrane intactness were observed. Two waved of neuronal death by the mechanism of caspase-dependent apoptosis were revealed; the first involved large pyramidal neurons of the V layer (P10-20), the second--small pyramidal and non-pyramidal neurons of the II--III layers (P20-30). In neuropil of molecular layer, a decrease of the mean amount of labile synaptopodin-positive dendrite spines was observed, as compared with control. In rats exposed to hypoxia at E18, no changes of cell composition and structure of the nervous tissue were found in the studied brain cortex areas. Thus, formation of the cortex nervous tissue in postnatal ontogenesis of rats submitted to hypoxia at the period of neuroblast proliferation-migration is accompanied not only by a change of the cell composition of various cortex layers in early ontogenesis, but also by a decrease of the number of the synaptopodin-positive spines in molecular layer, the decrease being preserved in adult animals.     

Study of distribution of the spine apparatus protein synaptopodin in cortical brain parts of rats exposed to hypoxia at different periods of embryogenesis

A comparative study of the nervous tissue and distribution of the spine apparatus protein synaptopodin was performed in all layers of the brain sensorimotor cortex and hippocampal CAl area in control rats and in the rats exposed to hypoxia at E14 and E18. It was found that beginning from the 20th day of postnatal development, a statistically significant decrease of the mean number of labile synaptopodin-positive spines in the stratum radiatum moleculare of the hippocampal area CAl was observed in rats exposed to hypoxia both at E14 and E18. The decrease of the number of labile spines in the sensorimotor brain cortex was revealed only in the I layer beginning from the 20th day after birth in the rats exposed to hypoxia at E14. Maximal differences in the studied brain areas were observed in adult rats exposed to hypoxia at E14 in the neocortex—a decrease by 23 ± 10%, in hippocampus—by 24 ± 8%, respectively. However, no increased degeneration of neurons was detected in adult animals. It is suggested that disturbances in cognitive functions and in the capability for learning observed in rats after prenatal hypoxia can be due to a decrease of the amount of the labile synaptopodin-positive spines, which leads to a change of the structural-functional properties of neuronal networks and to a decrease of their plasticity.     

Chronopharmacokinetics of imipramine and desipramine in rat forebrain and plasma after single and chronic treatment with imipramine.

Daily variations in the pharmacokinetics of imipramine (IMI) could contribute to circadian phase-dependent effects of the drug. Therefore, the chronopharmacokinetics of IMI and its metabolite, desipramine (DMI), were studied after single and chronic application. Male rats were synchronized to a 12:12 hour light:dark (L:D) regimen with lights on from 07:00 to 19:00 (dark, 19:00-07:00). In single-dose experiments rats were injected with IMI (10 mg/kg) i.p. or i.v. at 07:30 or 19:30 and groups of rats were killed 0-22 hours thereafter. After chronic application of IMI in drinking water (approximately 15 mg/kg/d) groups of rats were killed during the 14th day of treatment at 02:00, 08:00, 14:00, and 20:00, respectively. Brain and plasma concentrations of IMI and DMI were determined by reversed-phase high-performance liquid chromatography with ultraviolet detection. After single i.p. application of IMI, maximal brain concentrations (Cmax) of IMI and DMI were nearly twofold higher in darkness (IMI, 4.8 micrograms/g; DMI, 1.8 micrograms/g) than in light (IMI, 2.85 micrograms/g; DMI, 0.85 microgram/g). Also, the area under the curve (AUC) (0-22 hours) was about 1.6-fold greater in darkness than in light for IMI and DMI; half-lives were not circadian phase dependent. After i.v. injection of IMI, the AUC in brain was also about 30% greater in darkness than in light. After chronic application of IMI in drinking water, brain concentrations of IMI and DMI varied more than threefold within 24 hours. The data demonstrate that the pharmacokinetics of IMI and DMI are circadian phase dependent. It is assumed that circadian variations in drug distribution are more likely to contribute to the drug's chronopharmacokinetics than variations in the drug's metabolism. The 24-hour variations in the drug's concentrations after chronic IMI application in drinking water can be explained by the drinking behavior of the rats, which by itself is altered by IMI.     

Chronopharmacokinetics of Imipramine and Desipramine in Rat Forebrain and Plasma After Single and Chronic Treatment with Imipramine

Daily variations in the pharmacokinetics of imipramine (IMI) could contribute to circadian phase-dependent effects of the drug. Therefore, the chronopharmacokinetics of IMI and its metabolite, desipramine (DMI), were studied after single and chronic application. Male rats were synchronized to a 12:12 hour lightdark (L:D) regimen with lights on from 07:00 to 19:00 (dark, 19:00-07:00). In single-dose experiments rats were injected with IMI (10 mg/kg) i.p. or i.v. at 07:30 or 19:30 and groups of rats were killed 0-22 hours thereafter. After chronic application of IMI in drinking water (≈ 15 mg/kg/d) groups of rats were killed during the 14th day of treatment at 02:00, 08:00, 14:00, and 20:00, respectively. Brain and plasma concentrations of IMI and DMI were determined by reversed-phase high-performance liquid chromatography with ultraviolet detection. After single i.p. application of IMI, maximal brain concentrations (C_max) of IMI and DMI were nearly twofold higher in darkness (IMI, 4.8 μg/g; DMI, 1.8 μg/g) than in light (IMI, 2.85 Mg/g; DMI, 0.85 Mg/g). Also, the area under the curve (AUC) (0-22 hours) was about 1.6-fold greater in darkness than in light for IMI and DMI; half-lives were not circadian phase dependent. After i.v. injection of IMI, the AUC in brain was also about 30% greater in darkness than in light. After chronic application of IMI in drinking water, brain concentrations of IMI and DMI varied more than threefold within 24 hours. The data demonstrate that the pharmacokinetics of IMI and DMI are circadian phase dependent. It is assumed that circadian variations in drug distribution are more likely to contribute to the drug's chronopharmacokinetics than variations in the drug's metabolism. The 24-hour variations in the drug's concentrations after chronic IMI application in drinking water can be explained by the drinking behavior of the rats, which by itself is altered by IMI.     

丁苯酞对脑梗死模型大鼠血清及脑组织突触素及突触后致密物-95表达的影响

摘要 目的：探讨丁苯酞对脑梗死模型大鼠血清及脑组织突触素及突触后致密物（postsynaptic density,PSD）-95表达的影响。方法：将建模成功的大鼠随机平分为三组-丁苯酞组、阿司匹林组与模型组各18只。三组分别给予腹腔注射丁苯酞注射液20 mg/kg+阿司匹林20 mg/kg、阿司匹林20 mg/kg与等体积的生理盐水,1次/d,检测血清及脑组织突触素及PSD-95表达变化情况。结果：（1）治疗第7 d与治疗第14 d后,丁苯酞组和阿司匹林组大鼠改良神经功能评分（Modified neurological severity scores,mNSS）均显著低于模型组（P<0.05）,丁苯酞组低于阿司匹林组（P<0.05）;（2）治疗第7 d与治疗第14 d,丁苯酞组、阿司匹林组大鼠的脑梗死体积百分比均显著低于模型组（P<0.05）,丁苯酞组低于阿司匹林组（P<0.05）;（3）治疗第7 d与治疗第14 d,丁苯酞组、阿司匹林组大鼠血清突触素及PSD-95表达水平均显著高于模型组（P<0.05）,丁苯酞组高于阿司匹林组（P<0.05）;（4）治疗第7 d与治疗第14 d后,丁苯酞组、阿司匹林组大鼠大脑组织突触素及PSD-95蛋白相对表达水平均显著高于模型组（P<0.05）,丁苯酞组高于阿司匹林组（P<0.05）。结论：丁苯酞在脑梗死模型大鼠的应用可促进大鼠血清及脑组织突触素及PSD-95的表达,并减小脑梗死面积,因而有利于大鼠的神经功能的恢复。     

Up-regulation of apelin in brain tissue of patients with epilepsy and an epileptic rat model

Prolonged epileptic seizures or SE can cause neuronal cell death. However, the exact role of neuroprotectant against brain injury during epileptic seizure needs to be further elucidated. The aim of this study was to investigate the expression of the apelin, a novel neuroprotective peptide, in brain tissues of the patients with temporal lobe epilepsy (TLE) and experimental rats using immunohistochemistry, immunofluorescence and Western blotting analysis and to discuss the possible role of apelin in TLE. Thirty temporal neocortical tissue samples from the patients with drug-refractory TLE underwent surgical therapy and nine histologically normal temporal lobes tissues as controls were used in our study. Fifty-six Sprague-Dawley rats were randomly divided into seven groups, including one control group and six groups with epilepsy induced by lithium-pilocarpine. Hippocampus and adjacent cortex were taken from the controls and epileptic rats at 1, 3, 7, 14, 30, and 60 days after onset of seizures. Apelin was mainly expressed in the neurons of TLE patients and controls, and was significantly increased in TLE patients compared with the controls. Apelin was also expressed in the neurons of experimental and control rats, it was gradually increased in the experimental rat post-seizure and reached a stable high level in chronic epileptic phase. Our results demonstrated that the increased expression of apelin in the brain may be involved in human TLE.     

H-Pro-[3H]Leu-Gly-NH2: Plasma Profile and Brain Uptake Following Subcutaneous Injection in the Rat

Following subcutaneous injection of the tripeptide H-Pro-[3H]Leu-Gly-NH2 ([3H]PLG) in rats, the profile of intact peptide and its radioactively labeled metabolites was examined both in plasma and in brain tissue. [3H]PLG and metabolites were determined in trichloroacetic acid extracts by reverse-phase paired-ion HPLC. Maximal plasma levels of unmetabolized PLG were reached 6-8 min after administration, after which they decreased with an elimination half-life of 20 min. The uptake of [3H]PLG in the brain ranged from 0.0013% to 0.0017% of the administered dose per g tissue at 6-30 min following subcutaneous injection. After comparing these results with our previous findings with intravenous injection of [3H]PLG, it seemed likely that the subcutaneous route of administration might be more effective in eliciting CNS effects of PLG than the intravenous route of administration. The metabolite profiles in plasma and brain point to an initial cleavage of PLG at the NH2-terminal side and a very rapid degradation of the peptide intermediate H-Leu-Gly-NH2.     

Glycogenesis and lipogenesis from 14C-glucose in vivo in rats irradiated with fractionated doses of gamma rays

Irradiation with fractionated doses is a specific form of stress and the data concerning these problems are topical for recent radiobiology, radiology and oncology. Interest in this present paper is focused on tissue glycogenesis and lipogenesis from U-14C-glucose in vivo in rats irradiated with fractionated doses of 2.39 Gy once a week. Analyses were done after 1-6 fractions, up to total accumulated doses of 2.39, 4.78, 7.17, 9.76, 11.95 and 14.34 Gy, which means LD50/30 for this experimental model. Fractionated irradiation of rats led to glycogen deposition and increased incorporation of 14C-glucose into the liver, heart and skeletal muscles, but not into brain glycogen. The ascertained changes were not dose-dependent. 14C-glucose was incorporated into the liver and adipose tissue lipids to a small extent, and synthesis of liver cholesterol increased only after the 5th and 6th fractions. A decreased concentration of hepatic lipids, especially of cholesterol, was observed from the 3rd to the 6th fractions.     

DNA-protein cross-links in nuclei and mitochondria of tissue cells from rats of various age exposed to gamma-radiation

The formation and repair of DNA-protein cross-links (DPC) in the mitochondria and nuclei from the brain and spleen of 2- and 29-month rats after their exposure to ionizing radiation were studied. The background level of DPC in brain and spleen mitochondria of old rats was shown to be about two times as high as in young rats. In the nuclei from the brain of old rats the background amount of DPC was also increased, unlike the nuclei of spleen of the same rats. At the doses 5 and 10 Gy (137Cs), the amount of DPC produced in the mitochondria and nuclei of brain and spleen of 29-month rats was 1.8-2.5 times greater than in the nuclei of the same tissues of young animals. At the same time, in the mitochondria of brain and spleen from irradiated rats the amount of DPC was by 30-80% higher than in the nuclei of the same tissues. Analysis of changes in DPC content during the post-radiation period showed that 5 h after irradiation of rats with a dose of 10 Gy, the level of these lesions in the nuclei of brain and spleen of young rats decreased by 40 and 65%, respectively, whereas the amount of these lesions in the mitochondria did not decrease. In this post-radiation period in nuclei of brain and spleen of old rats the amount of DPC decreased by 20-40%, respectively. However, the data on DPC obtained for the mitochondria of brain and spleen from both young and old rats showed that the amount of these lesions did not decrease during the 5 h post-radiation period. These results enable the suggestion that mitochondria do not possess a system of DPC repair. To summarize, ionizing radiation initiates in the nuclei of brain and spleen of old rats more DPC and their repair proceeds slower than in the nuclei of the same tissues of young animals. In the mitochondria of gamma-radiation exposed old rats more DPC are also produced than in young rats but no repair of DPC is observed in both old and young animals within the 5 h post-radiation period.     

Competition among oxidizable substrates in brains of young and adult rats. Dissociated cells.

The rates of conversion of D-(-)-3-hydroxy[3-14C]butyrate, [3-14C]acetoacetate, [6-14C]glucose and [U-14C]glutamine into 14CO2 were measured in the presence and absence of alternative oxidizable substrates in intact dissociated cells from the brains of young and adult rats. When unlabelled glutamine was added to [6-14C]glucose or unlabelled glucose was added to [U-14C]glutamine, the rate of 14CO2 production was decreased in both young and adult rats. The rate of oxidation of 3-hydroxy[3-14C]butyrate was also decreased by the addition of unlabelled glutamine in both age groups, but in the reverse situation, i.e. unlabelled 3-hydroxybutyrate added to [U-14C]glutamine, only the brain cells from young rats were affected. No significant effects were seen when glutamine and acetoacetate were combined. The addition of either of the two ketone bodies to [6-14C]glucose markedly lowered the rate of 14CO2 production in young rats, but in the adult only 3-hydroxybutyrate was effective and the magnitude of decrease in the rate of [6-14C]glucose oxidation was much lower than in young animals. Unlabelled glucose decreased the rate of [3-14C]acetoacetate oxidation to a minor extent in brain cells from both age groups; when added to 3-hydroxy[3-14C]butyrate, glucose had no effect in young rats and greatly enhanced 14CO2 production in adult brain cells. Many of these patterns of substrate interaction in dissociated brain cells differ from those in whole homogenates; they may be a function of the plasma membranes and the role of a carrier-mediated transport system or a reflection of a difference in the population of cell types or subcellular organelles in these two preparations.     

Identification of insulin intermediates and sites of cleavage of native insulin by insulin protease from human fibroblasts

We have studied the time sequence degradation of native insulin by insulin protease from human fibroblast using multiple steps involving purification of the products by high performance liquid chromatography, determination of peak composition by amino acid sequence analysis, and confirmation of structure by mass spectrometry and thus elucidated the sites of cleavage of insulin by human insulin protease. We observed that as early as 0.5 min of incubation, three major new peptide peaks, intact insulin, and four smaller peptide peaks can be detected. The major peptides are portions of the insulin molecule, with the amino ends of the A and B chains or the carboxyl ends of the A and B chains still connected by disulfide bonds. Peptide peak I is A1-13-B1-9. Peptide peak II is A1-14-B1-9. Peptide peak III is A14-21-B14-30. The smaller peptide peaks are A14-21-B17-30, A15-21-B14-30, A15-21-B10-30, and A14-21-B10-30. The major peptide bond cleavage sites therefore consist of A13-14, A14-15, B9-10, B13-14, and B10-17. With longer incubation times, peptide peak II appears to lose the A14 tyrosine to form peptide peak I. This peptide I, which is the amino end of the A and B chains, is not further degraded even after 1.5 h of incubation. With longer incubation times, the peptides containing the carboxyl ends of the A and B chains are further degraded to form products from cleavage at the A18-19, B14-15, B25-26, and a small amount of A19-20, B10-11, and B24-25 cleavage and the emergence of 2-5-amino acid peptide chains, tyrosine, alanine, histidine, and leucine-tyrosine. We conclude, based on the three-dimensional structure of insulin, that human insulin protease recognizes the alpha-helical regions around leucine-tyrosine bonds and that final degradation steps to small peptides do not require lysosomal involvement.     

Regional changes in CNS levels of the S-100 and 14-3-2 proteins during development and aging of the mouse

The levels of the S-100 and 14-3-2 proteins were determined in a number of regions of mouse brain at intervals from 1 day to 30 months of age. Both S-100 and 14-3-2 were found in measurable amounts as early as the first day of postnatal age but did not begin to accumulate rapidly in the forebrain, brain stem and cerebellum of the mouse brain until some time between the 7th and 14th days. From days 14 to 28 the levels of S-100 and 14-3-2 in each region continued to increase rapidly with the exception of the forebrain where the rate of accumulation of S-100 appeared to lag considerably behind that in the other regions. The proteins continued to accumulate at a rapid rate until approximately 6 months of age. From 6 to 30 months of age, the levels of 14-3-2 remained relatively stable in cerebellum, hippocampus and hypothalamus and appeared to decrease slightly in striatum and cerebral cortex. In the case of S-100, the level of the protein increased in all regions of brain from 6 to 30 months but the increase was most pronounced in the hippocampus, hypothalamus and striatum. The principal conclusion derived from this study is that the biochemical development and aging of the central nervous system are regionally selective processes.     

NAAGS基因修饰神经干细胞在创伤性颅脑损伤治疗中的研究

目的：探讨移植NAAG合酶（NAAG synthetase,NAAGS）基因修饰的神经干细胞（Neural Stem Cells,NSCs）能否促进创伤性颅脑损伤大鼠神经功能的恢复。方法：利用电穿孔转染大鼠NSCs,通过脑立体定向仪分别将PBS（模型组）、NSCs（NSCs组）、转基因NSCs（NAAGS＋NSCs组）移植到创伤性颅脑损伤（Traumatic Brain Injury,TBI）大鼠局部损伤灶边缘,通过NSS评分评价移植后大鼠神经功能的变化以及用TUNEL法检测NSCs的凋亡情况,并采用放射免疫法分析脑组织中促炎因子水平。结果：Nss评分结果显示NAAGs＋NSCs组和NSCs组在第7、14、21天神经功能评分均低于模型组（P〈0．05）;NAAGS＋NSCs组在第14和21天神经功能评分低于NSCs组（P〈0．05）;在各时间点细胞移植组比模型组的神经细胞凋亡数明显减少;转基因NSCs移植能明显降低TBI脑组织中促炎因子水平。结论：转基因NSCs移植后可以合成NAAGS促进TBI大鼠神经功能的恢复。     

Ultrastructure of ependyma in brain third ventricle of the rats exposed to repeated tail-suspension. Scanning electron microscopical study

By means of scanning electron microscopy the ultrastructure of ependyma was studied in the brain third ventricle of the rats repeatedly exposed to 14-day tail-suspension (TS). Animals were subjected to TS for 30 days, then readapted to horizontal position during 30 days and again, repeatedly subjected to TS for 14 days simultaneously with the rats which were in TS for the first time during 14 days. Repeated TS of rats, inspite of repeated redistribution of body liquid mediums in cranial direction, results in considerably less expressed destructive changes in ultrastructure of ependymocyte cilia, then after primary 14- and 30-day TS, showing much greater cerebrospinal fluid (CSF) outflow from brain ventricles into sagittal venous sinus at postponed for a long time, repeated simulation of weightlessness effects in comparison with CSF outflow at primery one.     

THE EFFECT OF A LOW PROTEIN DIET AND EXOGENOUS INSULIN ON BRAIN TRYPTOPHAN AND ITS METABOLITES IN THE WEANLING RAT

—Male Wistar rats aged 24 days were divided into three groups. Two groups were given a high protein (250 g/kg casein) and a low protein (30 g/kg casein) diet respectively. The third group was given an amount of the high protein diet containing the same amount of energy as that consumed by the low protein diet rats. The plasma of the animals on low protein contained 20% of the concentration of tryptophan of animals on the other two diets. In these animals the concentration of tryptophan was reduced in the forebrain, cerebellum and brain stem, and the concentrations of 5-HT and 5-hydroxyindoleacetic acid were reduced in the forebrain and brain stem. The low protein diet decreased the total uptake of l -[G-³H]tryptophan into the brain and its incorporation into brain protein. Plasma insulin concentrations were reduced in the low protein and ‘restricted high protein’ animals and the plasma corticosterone concentration was raised in the low protein animals. Exogenous insulin did not raise the plasma tryptophan concentration in the low protein animals but it increased the uptake of l -[G-³H]tryptophan into the brain and its incorporation into protein. Rehabilitation for 7 days restored the plasma and brain tryptophan concentrations and those of brain 5-HT and 5-hydroxyindoleacetic acid to control values.     

Uptake and metabolism of plasma-derived erucic acid by rat brain

We examined the ability of erucic acid (22:1n-9) to cross the blood-brain barrier (BBB) by infusing [14-14C]22:1n-9 (170 microCi/kg, iv and icv) into awake, male rats. [1-14C]arachidonic acid (20:4n-6) [intravenous (i.v.)] was the positive control. After i.v. infusion, 0.011% of the plasma [14-14C]22:1n-9 was extracted by the brain, compared with 0.055% of the plasma [1-14C]20:4n-6. The [14-14C]22:1n-9 was extensively beta-oxidized (60%), compared with 30% for [1-14C]20:4n-6. Although 20:4n-6 was targeted primarily to phospholipid pools, 22:1n-9 was targeted to cholesteryl esters, triglycerides, and phospholipids. When [14-14C]22:1n-9 was infused directly into the fourth ventricle of the brain [intracerebroventricular (i.c.v.)] for 7 days, 60% of the tracer entered the phospholipid pools, similar to the distribution observed for [1-14C]20:4n-6. This demonstrates plasticity in the ability of the brain to esterify 22:1n-9 in an exposure-dependent manner. In i.v. and i.c.v. infused rats, a significant amount of tracer found in the phospholipid pools underwent sequential rounds of chain shortening and was found as [12-14C]20:1n-9 and [10-14C]oleic acid. These results demonstrate for the first time that intact 22:1n-9 crosses the BBB, is incorporated into specific lipid pools, and is chain-shortened.